Pacific Northwest Climate Change: A Review and Preview
John Abatzoglou, University of Idaho
Observations of changes in climate of the northwestern United States generally follow the narrative of climate change observed at continental to global scales with increased temperature and indeterminate change in precipitation over the past century. Regional departures from that narrative at multi-decadal timescales have been observed, including the lack of spring warming and the stark increase in summer temperature over the past three decades. These multi-decadal trends are an expected result of the confluence of climate variability and change and are generally consistent with climate modeling results. Ensembles of global climate model experiments run over the 21st century provide insight into projected changes in regional climate. A coordinated effort to integrate climate scenarios into climate impact assessment is expedited by statistically downscaling daily output from these models for subsequent modeling efforts. Examples of projected changes in both raw climate variables and its derivatives will be presented to facilitate discussion of climate change impacts for the Pacific Northwest.
Will Climate Change Increase the Occurrence of Very Large Fires in the Northwestern United States?
John Abatzoglou, University of Idaho; Renaud Barbero, University of Idaho; Sim Larkin, US Forest Service; Don McKenzie, US Forest Service; E. Ashley Steel, US Forest Service; Dominique Bachelet, Conservation Biology Institute; Tim Sheehan, Conservation Biology Institute
The largest wildfires in the western United States account for a substantial portion of annual area burned and are associated with numerous direct and indirect impacts in addition to commandeering suppression resources and national attention. While substantial prior work has been devoted to understand the influence of climate and weather on annual area burned, there has been limited effort to identify factors that enable and drive the very largest wildfires (VLF). Antecedent climate is found to enable VLF across ecoregions albeit in contrasting ways contingent upon fuel constraints. By contrast, strong commonality of prolonged extremely low fuel moisture and high fire danger coinciding with VLF is found across ecoregions of northwestern US. An empirical generalized linear model is used to project VLF at 50-km resolution and weekly timescales using antecedent and concurrent weather and climate forcings over the historic period and for the mid-21st century using an ensemble of downscaled climate projections from CMIP5 climate models. Widespread increases in VLF likelihood are projected my most models in a changing climate due to an extension of the seasonal window fuels are receptive to fire through protracted summer moisture stress. Results of this statistical approach are further compared to results from a dynamic vegetation model.
BioEarth: Envisioning and Developing a New Regional Earth System Model to Inform Natural and Agricultural Resource Management
Jenny Adam, University of Washington
As managers of agricultural and natural resources are confronted with uncertainties in global change impacts, the complexities associated with the interconnected cycling of nitrogen, carbon, and water present daunting management challenges. Existing models provide detailed information on specific sub-systems (e.g., land, air, water, and economics). An increasing awareness of the unintended consequences of management decisions resulting from interconnectedness of these sub-systems, however, necessitates coupled regional earth system models (EaSMs). Decision makers' needs and priorities can be integrated into the model design and development processes to enhance decision-making relevance and "usability" of EaSMs. BioEarth is a research initiative currently in development with a focus on the U.S. Pacific Northwest region that explores the coupling of multiple stand-alone EaSMs to generate usable information for resource decision-making. Direct engagement between model developers and non-academic stakeholders involved in resource and environmental management decisions throughout the model development process is a critical component of this effort. BioEarth utilizes a bottom-up approach for its land surface model that preserves fine spatial-scale sensitivities and lateral hydrologic connectivity, which makes it unique among many regional EaSMs. This paper describes the BioEarth initiative and provides specific examples of research to utilizing integrated modeling to generate usable information for agricultural and natural resource decision-making.
Pioneering Public Perceptions of Climate Change in the Pacific Northwest
Leigh A. Bernacchi, University of Idaho; J.D. Wulfhorst, University of Idaho; Monica Reyna, University of Idaho; Liza Nirelli, University of Idaho
Despite the relative geographic importance of projected climate change impacts, the Pacific Northwest (PNW) has remained an under-studied region with respect to the general public's attitudes and perceptions of climate change. Even more so, a general public assessment that links perceptions and attitudes to a context of agricultural systems and impacts to regional food production have been completely absent for the PNW, at least within a comprehensive and full-scale research design. Our study was conducted within the context of climate change risks and benefits to PNW agricultural production, food systems and food security; and as a social science component within the large USDA National Institute for Food & Agriculture (NIFA) project, Regional Approaches to Climate Change in Pacific Northwest Agriculture. We conducted a telephone survey of the general public across Oregon, Washington, and Idaho using a stratified random sample, distributed across the region by state, and rural vs urban counties, yielding over 1,300 responses. Within the survey, respondents described changes in observed weather patterns in their lifetime, effects of climate change in the last century, primary causes of climate change, levels of concern about climate change impacts, perceived impacts to family and community, and a series of measures pertinent to how climate change will affect PNW agriculture (e.g., whether crops in the region may change, risk to crop failure, and risk of food shortage). This paper and presentation explores the differences among states and between rural-urban counties in order to describe and analyze the dominant values and perspectives among the general public on these issues. Implications of this research contribute to understanding the baseline of climate perceptions in the region and could inform institutional adaptations.
Persistent High Pressure over the NE Pacific during the Winter of 2013-14: Upper Ocean Response and Implications for the Weather of the Pacific Northwest in Summer 2014
Nicholas A. Bond, University of Washington; Meghan F. Cronin National Oceanic and Atmospheric Administration; Karin Bumbaco University of Washington
A remarkably strong ridge of high sea-level pressure was present over the Northeast Pacific Ocean in a mean sense from October 2013 through early February 2014. This feature of the regional atmospheric circulation was associated with suppression of the usual parade of storms into the Pacific Northwest, leading to a period of relatively quiet and dry weather for the season. In addition, it caused the development of positive temperature anomalies exceeding 2 degrees C in the upper ocean off the coast between roughly 40 and 55 N, and 160 and 130 W. The evolution of these temperature anomalies, and other upper ocean properties, was directly observed with a highly-instrumented buoy moored at 50 N, 145 W (Station P). The warmth can be attributed to a combination of anomalous downwelling, poleward Ekman transports, and reduced heat fluxes at both the air-sea interface and the base of the mixed layer. The signal in the upper ocean temperature has persisted into the spring of 2014; global climate models used for seasonal weather prediction are indicating that it will remain, or even be reinforced, through the winter of 2014-15. The presence of anomalously warm water off the coast of the Pacific Northwest favors sub-tropical plankton species, with impacts for the entire marine food web. Past occurrences of such a water mass have also tended to be accompanied by relatively warm and humid weather in the Pacific Northwest in late summer. It will be interesting to see if the summer of 2014, which is liable to also feature an intensifying El Nino, will play out in a similar fashion.
Changes in Pacific Northwest Heat Waves under Anthropogenic Global Warming
Matthew Brewer, University of Washington; Cliff Mass, University of Washington
Though western Oregon and Washington summers are typically mild due to the influence of the nearby Pacific Ocean, this region occasionally experiences heat waves with temperatures in excess of 35ºC. Heat waves can have a substantial impact on this highly populated region, particularly since the population is unaccustomed to and generally unprepared for such conditions. Initial studies suggest that heat waves over the Pacific Northwest will increase in frequency under anthropogenic global warming. However, a more comprehensive evaluation is needed of past and future heat wave trends. This talk will describe a threshold definition of heat waves that are applied to GCM and downscaled model output at the surface for a distributed set of locations over the Pacific Northwest. Trends in Pacific Northwest heat wave intensity, duration, and frequency during the 21st century (through 2100) will be discussed. Also, the spatial distribution in the trends in heat waves, and the variability of these trends at different resolutions and among different models will also be described.
Current, Historical, and Future Weather Suitability for Mountain Pine Beetle Outbreaks in Lodgepole Pine Forests
Polly C. Buotte, Department of Geography, University of Idaho; Jeffery A. Hicke, Department of Geography, University of Idaho; Haiganoush K. Preisler, Statistical Scientist, USDA Forest Service Pacific Southwest Research Station
Mountain pine beetles (Dendroctonus ponderosae Hopkins) are a native disturbance agent in lodgepole pine forests of western North America. When weather conditions are suitable, mountain pine beetle populations increase and cause widespread tree mortality. Weather conditions affect beetle development and survival as well as the ability of trees to defend themselves against attack. Our goals here are to understand the influence of weather on the recent mountain pine beetle outbreaks in lodgepole pine forests, evaluate changes in weather suitability over the past century, and estimate future weather suitability. We use an empirical approach to develop generalized additive models of the probability of tree mortality from mountain pine beetles. We use observations from USDA Forest Service aerial surveys to determine the presence of lodgepole pine mortality from mountain pine beetles. Our explanatory variables represent processes affecting mountain pine beetle development, host tree susceptibility, the number of attacking beetles, and stand structure. Once model selection and evaluation is complete, we will apply the best models to historical weather data and to downscaled future climate projections from ten global climate models for three 30-year time periods given three emissions scenarios. Our results will show trends in weather suitability for mountain pine beetle outbreaks over the past century and estimates future weather suitability. This work is part of the Forest Mortality, Economics, and Climate project being conducted by an interdisciplinary team of scientists from Oregon State University (OSU), the University of Idaho (UI), the University of Oxford, and the UK Met Office Hadley Centre to study the causes of severe forest die-offs in western North America, then learn to predict and avoid these events. The project goals are to enhance existing earth system models and economic models, then couple them to elucidate the interactions and feedbacks among climate, tree mortality, and economic factors.
Relative Climate Change Sensitivity of Species in the Pacific Northwest
Michael J. Case, University of Washington; Joshua J. Lawler, University of Washington; Jorge A. Tomasevic, University of Washington
Climate change affects plant and animal species across North America in a myriad of ways. However, not all species respond similarly to climatic change, with some being more inherently sensitive than others. Therefore, managing species in the face of such change will require an understanding of which species will be most susceptible to future climate change and what factors will lead to increased vulnerability or resilience. The inherent sensitivity of species to climate change is influenced by many factors, including physiology, life history traits, interspecific relationships, habitat associations, and relationships with disturbance regimes. Using a combination of scientific literature and expert knowledge, we assessed the relative sensitivity to climate change of 196 plant and animal species in the Pacific Northwest region of North America. We found that although there are highly sensitive species in each of the taxonomic groups analyzed, amphibians and reptiles tended to be more sensitive to climate change. We also explored the relative contribution of different factors to sensitivities across taxonomic groups and found that a dependency on one or more sensitive habitats was the most often highly ranked factor for birds, mammals, and amphibians and reptiles. We then demonstrated how sensitivity and expert confidence information can be combined to prioritize management action and future research needs. Such publically available information will increasingly enable managers to identify which species are more sensitive and identify the key aspects that can be leveraged to increase resilience in the face of climate change. By focusing on the inherent sensitivity of species, our results provide a foundation for anticipating the effects that climate change will have on biodiversity in the Pacific Northwest.
Does Snowpack Sensitivity to Warming Temperature Differ Across the East/West Divide of the Cascade Mountains?
Matthew G. Cooper - Contact author. College of Earth, Ocean, and Atmoshperic Sciences, Oregon State University; Anne W. Nolin. College of Earth, Ocean, and Atmoshperic Sciences, Oregon State University; Mohammad Safeeq. College of Earth, Ocean, and Atmoshperic Sciences, Oregon State University; Eric A. Sproles. Centro de Estudios Avanzados en Zonas Aridas, Chile.
It is well established that climate warming is driving the gradual decline of annual snowpack in the Oregon Cascades, yet we lack watershed-specific predictions for sensitivity across the range. We present a modeled comparison of snowpack sensitivity to warming temperature across the east-west divide of the Oregon Cascades. The west side receives significantly more annual precipitation (2000 mm vs. 600 mm), is more humid during winter on wet days (82% vs. 73% RH) and has lower average winter wet day temperature (3.8oC vs. 4.4oC). While previous studies have focused on the west side of the Cascades, to date, no study has examined impacts on snow over both sides of the range. This study examines the effect of warming temperatures on present day and future snowpack dynamics in the headwater catchments of the McKenzie (west side) and Metolius (east side) River Basins. We employ a process-based, spatially distributed model, SnowModel, to quantify snow accumulation and ablation. We run the model at 100-m spatial scale on a daily time step. The modeling period covers 1989-2011, during which time the region experienced high, low, and average snow water equivalent (SWE). For each basin, we quantify the date and magnitude of peak SWE, the date of snow disappearance, the ratio of SWE to winter precipitation, and the snow-covered area at peak SWE for each year. We validate our model results using available SWE measurements and snow extent from Landsat imagery. SnowModel is then run using perturbed meteorological input data (+2°C, +4°C and ±10% precipitation) to evaluate the potential impacts of a warmer, wetter/drier winter climate on snowpack accumulation and melt in the watersheds. Simulations of SWE in the McKenzie and Metolius Basins for the study period have Nash-Sutcliffe efficiencies of 0.83 and 0.84, respectively. Spatial accuracy derived from Landsat imagery is 82%. Results from the future climate simulations (+2°C) show a 59% reduction in basin wide volumetric water storage in the McKenzie and 42% in the Metolius; whereas simulations with +2°C and +10% precipitation show 53% and 34% reductions, respectively, highlighting a potential difference in the temperature dependence of sensitivity on either side of the range. Both sides of the range show future average SWE below the 25th percentile of historical conditions. This study is part of a larger project examining potential impacts of changing peak streamflows on geomorphology and aquatic species in headwater catchments of the Oregon Cascades.
The Carbon Sequestration Benefits of Large Scale Tidal Wetlands Restoration in Puget Sound: A Case study of the Snohomish Estuary
Steve Crooks, Environmental Science Associates; John Rybczyk, Western Washington University; Keeley O'Connell, EarthCorps; Danielle L. Devier, Environmental Science Associates; Katrina Poppe, Western Washington University; Steve Emmett-Mattox, Restore America's Estuaries
A 'blue carbon' study was conducted in the Snohomish Estuary in Washington State's Puget Sound in order to track how substantial land use alterations have influenced soil carbon cycling in the past and how restoration of tidal wetlands can influence carbon dynamics, including sequestration, in the future. Conversion of broad swaths of the estuary to agriculture with associated diking and draining of wetlands resulted in substantial ecological changes, including carbon dynamics. The combination of soil subsidence due to oxidation of organic materials, pumping of groundwater, and clearing of vegetation resulted in the mobilization of vast carbon stores throughout the estuary. Soil subsidence from 1 to 4 feet is apparent in many locations, changing the landscape's relationship to the tides. This study collected soil carbon content from a range of conditions throughout the Snohomish Estuary, including undisturbed forested and emergent wetlands, recovering emergent wetlands, and agricultural lands. Along with soil carbon content, sediment accretion rates in natural and recovering wetlands were measured to assess potential rates of aggradation within subsided portions of the estuary. The results of the soil carbon and aggradation rates were then integrated over the estuary to investigate how large scale wetland restoration could influence carbon stores at a landscape scale. The influence of sea level rise was considered, as rising tidal influence will drive ecological changes throughout the range of intertidal habitats. Results from this study indicate that net carbon sequestration is likely and suggests that a broader application of this approach could provide additional support to coastal restoration efforts.
A Comprehensive Review of 1300 Papers on Climate Impacts on Salmon: What Have We Learned in the Last 5 Years?
Lisa G. Crozier, NOAA-Fisheries
The diverse and complex life histories of salmon make them an especially valuable resource and model system for understanding the ecological impacts of climate change. I have conducted an annual literature review of the effects of climate and projections of climate change on Pacific salmon since 2008. I will summarize the results of these reviews, including over 1300 publications since 2007. These are primarily peer-reviewed publications from the primary literature, but synthesis reports will also be described. I will outline the impacts expected for salmon, and how our understanding and projections of these impacts has changed over the last 5 years. This review consolidates a huge amount of information and will provide stakeholders with a strong overview of what literature is available and point them to databases to get the information they need on any specific topic.
Piloting Utility Modeling Applications: The Co-Production of Water Utility Climate Change Impact Assessment Between Seattle Public Utilities and the Climate Impacts Research Consortium
Meghan Dalton, Oregon State
The Piloting Utility Modeling Applications project connects the climate science expertise of NOAA Regional Integrated Sciences and Assessments (RISA) with water utility modeling of the Water Utility Climate Alliance to assess impacts of climate change to water utility managers. The Climate Impacts Research Consortium (CIRC), the Pacific Northwest's RISA, has teamed up with Seattle Public Utilities (SPU) to define research questions surrounding water supply, management of stormwater systems, and water quality. We describe results on projected changes in climate within the Cedar and Tolt River watersheds from general changes in seasonal temperature and precipitation to more tailored operational metrics, such as the annual maximum 5-day precipitation amount, the timing of the return of fall rains, the occurrence of atmospheric river events, high fire danger, and the magnitude and timing of El Niño-Southern Oscillation and Pacific Decadal Oscillation cycles.
SPU uses a three-stage modeling approach to assess supply and yield. Weather stations provide input data to a hydrology model and the hydrology output is then input to systems models. To assess future water supply, SPU needs future hourly climate data downscaled to those key weather stations. CIRC statistically downscaled daily data from twenty global climate models (GCMs) for the period 1950-2100 using the Multivariate Adaptive Constructed Analogs (MACA) method with an additional bias-correction step at each station location. The daily data was disaggregated to the hourly time-step using SPU's transform functions. In order to understand the strengths and limitations of the climate data, CIRC evaluated both the original monthly GCM data over the Pacific Northwest (Rupp et al., 2013) and the downscaled data at the station locations for a suite of statistics and operationally important metrics. Statistical downscaling largely corrects GCM biases in mean quantities and across the distribution, but cannot correct model biases in inter-annual variability, serial correlation, or daily sequencing which remain important characteristics for modeling hydrology. Results of SPU's hydrology and systems modeling are described in a companion presentation.
Possible, but Likely? Assessing the Socio-economic and Technological Assumptions underlying Energy-emissions Scenarios
Steve Davis, University of California Irvine
The different representative concentration pathways (RCPs) used by the IPCC have been realized as a wide range of socio-economic and energy-emissions scenarios. Although these scenarios are intended to encompass the possible, some of them entail technological transitions that are more or less plausible than others when considered in the context of history, existing energy infrastructure, and current socio-economic trends.
For instance, RCP4.5, which would stabilize atmospheric CO2 at roughly twice pre-industrial levels (550 ppm) while also sustaining economic growth, requires the carbon intensity of the global energy system (kg C/GJ) to decrease by 75% over the next 60 years, from ~20 kg C/GJ to 5 kg C/GJ. This amounts to a global decarbonization rate (i.e. the rate of decrease in CO2 emissions per unit GDP) of nearly 2% per year between now and 2050. Meanwhile, RCP2.6, which would probably allow global temperatures to stabilize at less than 2°C of warming since the preindustrial, would require decarbonization of ~4.5% per year through 2050.
In contrast, in the quarter century between 1985 and 2010, the global economy has decarbonized at an average rate of only 0.8% per year, and in the decade between 2000 and 2010, the global economy has carbonized at an average rate of 0.6% per year. It's also true that more coal-fired power plants were built 2003-2013 than in any previous decade. Assuming currently existing fossil infrastructure operates for its expected lifetime, we are committed to emit roughly 200 Pg C.
In this talk, I'll present a framework helpful for understanding future energy-emissions scenarios, assess each of the RCPs in turn using the framework, put the implied futures in historical perspective, discuss important drivers of recent emissions, and then show some relevant new estimates of "committed" emissions.
We have known for some time that in order to stabilize global climate, humanity must transform the global energy system into one that does not use the atmosphere as a waste dump. It is important that researchers who are working to anticipate the impacts of climate change and facilitate adaptation to those changes by human and natural systems do not confuse possible with likely: Judging by even our gloomiest scenarios (i.e., RCP8.5), the required energy transformation is behind schedule.
Dancing with the Management Stars: Science-Management Partnerships that Provide Actionable Science
Nicole DeCrappeo, Northwest Climate Science Center
The Department of the Interior Northwest Climate Science Center (NW CSC) is firmly committed to supporting management-relevant science and strongly encourages its funded researchers to work closely with resource managers throughout the life of their projects. During this special session, the NW CSC will showcase three science-management partnerships that will enable the development of actionable science for managers, decision makers, and other stakeholders to use. Management partners with whom NW CSC-funded scientists have worked closely during the course of their project will provide the management context, i.e., the management issues, needs, or decisions they were facing and what scientific information they felt was necessary to help move them forward. There will be a discussion of the process the scientists and managers went through to engage one another (e.g., via an advisory committee, through workshops or monthly phone calls, etc.) and how the needs of all involved in the project were met. Finally, the scientist will describe the information, maps, or other decision support tools that were developed through the project to help address the management need. Throughout the presentations in this special session, the emphasis will be on the science-management partnership, the process developed to engage one another, and how the study's results will be used in a management context.
Using Inundation Modeling and Sum Exceedance Values to Predict Wetland Land Cover Distribution under Alternative Sea Level Rise and Tide Gate Management Scenarios
Heida L. Diefenderfer, Pacific Northwest National Laboratory, Marine Sciences Laboratory; Amy B. Borde, Pacific Northwest National Laboratory, Marine Sciences Laboratory; André M. Coleman, Pacific Northwest National Laboratory, Hydrology Group
Changes in the areal extent and distribution of coastal wetlands caused by sea level rise are occurring less rapidly in the Pacific Northwest than in other coastal areas such as the southeastern United States. The purpose of this paper is to demonstrate the use of two modeling tools to predict wetland land cover distribution under alternative sea level rise and tide gate management scenarios: the sum exceedance value and the spatially based area-time inundation index model (ATIIM). The study area was Baker Bay, near the mouth of the Columbia River, where relative sea level change at Astoria, Oregon remains negative. Due to the proximity to the Pacific Ocean and location in the Columbia River floodplain, climate-related vulnerabilities in this location involve both inland hydrology and coastal processes. The degree of connectivity of tidal wetlands, e.g. tide gate management, is a factor in scenario-based planning as well as an analogous system. We developed the 50-year planning scenarios based on 82 yrs of tide gage data at Astoria from 1925, using a coastal calculator published by the National Oceanic and Atmospheric Administration (NOAA) and U.S. Army Corps of Engineers (USACE), which estimated relative mean sea level change between -0.03m (NOAA and USACE "low" scenarios) and +0.46m (NOAA "intermediate-high" scenario). Specific study sites were the Chinook River estuary, East Sand Island, and two reference wetlands. In this research, the sum exceedance value (SEV; cumulative sum of the difference between hourly water surface elevation and land elevation during the growing season), used as an indicator for vegetation communities, was calculated based on reference wetland data in Baker Bay. Then, SEVs were calculated from outputs of hydrodynamic models for sea level rise scenarios at East Sand Island and tide gate management scenarios at the Chinook River estuary and validated against existing vegetation. We employed the geographic information system based ATIIM, which incorporates high-resolution elevation data and hydrologic inputs and evaluates hydrologically connected areas, to display the spatial extent of predicted vegetation communities and calculate habitat opportunity for target wildlife species under the scenarios. This research was conducted to support climate adaptation planning as part of a National Environmental Policy Act process, and for ecosystem restoration planning in response to a Biological Opinion on endangered salmon and steelhead.
Including Indicators of Indigenous Community Health in Climate Change Impact Assessments
Jamie Donatuto, Swinomish Indian Tribal Community; Larry Campbell, Swinomish Indian Tribal Community; Sarah Grossman, Swinomish Indian Tribal Community; John Konovsky, Tsleil-Waututh First Nation; Eric Grossman, USGS, Pacific Coastal and Marine Science Center
This presentation describes a pilot study evaluating the sensitivity of Indigenous community health to climate change impacts on Salish Sea shorelines (Washington State, United States and British Columbia, Canada). Current climate change assessments omit key community health concerns, which are vital to successful adaptation plans, particularly for Indigenous communities. Descriptive scaling techniques, employed in facilitated workshops with two Indigenous communities, tested the efficacy of ranking six key indicators of community health in relation to projected impacts to shellfish habitat and shoreline archaeological sites stemming from changes in the biophysical environment. Findings demonstrate that: when shellfish habitat and archaeological resources are impacted, so is Indigenous community health; not all community health indicators are equally impacted; and, the community health indicators of highest concern are not necessarily the same indicators most likely to be impacted. Based on the findings and feedback from community participants, exploratory trials were successful; Indigenous-specific health indicators may be useful to Indigenous communities who are assessing climate change sensitivities and creating adaptation plans.
Building Adaptive Capacity at Seattle Public Utilities
Paul Fleming, Seattle Public Utilities
This portion of the special session will focus on Seattle Public Utilities' (SPU) efforts to move beyond assessments to build adaptive capacity for the organization. This evolution is necessary so that SPU has the ability to adapt over time and protect its assets and infrastructure and continue to provide essential utility services. The presentation will highlight SPU's climate program objectives, and the associated initiatives and activities, which serve as foundational elements in building adaptive capacity. These objectives include: enhance knowledge, assess impacts and vulnerabilities, establish collaborative partnerships, strengthen institutions and people and mainstream adaptation into decision-making.
Piloting Utility Modeling Applications: Seattle Public Utilities Use of Downscaled Climate Data to Test the Sensitivity and Vulnerability of Seattle's Water Supply
Paul Fleming, Seattle Public Utilities
Seattle Public Utilities (SPU) is conducting its third climate impacts assessment as part of a broader project called Piloting Utility Modeling Applications (PUMA). PUMA involves five water utilities paired with climate research organizations to obtain and use downscaled climate data to conduct impacts assessments. SPU has partnered with the Climate Impacts Research Consortium (CIRC) through the PUMA project. A related abstract for oral presentation was submitted by CIRC with the intent of these two presentations being presented sequentially.
This presentation will explain the genesis and rationale for the research questions SPU identified for the PUMA project and the locations we selected to have climate data downscaled to. In addition, it will describe the internal chain of models approach that enabled SPU to generate 40 climate-altered hydrologic datasets and conduct a yield/supply impacts assessment, as well as the "bottom-up" identification of system-specific metrics of interest to SPU. Finally, it will highlight the results of the assessment and how SPU intends to use the information going forward.
The Interacting Roles of Climate and Soil in Plant Species Range Shifts in the Subalpine and Alpine Meadows of Mount Rainier National Park
Kevin Ford, USDA Forest Service Pacific Northwest Research Station; Janneke Hille Ris Lambers, Department of Biology, University of Washington
The Pacific Northwest's subalpine and alpine meadows are critical to the region's biodiversity because of their unique suite of plant species and the important wildlife habitat they provide, but are sensitive to changes in climate. Ecologists expect anthropogenic climate change to lead to the upward movement of the meadows as trees encroach from below and meadow plants colonize bare ground above. However, climate is not the only constraint on plant performance in these habitats, with soil quality being another important factor that also varies dramatically across elevation. Bare soils above the meadows have much lower organic matter content, water holding capacity and concentrations of key nutrients compared to lower elevation meadow soils. And while climate is likely to change rapidly in the coming decades, soil development will likely be relatively slow. Thus, seedling establishment above a species' current range may be inhibited by soil conditions even if the climate becomes suitable. To address these issues, we conducted a manipulative experiment at Mount Rainier National Park where we exposed seedlings from tree and meadow species to different combinations of climate and soil conditions and monitored establishment success. Specifically, we transplanted seedlings across the elevational range of the meadows into plots where we measured microclimate, and within each plot planted half the seedlings in soil collected from the lower margin of the meadows and half in soil from bare ground above the meadows, for a total of 4,081 seedlings from seven species. Climate and soil had important and interacting effects on seedling establishment. Initial survival was generally lower where snow disappeared earlier in the year, but the decrease in survival tended to be less severe for seedlings in meadow soil compared to bare soil. In addition, the size of surviving seedlings was generally greater where snow disappeared earlier, but only in meadow soil. Thus, as snow disappears earlier due to climate change, seedlings in meadow soils are likely to experience greater establishment success compared to those in bare soils. This suggests that trees establishing in meadows will undergo relatively rapid upward range expansions, at the expense of the shade-intolerant meadow species, while meadow plants colonizing bare ground will experience relatively slow range expansions at their upper range limits. Together, the results indicate that the meadows will contract at their lower limit faster than they expand at their upper limit, possibly leading to reductions in the geographic extent of the meadows.
Regional Patterns of Evolving Glacio-Hydrologic Processes in the Pacific Northwest
Chris Frans, University of Washington; Christina Bandaragoda, University of Washington; Erkan Istanbulluoglu, University of Washington; Dennis P. Lettenmaier, University of Washington
Recession of mountain glaciers in partially glacierized headwater catchments of the Pacific Northwest (PNW) has the potential to impact watershed dynamics in a range of ways, including reduced low flows, rapid erosion of exposed steep soils, increased sediment transport, and ecosystem succession. The response of glaciers and glacierized watershed processes to progressive climatic warming will vary greatly with local environmental attributes (aspect, hypsometry, slope, debris cover) and climatic forcing (topography driven climatic gradients, prevailing wind direction, precipitation variability and perturbation). To explore the relative influence of these controlling factors and to define spatial thresholds where these changes will have significant influence on stream discharge, we apply a distributed hydrologic modeling framework, which incorporates a physical representation of dynamic changes in glacier mass and area, to evaluate the hydrologic response of glacier change in the PNW at a range of spatial and temporal scales. This model construct, constrained by available hydrologic measurements (stream discharge, snow water equivalence) and glaciological measurements (glacier mass balance, satellite derived glacier area estimates), allows the analysis of hydrologic and glaciological change at extended temporal and fine spatial scales. Parallel analyses of the available local and remote measurements are used to validate and complement the model results. A sample of basins including the Hoh River on the Olympic Peninsula, the Hood River in Northern Oregon, the Nisqually River in Central Washington, and multiple watersheds in the North Cascades are used to 1) describe differential patterns of coupled glacio-hydrologic response 2) identify influential environmental controls and 3) identify vulnerable areas in space and time. Improved understanding of the differential response of watershed processes to glacier recession will have critical implications for the management of water and natural resources in the PNW region.
Contributions of Interdisciplinary Social Science for Advancing Climate Adaptation Research
Shannon Hagerman, University of British Columbia
Interdisciplinary social-science research has much to contribute to advancing the science and practice of adaptation. Adaptation activities are implemented in particular social-political contexts where institutional capacity, regulatory obligations and attitudes across stakeholders differ, political will varies, and competing objectives are at stake. Yet the potential contributions of social science for advancing climate adaptation research are often narrowly identified as improving communication or providing decision support. Social science research is poised to provide additional and crucial insights into the myriad human dimensions of adaptation including providing an understanding of the roles of institutions and social processes that combine with biological vulnerabilities to shape adaptive capacity (the potential for adaptation at various scales) in particular systems.
This talk illustrates some of the insights that interdisciplinary social science approaches can provide through a case study that examines the social (e.g. values, attitudes, trust, leadership) and institutional (e.g. regulatory obligations, intra-agency objectives, access to knowledge), dimensions that shape how federally mandated adaptation initiatives within the United States Forest Service are unfolding across National Forests in the Pacific Northwest (PNW) Region. This study focuses specifically on adaptation decisions for aquatic ecosystems and is part of a broader project that includes the development of a climate adaptation handbook. Based on semi-structured interviews (N = 25) with aquatic resources and management specialists working within the PNW region, this study reveals significant intra-regional variation in terms of the extent of, and attitudes towards adaptation. While managers and specialists widely acknowledge the importance of regionally specific impacts products, variation in progress towards adaptation across the region is best explained not by access to knowledge, but by legacies of past management, current social capital (especially human resources), existing institutional and regulatory commitments, and the presence or absence of a committed leader.
These findings bring the increasingly comprehensive collection of climate impacts knowledge and excellent prescriptive frameworks, into closer conversation with the much sparser literature on empirically based examinations of the social and institutional dimensions of adaptation implementation in practice. The integration of social science and impacts-related contributions is crucial to ensure the long-term sustainability of adaptation initiatives in practice.
Interactions of Climate and Land Use Change with Water Resources in the Pacific Northwest
Roy Haggerty, Oregon State University
An urgent challenge is ensuring an adequate quantity and quality of water for human and ecosystem needs in the Pacific Northwest in light of increasing demand and climate change. This session will present advances in our understanding of the interactions between the water system, climate, and land use changes, including agriculture, managed forest and rangeland systems, the built environment, human decisions, ecosystem services and climate change/variability. This session will include presentations of water systems using models and observations at specific sites, combinations of sites, and regionally; and allow for integration across the different processes.
A Macroscale Glacier Model to Evaluate Climate Change Impacts in Columbia River Basin
Joseph Hamman, University of Washington; Bart Nijssen, University of Washington, Dennis P. Lettenmaier, University of Washington; Bibi Naz, Oak Ridge National Laboratory; Jeremy Fyke, Los Alamos National Laboratory
Glaciers can play an important role in the long-term and seasonal hydrologic cycle by transporting ice from higher to lower elevations where it melts, contributing to streamflow. These glacier effects must be taken into account when evaluating climate change in highly glaciated areas, such as the Columbia Icefield in the Columbia River‘s Canadian headwaters. Most macroscale hydrologic models do not explicitly represent ice or glacier dynamics, leading to continuous accumulation of snow and ice at high elevations and possible biases in streamflow timing and volume, especially in the summer months. We have added a glacier representation to the Variable Infiltration Capacity (VIC) macroscale hydrologic model, including snow to ice transformation, ice redistribution, and ice melt. The distribution of ice within each VIC grid cell is based on a well-established scaling relationship between glacier area and glacier volume. Validation of the newly added VIC glacier representation is accomplished by comparing simulated glacier extent, volume, and vertical distribution to ground and satellite observations. The influences of glacier processes on Columbia River basin hydrology are evaluated by comparing parallel 1/16th degree VIC simulations, driven by historical and future atmospheric forcings, with and without the glacier representation This presentation will discuss the development, application, and validation of the VIC glacier model used in this study and will show results from model simulations for historical and future time periods for the glaciated part of the basin.
Assessing Climate-Change Risks to Cultural and Natural Resources in the Yakima River Basin, Washington
James Hatten, U.S. Geological Survey; Alec Maule, U.S. Geological Survey; Steve Waste, U.S. Geological Survey (Presented by Jill Hardiman, U.S Geological Survey)
We provide an overview of an interdisciplinary study that examined the influence of climate change on people and fish in the Yakima River Basin, USA. Specifically, we addressed stakeholder-relevant climate change issues, such as water allocation and Yakama Tribal cultural values, with decision analysis tools. We also simulated the effects of climate change on stream temperatures, juvenile steelhead growth, and availability of salmonid habitats under baseline conditions (1981 – 2005) and two future climate scenarios (increased air temperature of 1 °C and °2 C). Our simulations indicated that future summers will be a very challenging season for salmonids when low flows and high water temperatures can restrict movement, inhibit or alter growth, and decrease habitat. While some of our simulations indicated salmonids may benefit from warmer water temperatures and increased winter flows, the majority of simulations produced less habitat. The floodplain and tributary habitats we sampled are representative of the larger landscape, so it is likely that climate change will reduce salmonid habitat potential throughout particular areas of the basin. Management strategies are needed to minimize potential salmonid habitat bottlenecks that may result from climate change, such as keeping streams cool through riparian protection, stream restoration, and the reduction of water diversions. An investment in decision analysis and support technologies can help managers understand tradeoffs under different climate scenarios and possibly improve water and fish conservation over the next century.
Finding a Common Language: Building Science to Match Forest Planning Needs in Southwest Oregon
Emilie Henderson, Institute for Natural Resources, and Terry Fairbanks, Bureau of Land Management
Forest management planning in southwest Oregon must address significant challenges. National priorities, community needs and ecological realities must be integrated. Accurate information about how management will interact with future ecological realities is crucial for plans designed to meet those priorities and needs. Building that information is a collaborative process. Conversations between scientists working through the Institute for Natural Resources (INR) and the Bureau of Land Management (BLM) highlighted that an accurate map of current vegetation potential was needed by both. BLM needed the map for the current Resource Management Plan (RMP) revision, a process that began in the Fall of 2013. INR needed the map as a baseline for scenario modeling. Conversations about building that map centered on precisely defining the vegetation classification used. Those conversations led to more, this time about the forest management plans that BLM is refining for each vegetation type. These forest management plans address concerns about wildfire risk management, forest production and habitat for the northern spotted owl. We discussed forest management in the context of how the landscape has operated under recent climate. We designed modeling scenarios under the assumption that patterns of the past will continue in the future (a necessary simplifying assumption at the time). We worked with state-and-transition models (STMs) that were developed to illustrate how silviculture and vegetation dynamics interact within the region's vegetation types. These STMs can represent forest dynamics under recent climate, but do not apply to future climate. However, there is strong agreement between the BLM and other regional stakeholders interested in landscape-scale management that incorporating future climate in planning efforts is critical. Over the next several decades, warmer temperatures and a longer fire season are likely. We are modifying our STMs with information from a dynamic global vegetation model (called MC2) to address those impending changes. We expect to illustrate whether current plans will be adequate to contain future fire risk and maintain northern spotted owl habitat in the region. As the BLM moves forward with their plan revision, we hope that the science will yield directly relevant information. At this stage, we are optimistic. Our early conversations about mapping the present gave us a common language that has become a useful bridge for spanning the gap between science and management as we look to the future.
The Hydrodynamic Response of Pacific Northwest Estuaries to Climate Change-Driven Boundary Conditions
David Hill, Oregon State University; Tiffany Cheng, Oregon State University; Jordan Beamer, Oregon State University; Gabriel Garcia, Oregon State University; Kai Parker, Oregon State University
The hydrodynamic response of Tillamook Bay, Oregon, to climate change-driven boundary conditions has been investigated as a 'case study' for Pacific Northwest (PNW) estuaries in general. Water elevations (and associated flooding) in PNW estuaries are controlled by domain geometry (estuary bathymetry), ocean forcing (offshore waves, tides), direct surface forcing (winds, pressure) and terrestrial forcing (streamflow). All of these controls will change, to varying degrees, on the decadal to century time scale. A comprehensive effort to model the physical response of estuaries to these changing conditions has not previously been attempted.
The coupled wave-surge model ADCSWAN was used to perform a 20 year hind-cast and a 30 year forecast of the hydrodynamic climate in Tillamook Bay. Model boundary conditions were obtained from a variety of related models (WaveWatch III, HydroFlow, etc.), all of which were forced with bias-corrected GCM data. The modeling results provide complete multi-decadal time series of water elevations throughout the domain. These data allow for statistical analysis of exceedance probabilities and extreme water levels. Of particular interest is how these water level statistics change due to the climate-change driven boundary conditions and their interactions.
Confronting Climate Change Heat-Health Risks in the Pacific Northwest
Tania Busch Isaksen, University of Washington
Climate change is projected to have serious long-term consequences for public health. One important and measurable impact is an increase in mortality and morbidity associated with extreme heat events, particularly in moderate climates. This special session describes research conducted by the University of Washington's Department of Environmental and Occupational Health Sciences (DEOHS) in collaboration with local and state public health departments. The research findings demonstrate a significant heat effect on health outcomes. These findings can be used by public health partners to develop communication strategies that engaged their communities (policy makers and the public), resulting in policy action.
During this special session, participants will learn about the relationship between extreme heat and mortality over the past 30 years, hospital admissions, and the demand for emergency medical services (EMS). Additionally, a method for mapping vulnerable heat-risk across the population will be described. Attendees will learn how local and state environmental public health practitioners are using local data to plan and implement mitigation and adaptation strategies in preparation for future extreme-heat events.
Preparing for Extreme Heat Events in Washington State: Historical Health Outcomes, Heat-Risk Mapping, and Public Health Policy Development
Tania Busch Isaksen, University of Washington; Miriam Calkins; Michael Yost; Brendon Haggerty; Jerrod Davis
This presentation describes the collaboration between UW Department of Environmental and Occupational Health Sciences and local and state public health officials to produce and use locally relevant data. During this presentation, participants will hear from 5 different speakers who will describe heat-health outcome data and heat-vulnerability mapping methods, as well as detail how data can be applied in the public health practice/policy setting.
Methods: Health outcome and meteorological data were analyzed using Poisson regression to describe relative risk and time series analyses of the historical relationship between mortality, hospital admissions, and the demand for emergency medical services (EMS) during extreme heat. Heat exposure was as assessed by the daily county-wide maximum humidex; humidex values were localized by census tract for spatial analysis of heat events. Health risk estimates were grouped by age and underlying cause. Vulnerable population data were combined with heat distribution data within census tracts to create heat-risk maps estimating proportion of cases per 1000 persons. Findings were translated and packaged to meet local environmental public health practitioners' communication needs.
Results: The risk of death and hospital admissions in King County increased by 10% and 2%, respectively, on a heat day compared to a non-heat day for all-ages, all-causes. When considering the intensity effect of heat, we found a 1.7% increase in mortality and a 1.6% increase in hospital admissions per degree increase in humidex above threshold. Of particular note, in the 45-64 year-old age group the risk of diabetic-related mortality increased by 78% on a heat day, with risk increasing 14.2% for each degree increase in humidex above threshold. The same age group also was found to be at increased risk of hospitalization for nephritis and nephrotic syndromes. Only age was found to increase vulnerability to adverse health outcomes. The 65+ census data was combined with regional heat distribution data to create an overall heat-risk map, by census tract. Results for emergency medical service calls are pending.
Data Use: Local health departments were active partners in shaping research questions and identifying the most effective ways of packaging results. Local practitioners used projected mortality and morbidity counts to plan and implement mitigation and adaptation strategies in preparation for health effects from extreme heat events. In this presentation we will review examples of public health responses to climate change, examining the role of public health agencies in various settings.
Floodplain Resilience: A Tool to Support Multi-objective Decision-making in Floodplains
Julie Morse, The Nature Conservancy
Puget Sound's major rivers and their floodplains support productive agriculture, sustain important fisheries, enable recreation and provide other functions essential to quality of life in the region. However, development and other activities in Puget Sound degrade floodplains threatening salmon populations, impacting water quality, and limiting the extent to which these areas can regulate flood waters and support other natural river functions. The variety of problems caused by the loss and degradation of floodplains has triggered responses from an array of stakeholders and interests, resulting in uncoordinated and often conflicting efforts to manage these critical areas. To address this challenge the Nature Conservancy launched Floodplains by Design, a collaborative effort to improve decision-making by providing information to align isolated objectives and integrate disconnected stakeholders. A key component of this strategy is the development of a decision support tool designed to provide data and data visualizations to guide floodplain management. Working with local partners in Snohomish County, we developed the Floodplain Resilience tool to incorporate information related to flood risk, salmon recovery and other objectives to better inform project prioritization and coordination among diverse partners. In this presentation, we will describe the design and content of the Floodplain Resilience tool and discuss the intended audiences and relevant decision-making applications.
Black Carbon and Dust Deposition on Seasonal Snow and Glaciers in Washington State: Implications for Water Resources
Susan Kaspari, Central Washington University; Ian Delaney, Central Washington University; McKenzie Skiles, Jet Propulsion Laboratory; Dan Pittenger, Central Washington University; Matt Jenkins, Central Washington University
In Washington State, meltwater from the seasonal snowpack and mountain glaciers provides an important source of water resources, however spring snowpack levels are declining and glaciers are retreating. While rising temperatures are a well-recognized factor leading to the reduction in the snowpack and glacier retreat, another potential cause of accelerated melt is the deposition of black carbon (BC) and dust onto the snow and glacier surfaces. BC (often referred to as soot) is a dark absorptive particle produced by the incomplete combustion of fossil and bio-fuels, and is second only to CO2 in its contribution to climate warming. In the atmosphere, BC absorbs light and causes atmospheric heating, whereas BC deposited on snow and ice affects climate and water resources by reducing the albedo (i.e. reflectivity) of snow and ice surfaces and accelerating snow and ice melt. Dust originates from both natural and anthropogenic sources, and also reduces snow and ice albedo.
Since 2010 we have collected snow and ice core samples from the seasonal snowpack and glaciers in Washington State to characterize the spatial and temporal variability of BC and dust deposited in Washington snow and glacier ice. BC concentrations in Washington's winter snowpack are relatively low, with BC concentrations increasing in spring and summer due to melt induced enrichment and increased dry deposition. BC induced melt may accelerate the timing of spring snowmelt at lower elevations, however BC induced melt is likely largest at relatively high elevations where the snowpack persists into the summer months when BC concentrations were observed to be highest. Preliminary results suggest that in general dust may be more effective than BC at reducing snow albedo because dust is present in much higher concentrations, with the exception of times of forest fire when BC deposition is greatest. A shallow ice core retrieved from Mt. Olympus demonstrated that BC deposition was a magnitude higher during the 2011 Big Hump forest fire, resulting in a threefold increase in the rate of change of river discharge due to glacier melt. An ice core from South Cascade Glacier spanning the 20th century also suggests that the highest BC concentrations are associated with forest fires. This research has implications for projected climate change, as forest fires are projected to increase and the seasonal snowpack is projected to decrease, both of which contribute to higher BC concentrations in the snowpack.
Riparian Climate-Corridors – Identifying Priority Areas for Conservation in a Changing Climate
Meade Krosby, University of Washington; Robert Norheim, University of Washington; David Theobald, Conservation Science Partners; Brad McRae, The Nature Conservancy
Protecting and restoring ecological connectivity is a leading climate adaptation strategy for biodiversity conservation, because species are expected to have difficulty tracking shifting climates across fragmented landscapes. Connectivity conservation is thus the focus of numerous large-scale climate adaptation initiatives, and is a primary strategy in many federal climate adaptation plans. This has led to a growing need for approaches that identify priority areas for connectivity conservation in a changing climate. Riparian areas have been identified as key targets for such efforts, because they span the climatic gradients species are likely to follow as they track shifting areas of climatic suitability, thereby providing natural corridors for climate-induced range shifts. Riparian areas also feature microclimates that are significantly cooler and more humid than immediately surrounding areas, and thus are also expected to provide microclimatic refugia from warming. Despite recognition of these values, rigorous methods to identify which riparian areas are most likely to facilitate range shifts and provide refugia are currently lacking. We completed a novel, fine-resolution analysis across the Pacific Northwest, USA, that identifies those potential riparian areas that span large temperature gradients, have high canopy cover, low solar insolation, low levels of human modification, and are relatively wide – characteristics that are expected to enhance their ability to accommodate climate-driven range shifts and provide microclimatic refugia. We found that riparian climate adaptation potential varies greatly across the region and is sensitive to scale of analysis. We therefore describe a multi-scale approach to implementing and interpreting our riparian climate-corridor model. The results of our analysis provide valuable information for guiding regional riparian management and climate adaptation efforts.
Climate Adaptation in Municipal Watershed Ecosystems
Amy LaBarge, Seattle Public Utilities
The City of Seattle's municipal watersheds are managed to provide high quality drinking water supply and additional ecosystem services, including habitat for threatened fish and wildlife species, flood regulation, carbon sequestration, cultural resources, and biological diversity, among others. The Cedar River Municipal Watershed is managed under a 50-year Habitat Conservation Plan (HCP) that provides regulatory certainty under the Endangered Species Act and commits Seattle Public Utilities (SPU) to mitigations that include instream flow agreements, fish passage improvements, and watershed protection and restoration activities. The South Fork Tolt River Municipal Watershed Plan provides similar protection and restoration goals, without documented threatened species. Climate change is projected to impact an array of management objectives, from decreasing snow pack effects on water supply, increasing extreme precipitation events and risk of landslides, and increasing moisture deficits elevating wildfire risk and other disturbances that could impact the structure and function of watershed ecosystems. These changes are likely to impact the provision of ecosystem services. SPU and advisory stakeholders are assessing whether current watershed management approaches are adequate to address projected climate-related impacts or if adjustments need to be made. Current approaches are intended to protect and improve watershed functions and resilience in meeting management objectives and include: managing the forest road network to handle extreme precipitation events and reduce the risk of sediment delivery to aquatic systems and water supply; conducting stream restoration to improve habitat for aquatic species; implementing forest restoration to improve habitat for terrestrial and riparian associated species, and to increase species composition; and monitoring long-term changes in forest and stream systems to determine management effectiveness. Climate change watershed management adaptation strategies include: long-term trend monitoring of terrestrial and aquatic ecosystems and fish and wildlife populations; documenting baseline conditions in special habitats, such as wetlands, to detect climate-related impacts; planting tree species that are better suited to warmer and drier growing conditions and confer higher resilience following disturbances; and potentially additional thinning in forest stands to maintain tree vigor and increase resistance to disturbances. SPU will investigate critical questions using regionally downscaled IPCC AR5 climate data, such as calculated Energy Release Component (ERC) that indicates doughtiness and fire severity, to better assess potential wildfire risk and develop comprehensive prevention and response strategies. Additional research questions include forest structure and snowpack dynamics, changes in plant community composition and impacts to cultural resources.
Salt Marsh Response to Dike Removal: Implications for Future Sea Level Rise
Martin Lafrenz, Portland State University; Catherine de Rivera, Portland State University; Sarah Eppley, Portland State University
The rapid flooding of ecosystems initiated by dike removal creates natural laboratories for examining potential effects of sea level rise (SLR) on saltmarsh ecosystems. We therefore started examining how ecosystem properties change over time in response to changed inundation. At Bandon Marsh National Wildlife Refuge, we established transects spanning from high marsh to mudflat in Ni-les'tun Marsh, which was recently re-watered following dike removal, and in a reference marsh, Bandon Marsh. At each 0.1 m decrease in elevation along each transect we collected soil, fauna, and vegetation data. While elevation, a proxy for tidal inundation length, was an excellent predictor of ecosystem properties, we still found a non-linear response to dike removal for most soil properties. Mudflats and low marsh areas are returning to a near-reference condition while high marsh conditions lag behind. Soil moisture and organic matter percentage are similar to the reference condition in the lower marsh, higher than the reference condition in the mid-marsh, and lower again in the high marsh. Salinity was slightly lower in the restored low marsh than in the reference marsh but much higher in the restored high marsh. The pH was significantly lower in the restored high marsh than its reference due to the development of acid sulfate soils; all ORP values were higher in the restored marsh, indicating incomplete reduction. Plants and animals had lower species richness and diversity in the dike-removal than the reference marsh, especially in the high marsh. The marshes differed in community composition. Percent above ground cover and percent root cover, both of which affect accretion rates, also are lower in Ni-les'tun than Bandon Marsh. Hence, the high marsh is responding slowly because of the low flood frequency while the daily inundation of the low marsh hastens a return to near reference conditions for many variables. Findings from historical dike removals suggest it may take as long as 50 years to establish typical high marsh vegetation communities. With SLR, then, we'd expect that areas being frequently inundated will adjust quickly but those areas being flooded occasionally may take decades to adjust. Here as elsewhere, we have noted an abrupt slope transition from low to the relatively flatter high marsh, which is particularly prominent in restored marshes. Hence, sea level rise just reaching the high marsh may quickly lead to a loss of the ecosystem services provided by the high marsh.
Forest Gaps and Data Gaps: Choosing Relevant Sites and Strategies for Collecting Actionable Data
Susan Dickerson-Lange, University of Washington and Rolf Gersonde, Seattle Public Utilities
Seattle Public Utilities and the University of Washington have led a 5-year collaborative research effort to quantify the influence of forest management actions, such as thinning and cutting canopy gaps, on snow processes in the Cedar River Municipal Watershed. This protected watershed is located the western slope of the Washington Cascades and provides 70% of the water supply to the greater Seattle Metropolitan Area. The collaboration has been driven by management-relevant goals to support forest restoration and enhance biodiversity, as well as science-relevant goals to use observational snow data to fill data gaps in forest-snow research. With both sets of goals in mind, we chose field sites to represent the forest structure and composition, as well as current management applications in the watershed. Among other results, we found that snowmelt is delayed up to two weeks in forest gaps relative to untreated 2nd growth forest in the maritime climate of the Cedar River Watershed, which differs from the bulk of snow-forest studies that were completed in colder climates.
Each product derived from the collaborative investigation was mutually beneficial, with implications for management decisions and continued research directions. In addition, our results from this initial investigation led to broader questions of applications within the wide range of climates seen in the Pacific Northwest. However, in order to scale up from an individual tree or experimental forest plot, to a watershed and a region, we need new strategies, more data, and expanded representation of management regimes. The next steps in this investigation will utilize an expanded regional snow-forest dataset, which will be provided by collaborators at Oregon State University and the University of Idaho, as well as citizen scientists. An advisory team will help direct the development of actionable products, including maps detailing the predicted influence of forest cover on snowmelt timing under present and projected climate conditions.
Evaluating Climate Change Effects on Wetlands with Field Surveys and/or Remote Sensing Techniques
Se-Yeun Lee, School of Environmental and Forest Sciences and Climate Impacts Group, University of Washington; Maureen E. Ryan, University of Washington & Simon Fraser University; Alan F. Hamlet, University of Notre Dame & Climate Impacts Group, University of Washington; Meghan Halabisky, University of Washington; Wendy J. Palen, Simon Fraser University; Joshua J. Lawler, University of Washington
Wetlands are thought to be among the most sensitive ecosystems to climate change via changes in temperature and precipitation and resulting changes in hydrology and water temperature. Understanding of how wetland hydrologic conditions have changed over time and space has the potential to help managers and decision-makers evaluate potential threats and identify management and policy needs. Field surveys provide critical but generally limited data on historical hydrologic patterns. Remote sensing (Landsat satellite imagery, high resolution aerial photos, and LiDAR) can be used to reconstruct wetland hydroperiods over a longer period and larger geographic area, but is limited by cloud cover and to the years for which aerial imagery are available (post-1970s). A hydrology model that physically simulates water and energy balance for given climatic conditions is able to evaluate change over longer periods (> 91 years). Combining observed data (via field surveys and/or remote sensing) with the physically based hydrology model is therefore a cost-effective approach to fill the temporal gaps over large extents (that differ in landscape type and size). We developed a regression based approach that relates observed data from field studies and remote sensing to simulated soil moistures (outputs from the hydrology model). The advantage of this approach is that it has widespread applicability regardless of existing monitoring data for relatively low cost. We have successfully reconstructed historical hydrologic changes for wetlands in Washington State and projected changes in wetland hydrology for climate change based on projected future changes in climate at two scales (individual ponds and landscapes). For individual ponds, climate change is projected to cause earlier drawdown, a more rapid recession rate, reduced water levels and longer dry season in summer corresponding to projected reduced snowpack, earlier snow melt and hotter and drier summers. Landscape maps show spatial patterns in the impacts of climate change on wetland hydrology. For energy-limited sites on the west side of the Cascades, warmer climate would significantly reduce water levels (up to 45%). In contrast, in water-limited sites on the east side of the Cascades, annual water levels show low sensitivity to warmer climate.
Extreme Weather Trends over the Pacific
Cliff Mass, University of Washington
A major concern regarding global warming is its potential impacts on regional extremes in wind, precipitation, and other parameters. Since some warming has already occurred over the region and globe, it is highly relevant to determine whether there have been any trends in Northwest extreme weather over the past 60-80 years, during which a reasonable distribution of observation locations have been available over this region. This presentation will examine the trends in the number of major weather events over the region, including windstorms, floods, heavy snow, atmospheric rivers, and the passage of intense midlatitude cyclones. The origin of any apparent trends will be discussed and insights into future trends, derived from examination of GCM output for the next century, will be reviewed.
Flooding in the Lower Snohomish: Sea Level Rise, River Flooding, and Inundation
Guillaume Mauger, University of Washington, Climate Impacts Group
Over the past decade, numerous climate change assessments have estimated changes in river flooding, sea level rise, and storm surge. Few, however, have quantified the joint impacts of both on future changes in flood risk. This talk will present a recently-completed assessment of changes in inundation projected for the lower Snohomish river basin. Building on previous work in the Skagit river basin (Hamman and Hamlet, 2012), we present changes in both the depth and area of inundation. Results are presented for recurrence intervals ranging from the 10- to 100-year flood, for both the middle and the end of the 21st century. The uncertainty in projections is quantified using considering high, middle, and low projections for both river flooding and sea level rise. Finally, we evaluate the relative importance of sea level rise and river flooding in driving changes in flood risk in the basin. Results from this work are incorporated into a decision support tool developed by The Nature Conservancy (TNC) to support multi-objective floodplain management by partners in the Snohomish river basins.
Evaluating Climate Change Vulnerability in the Pacific Northwest: Integrated Assessments of Potential Ecological Change in Three Case Study Landscapes
Julia L. Michalak, University of Washington; Joshua J. Lawler, University of Washington; John C. Withey, University of Washington; Michael J. Case, University of Washington; Sonia A. Hall, SAH Ecologia LLC; Theresa M. Nogeire, University of Washington
To create effective adaptation plans, land managers need an understanding of how climate change could alter ecological systems at the landscape scale. As research efforts continue to multiply, an increasingly wide variety of information can be used to assess potential changes. Such information includes projected shifts in climatic niche suitability, process-based projections of vegetation change, experimental and observational data on responses of species and systems to climate changes, and evaluations of species or system sensitivity to climate change based on natural history and/or expert opinion. Using multiple resources is important because each provides insight into potential changes for different processes and elements of the system at a range of spatial scales. Despite the theoretical importance of integrating multiple lines of evidence, to date, the majority of adaptation case studies have relied on general characterization of climate impacts, expert opinion, or projected changes from a single model—few have integrated many different sources of information.
Here we use several different types of information to evaluate climate vulnerability for three conservation priorities in three case study landscapes: Oregon white oak in the Willamette valley, Oregon, whitebark pine in southeastern Idaho, and sagebrush steppe on the Columbia Plateau, Washington. These three case studies illustrate how reviewing different types of information can provide a nuanced picture of change. We found general agreement among multiple lines of evidence that the Willamette Valley is likely to remain climatically suitable for Oregon white oak, while climatic suitability for whitebark pine is likely to decline in southeastern Idaho. In contrast, the future of sagebrush steppe on the Columbia Plateau appears more complex and uncertain with one set of models projecting stability, expansion and contraction depending on the location and climate scenario, and other models projecting complete elimination under some climate scenarios. For all three case studies, uncertainties remain and reviewing multiple sources of information was essential for identifying and understanding processes operating at different spatial scales that may lead to potential alternative future states. Despite these challenges, developing in-depth vulnerability analyses using multiple lines of evidence facilitated the development of a flexible and robust set of adaptation strategies.
The Value of Stored Water to Summertime Recreational Uses of Reservoirs in the Willamette River Basin
Kathleen Moore, CEOAS, Oregon State University; William Jaeger, Applied Economics, Oregon State University; Julia Jones, CEOAS, Oregon State University
The objective of this study is to empirically estimate the value of summertime recreational uses of reservoirs in the Willamette River Basin (WRB) as part of a larger study on optimal reservoir management under climatic and social change. The USACE operates a system of 13 reservoirs in the WRB to serve two main competing purposes: flood control during winter and spring, and storage of spring runoff for summertime recreation, irrigation, municipal supply, and instream flows. Optimal management of the reservoirs to maximize society's net benefits implies balancing the marginal benefits from storage against the marginal benefits from flood control. The choice of reservoir fill levels on any given date can be seen as weighing the expected benefits based on the probability distributions of anticipated future streamflows. This research estimates the marginal value of stored water for summertime (June-August) recreation based on a panel analysis of observed monthly visitation across 11 years and 9 reservoirs. This analysis was able to estimate the response in visitation to changes in reservoir fill level. These results were combined with published estimates of individuals' willingness-to-pay for this kind of recreation (Loomis 2005), to assess the value per acre-foot of water to recreation. The results of this model reflect how the recreational benefits of reservoir management are affected by lower fill levels. Low water levels resulted in declines in visitation in some but not all of the reservoirs. The largest effects occurred at the Fall Creek and Fern Ridge reservoirs, which showed reductions in visitation of 1-3% per foot drop in water level below maximum fill. The average effect across all reservoirs was a reduction of 0.65% per foot. The implicit value of water associated with this response ranges from $4-$19/af given historical visitation levels. In comparison the value of water per acre-foot to irrigated agriculture in the WRB has been estimated to average $17/af. Continuing research will quantify the marginal benefits associated with the other reservoir uses (stored water for summer agricultural and urban uses, and flood control) and investigate adjusting the reservoir rule curves to balance these benefits.
New Views of Regional Climate Change: The Advantages of a Super Ensemble
Philip Mote, Oregon Climate Change Research Institute (OCCRI); Sihan Li, OCCRI; David Rupp, OCCRI; Dean Vickers, OCCRI; Robert Mera, Union of Concerned Scientists; Myles Allen, Oxford University; Richard Jones, UK Met Office Hadley Centre
We describe a super ensemble of regional climate model simulations for the western US at 25 km resolution. Over 140,000 valid and complete one-year runs have been generated to date: about 130,000 for 1960-2009 using observed sea surface temperatures (SSTs) and nearly 10,000 for 2030-2049 using projected SSTs from a CMIP5 global model simulation. In order to explore and quantify sources of uncertainty and improve signal-to-noise ratio, ensemble members differ in initial conditions, model physics, and (potentially, for future runs) SSTs. This unprecedented confluence of high spatial resolution and large ensemble size leads to new understanding of the texture and robustness of climate change signals that have not previously been possible. Robust spatial patterns of changes in key climate variables emerge, in the energetics and hydrologic aspects of climate interactions in mountain regions, and in the behavior of extreme events which can be more accurately quantified with the superensemble.
Carbon Chemistry Observations in the Salish Sea: Evidence for Upwelling Influence and Implications of Sills for Ocean Acidification Effects
Jan Newton, University of Washington; Connie Sullivan, Puget Sound Institute; Richard Feely, NOAA PMEL
Understanding ocean acidification is important because the global increase in carbon dioxide can cause seawater to become undersaturated with respect to calcium carbonate bio-minerals (e.g., aragonite and calcite) that shelled organisms need to live. Community respiration at depth in marine environments, which produces carbon dioxide, causes deeper waters to be typically more corrosive than surface waters. Coastal upwelling areas, such as the coastal Pacific Ocean that feeds the Salish Sea, can be intermittently exposed to corrosive water conditions. Ocean acidification has increased the frequency, intensity, and duration of corrosive conditions off the Oregon shelf (Harris et al., 2013) and has been observed to be detectable in Puget Sound (Feely et al., 2010). We investigated the spatial and temporal expression at two stations in the central portion of the Salish Sea: one in San Juan Channel and one in the Strait of Juan de Fuca. We sampled seawater semi-weekly at four depths primarily during fall during 2011 and 2012, measuring temperature, salinity, oxygen, nutrients, dissolved inorganic carbon, and total alkalinity. Seawater density, pCO2, pH, and aragonite saturation were derived from these variables.
Carbon system variables showed variable distribution patterns with depth, location, over season, and interannually. Variation in pH and pCO2 primarily matched that of the hydrography, indicating the strong role of mixing in San Juan Channel and of stratification between estuarine (shallow outflowing) and oceanic (deep inflowing) waters in the Strait of Juan de Fuca. Also, a seasonal pattern was indicated, with evidence of upwelling and inflow of ocean-sourced waters with lower pH, higher pCO2, and lower aragonite saturation state in the fall. These waters, with more extreme values at depth in the Strait, were also evident at depth in the Channel. After this observation, subsequent weeks showed little variation over depth; however, the mean pH had shifted to lower values throughout the water column at both sites, consistent with mixing. These data can be interpreted to imply that deep oceanic intrusions of corrosive waters coming into the Salish Sea through the Strait of Juan de Fuca are mixed throughout the water column in locations like the San Juan Channel, where topographic features like sills and reefs, as well as strong tidal forcing, cause strong mixing. This effect, while decreasing the intensity of the corrosive signal at depth, can increase the spatial footprint of undersaturated waters to surface layers. Moreover, sills, which are common in the Salish Sea, can increase the residence time of these waters due to "re-fluxing" (Ebbesmeyer, 1980), meaning that mixing over sills retains some of the waters that would have been exported in the outflowing water through estuarine circulation.
Snow-Forest Interactions along an Elevation Gradient in the Oregon Cascades: Implications for Forest Management
Anne W. Nolin, Oregon State University; Travis Roth, Oregon State University
Snow in the Pacific Northwest, United States is highly sensitive to winter temperatures. During times of snow accumulation, storm temperature governs the partitioning of precipitation into rainfall and snowfall. During ablation, air temperature determines the rate of snowpack warming and melt. Snow accumulation and ablation in this region is also affected by land cover through the influence of forest canopy on snow interception and energy balance. In this research, we investigate how climate change and land cover change affect snow accumulation and ablation. Our Forest Elevation Snow Transect (ForEST) network is composed of six snow/climate monitoring stations at forested and open sites at low, mid- and high-elevations in the Oregon Cascades. Results from three years of measurements indicate that at elevations from 1100-1300 m where rain and snow can both occur, canopy interception decreases snow accumulation and is a significant proportion of total winter precipitation. In this warmer part of the seasonal snow zone, higher air temperatures and greater longwave radiation in the forest lead to earlier melt compared with higher elevation sites. Thus, at these lower elevations, snow in open areas persists longer than snow in the forest. At higher elevations (>1450 m), canopy interception is a relatively small proportion of total winter precipitation and forest temperatures are colder so net radiation remains negative until spring. Thus, at the higher elevation sites, the snowpack lasts longer in the forested sites than in the open areas. These results indicate that snow retention depends on storm temperature, canopy interception, and energy balance. The impacts of climate change must be considered as the rain-snow transition zone rises in elevation. Moreover, the impacts of land management and land cover change must be considered as forest disturbances such as fire and insect damage alter canopy interception, net radiation, and ultimately snowpack retention.
Preparing Seattle for Climate Change
Valerie Pacino, City of Seattle
Planning for climate change across the complex functions of a city creates not only interesting opportunities but also challenges in how planning is executed. Like most cities, the City of Seattle is responsible for land use regulation and planning, transportation infrastructure and services, parks and recreation, human services, solid waste etc. Uniquely, Seattle also owns its water supply resources and electricity system. The levels of expertise in understanding climate impacts and how to use climate projections in planning varies widely across the city. Seattle's electric, water, and stormwater utilities, as rate funded utilities whose resources are highly climate dependent, have been at the leading edge of planning for climate impacts and have a high level of staff expertise. Other departments have begun considering projected climate impacts on their infrastructure, operations, and services and are leveraging the work and planning methods of the utilities. The City's Office of Sustainability & Environment is responsible for planning for climate mitigation and adaptation across city departments and is leading development of a citywide climate impacts preparedness strategy. Challenges in developing a citywide strategy include aligning planning methods across departments with different levels of resources and in-house expertise to create a comprehensive citywide strategy and fostering consistency balanced with the necessary flexibility to be effective across a diverse array of functions. This presentation will focus on how Seattle is aligning these efforts and leveraging the advanced work already underway in the utilities to inform a citywide strategy. Topics which will be discussed include how departments are starting the adaptation planning process despite limited resources, City processes and plans are being considered for "mainstreaming" climate change considerations, and considering vulnerable populations in resilience planning.
Climate Change Impacts on Glacier Melt, Stream Temperature, and Discharge in the Headwaters of the Nooksack River, WA
Mauri Pelto, Nichols College, Dudley, MA; Oliver Grah, Nooksack Indian Tribe; Jewzra Beaulieu, Nooksack Indian Tribe
Glaciers comprise the headwaters of the Nooksack River and are a critical source of summer discharge and greatly influence summer stream temperatures. There are nine species of salmon in the watershed that the Nooksack Indian Tribe depends on for cultural, subsistence, and economic uses. Climate change is an additional new threat to salmon that has caused and will continue to cause an increase in winter flow, earlier snowmelt, decreased summer baseflow, and increased summer water temperatures. Climate change combined with the adverse effects of legacy impacts and habitat alteration will increase the frequency of conditions that exceed salmon tolerance levels. This presentation will focus on the changing impact of glaciers on streamflow and the evolving water temperature threat.
Discharge and temperature responses of the unglaciated South Fork Nooksack River (SF), and the glaciated Middle Fork (MF) and North Fork (NF) Nooksack River are compared during 12 warm weather events occurring in August or September in 2009, 2010, 2012 and 2013. During each of these events ablation was measured on glaciers in the basin. For discharge, a 10% increase is set as the key threshold for significant response to each warm weather event. For the NF 10 of 12 events exceeded the limit, in the MF 4 of 12 events had a significant response and for the SF none of the 12 events led to a 10% flow increase. It is apparent that warm weather events increase glacier melt thus enhancing flow in the NF, and in a basin without glacier runoff the hydrologic system consistently experiences reduced discharge.
For water temperature, an increase of 2° C is the threshold of significance used for response to warm weather events. In each the NF and MF, 2 of 12 events exceeded this threshold, and for the SF 12 of 12 events exceeded this threshold. Warm weather events consistently generate a significant increase in stream water temperature only in the non-glaciated South Fork Basin. During 6 of these 12 warm events, runoff measurements below Sholes Glacier and ablation measurements on Sholes and Easton Glacier indicate daily ablation ranging from 0.05-0.06 md-1, which for the NF currently yields 9.5-11 m3s-1. This is 40-46% of the August mean discharge of 24 m3s-1. Increased glacier discharge largely offset the impact of increased air temperature on stream water temperature during the warm weather events.
Assessing the Vulnerability of Wastewater Facilities to Sea-Level Rise
John Phillips, King County DNRP WTD; Shaun O'Neil, King County DNRP WTD
Sea-level rise poses a direct and measureable threat to low lying infrastructure in tidally influenced areas. Since 1960, the mean sea-level in Puget Sound has increased 4.24 inches measured at the Seattle tide-gauge. In the most likely sea-level rise scenario, it is predicted to rise another 6 inches by 2030 and 13 inches by 2100 due to climate change. Storm surges have already and are expected to increase tide heights even more.
The King County Wastewater Treatment Division, which owns and operates the regional wastewater system that serves 1.5 million people in the Seattle area within Central Puget Sound, is already experiencing the effects of saltwater intrusion in its system during extreme high tides. To assess the potential effects of projected sea level rise, the division undertook a vulnerability assessment of its facilities. The assessment used the most recent sea-level rise predictions from the University of Washington Climate Impacts Group for the region, historical storm surge data, current tide gauge information, and facility elevations and features to predict the effects of four predicted sea-level and historic storm surge scenarios. The methodology relied on in-situ data collection, observations, facility inspections and geographic information systems (GIS) analytical techniques applied to spatial data.
The resulting inventory of vulnerable facilities provides decision-makers with information they can use to determine the acceptable risk associated with sea-level rise. This measure of risk can be used in conjunction with other planning variables, such as capacity and condition, when determining how future capital expenditures will be allocated towards addressing vulnerabilities in addition to capacity and condition through existing capital programs. Other utilities can easily adapt the tool developed for the assessment for evaluating the vulnerability of their systems to sea-level rise in a cost-effective way.
Elevational Dependence of Climate Variability and Trends in British Columbia's Cariboo Mountains, 1950-2010
Aseem Raj Sharma, Natural Resources and Environment Studies, University of Northern British Columbia, PG, BC; Déry, Stephen, J., Natural Resources and Environment Studies (NRES), University of Northern British Columbia, PG, BC; Cannon, Alex ,Pacific Climate Impacts Consortium, University of Victoria, Victoria, BC
Pristine mountain environments are more sensitive to global-scale climate change than most other land surfaces. Previous studies reveal inconsistent findings on the elevational dependency of the warming rate in mountainous terrain. The paucity of observation-based data in mountainous regions, limitations of climate models to capture the complex mountain topography and high uncertainties on climate model outputs make the understanding of climate variations and trends in these regions uncertain. In this study, we explore the elevational dependence of climate variables (air temperature and precipitation) and their trends in the Cariboo Mountains of British Columbia, Canada over six decades. This study incorporates in situ observations from several governmental agencies along with a newly developed, high resolution gridded dataset of climate variables for western Canada. The non-parametric Mann-Kendall test was performed for evaluation of long-term trends and their statistical significance. The minimum temperature trend shows significant amplified warming at higher elevations of the Cariboo Mountains, but the maximum temperature trend shows an opposite pattern. Precipitation does not show any significant trend across the domain area. The presentation will end with a discussion about the possible physical mechanisms for such warming trends in the Cariboo Mountains and the potential impacts of these changes on the endangered mountain caribou and water resources of the area.
From Glaciers to Grids: Preparing for Climate Change at Seattle City Light
Crystal Raymond, Seattle City Light
In 2013, Seattle City Light expanded efforts to prepare for climate change with a 3-year initiative in the utility's Strategic Plan. The initiative includes research to better understand the impacts of climate change on infrastructure and operations and the development of adaptation strategies. Seattle City Light (SCL) is a public utility supplying electricity to over 400,000 customers in the Seattle area. SCL's source of electricity is primarily hydropower (90%), 50% of which is generated at two hydroelectric projects owned and operated by the utility. Both hydroelectric projects are located in snow-dominated basins (the Skagit and Pend Oreille) and partially depend on snowpack for water storage to augment reservoirs. Warming temperatures are expected to reduce snowpack and shift these basins to mixed-rain-and-snow basins by the end of the 21st century. Associated changes in the amount and timing of streamflow will challenge the utility's ability to balance reservoir operations for the multiple objectives of power generation, flood control, recreation, and instream flows for fish. SCL is expanding its analysis of the impacts of climate change on streamflows and reservoir operations by collaborating with the climate science community. The utility is working with National Park Service and University of Washington researchers to model changes in streamflow caused by glacier recession in the Skgait basin. This information will help the utility to adapt instream flow management for the protection of cold-water fish. In addition to hydroelectric projects, SCL owns and manages miles of transmission and distribution lines making up the power grid that delivers electricity to customers. The transmission and distribution system passes through rural forested areas, along unregulated rivers, and over steep rugged topography. SCL is assessing the vulnerability of this system to direct changes in climate (extreme heat, wind, and lightning) and associated impacts related to changes in flood regimes and landslide frequency. SCL owns and manages two communities in the North Cascades that are surrounded by the Ross Lake National Recreation Area. The utility is assessing the vulnerability of these areas to increasing fire hazard and exploring strategies to increase preparedness. These adaptation planning efforts are coordinated with other departments in the city of Seattle as part of a city-wide process to prepare for climate change. Through these efforts, we are learning approaches and "entry points" for incorporating climate change adaptation into current plans and processes with the long-term goal of creating a city that is resilient to climate change.
Glacial Record of Climate Change in Pacific Northwest
John Riedel, NPS
Pacific Northwest glaciers left clear evidence of past climate change at all timescales. Glacially buried forests at multiple sites indicate that modern glaciers have retreated to positions not seen since the mid-Holocene. Gradual summer cooling at this latitude caused by change in axial tilt led to ever larger, though cyclic, glacial advances for the past 7,000 years. As a result, most glaciers in this region reached their largest size in the last 10,000 years between 1500 and 1900 A.D. in the Little Ice Age (LIA). The buried forest record also suggests that periodic glacier advances at millennial and shorter timescales may be related to variability in solar output and the condition of the Pacific Ocean. Regional glacier advances lasting for several centuries (i.e. Garibaldi, Burroughs-Tiedemann, First Millennium A.D., and LIA) were separated by periods of warmer temperatures that led to glacier recession and forest growth on lateral moraines. During at least the LIA, maximum glacier advances occurred during the low solar activity phases of the ~200 year Suess cycle (i.e. Sporer, Maunder, Dalton, or Damon minimums). Recent regional glacier mass balance measurements and temperature reconstructions indicate that glacial activity during and since the LIA were also related to conditions of the northern and equatorial Pacific Ocean (PDO and ENSO). Glacial mass balance anomalies fluctuated at 60-80 year intervals for the past several centuries, similar to long-term temperature variability in the northeast Pacific. Since the late1950s, 4-7 year long periods of positive cumulative mass balance punctuated glacier retreat, but were not enough to reverse a rapid decline in glacier volume.
Wetlands and Climate Adaptation in the National Parks
Regina Rochefort and Barbara Samora, National Park Service
The Organic Act of 1916 directed the National Park Service (NPS) to protect its natural and cultural resources "by such manner and by such means as will leave them unimpaired for future generations." Implicit within this vision was the belief that we could protect ecological integrity and ecosystem function by limiting "human dominance" over our landscapes. The pervasive and rapid nature of climate change has presented risks to park resources and challenges to how we can steward NPS resources for continuous change, that is not yet fully understood, in order to preserve ecological integrity. In 2010, the NPS published the Climate Change Response Strategy which outlined four courses of action: science, adaptation, mitigation, and communication. This document was followed by the NPS Climate Change Action Plan which provided further direction on adapting park management to changing climates. In 2011, the NPS and US Forest Service initiated the North Cascadia Adaptation Partnership (NCAP) to conduct vulnerability assessments and develop adaptation strategies on sensitive resources in the Cascades. Wetlands, and in particular high-elevation wetlands, were identified as one of our most sensitive resources. Since the NCAP workshop, we have worked to increase our understanding of these ecosystems, promote research to project the speed and magnitude of change, and initiated discussions regarding how our fundamental management policies may require significant change in the future.
Developing a Time of Emergence Approach to Sea-Level Rise
James Rufo-Hill, Seattle Public Utilities
The signal of climate change is emerging against a background noise of natural variability. The concept of time of emergence (ToE), defined by measuring change of a signal or impact versus the standard deviation of a control, is itself emerging in literature. Of all known climate change impacts, sea-level rise (SLR) lends itself well to ToE approaches because of its relative certainty. That is, sea-levels are essentially moving in one direction only and the key questions are simply how high and when? The majority of SLR projections to date have focused on how high sea-levels will rise by particular dates, usually 2050 and 2100. While this approach is instructive for some audiences, adaptation planners must often consider time horizons or design lives of varying and independent lengths. Drawing upon lessons learned using the former method, an approach to planning for SLR that considers ToE has been developed by Seattle Public Utilities.
Managing for Wetlands Resilience at the US Fish & Wildlife Service
Mike Rule, USFWS
Managers within the US Fish and Wildlife Service National Reserve System face complex on-the-ground challenges in managing wetlands under climate change. This talk addresses the challenges, opportunities, needs from the research community, and current efforts to manage for wetlands resilience in the face of climate change.
New views on Future Northwest Climate
David Rupp, Oregon State University
A total of 20 state-of-the-art global climate models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) considering two Representative Concentration Pathways (RCPs) have been statistically downscaled using the Multivariate Adaptive Constructed Analogs (MACA) method for a suite of daily meteorological variables over the contiguous US and the Canadian Columbia River basin. From this dataset, we calculate temporal trends and spatial patterns of change over the Pacific Northwest (PNW) of means and extremes (e.g. 99th percentiles) of precipitation, temperature (and diurnal temperature range), wind speed, incoming short-wave radiation, and humidity. Although the variables are statistically downscaled to approximately a 7 km horizontal resolution, the over-riding spatial patterns are still largely driven by the dynamics of the GCMs, which operate at resolutions of approximately 200 km (varying among GCMs). We, therefore, explore the consistencies and differences of some of the spatial patterns of change with those produced by a set of regional dynamically downscaled datasets that directly simulate atmospheric dynamics at finer resolutions and therefore explicitly incorporate the influence of regionally topography. These latter datasets include climate simulations from the North American Regional Climate Change Assessment Program (NARCCAP; 50 km), western US Climateprediction.net (CPDN; 25 km), and the USGS Regional Climate Downscaling Project (USGS RegCLIM; 15 km).
Wetlands and Climate Change: Bridging the Gaps in Science and on-the-ground Adaptation
Maureen Ryan and Meghan Halabisky, University of Washington
Wetlands are universally recognized as globally important ecosystems that serve a wide range of functions from wildlife provisioning to water storage and filtration to nutrient cycling and carbon sequestration. The shortage of empirical data on wetland dynamics, coupled with the inherent complexities of studying wetlands has created challenges for the development of models of climate impacts to wetlands, and therefore for on-the-ground conservation and management of wetlands in the face of climate change. We address the ways in which our team is addressing these challenges through field studies, remote-sensing methods, and new modeling approaches developed in collaboration with wetlands and land managers in the Pacific Northwest.
Extreme Precipitation in the Northwest: Implications for the Snohomish River Basin
Eric Salathé, UW Climate Impacts Group
Significant work has been done in projecting scenarios of future climate in the Pacific Northwest using statistical downscaling methods and hydrologic models. However, intense short-term weather events produce some of the most important environmental hazards and present significant challenges to land managers, disaster response agencies, and land owners. For the Northwest, events of particular concern include heavy precipitation and flooding both in the winter and summer, heat waves, storms with high-wind and lightning, and drought. Global climate model results suggest substantial changes in the geographical and seasonal distribution of a broad range of extreme events with climate change. These events depend on processes that are not well represented either by global models or the observing network. Thus, it is not clear whether statistical methods can adequately represent changes in these processes in a future climate. An emerging tool, regional climate models can explicitly represent the mesoscale processes that control the timing, intensity, and extent of extreme events and can produce local climate responses quite different from those indicated by global models combined with statistical downscaling. This presentation will discuss recent research on the emergence of extreme events as indicated in both global climate models, statistical downscaling, and regional models. This talk will attempt to clarify the differences in climate information generated by global models and various downscaling approaches for extreme events and how that information can be used to inform management decisions.
Howard Hanson Dam, Green River, Washington, Climate Change Impacts and Adaptation Study
Kevin P. Shaffer, P.E., U.S. Army Corps of Engineers; Lawrence J. Schick, U.S. Army Corps of Engineers; Kristian E.B. Mickelson, P.E., U.S. Army Corps of Engineers
The study was an investigation of potential climate change impacts to the Green River basin, Washington, and an exploration of possible water management vulnerabilities and adaptations at Howard Hanson Dam. The dam is a multipurpose project owned by the U.S. Army Corps of Engineers and is operated for flood risk management, fisheries management, and municipal water supply for the City of Tacoma. Historically, flood season on the Green River has occurred between November and February and the refill of the reservoir has occurred between late February and June. The primary concern of this study was to investigate the possibility of overlapping flood and refill seasons in the future.
Simulated hydrology for the study covered a 30-year historical time period and two future time periods, extending to 2069. The ECHAM5 A1B Global Climate Model was dynamically downscaled using the Weather Research and Forecasting (WRF) model to create the forcing datasets. Both the fine-scale Distributed Hydrologic Soil Vegetation Model (DHSVM) and the macro-scale Variable Infiltration Capacity (VIC) model were utilized for hydrologic modeling. The future hydrologic data exhibited generally wetter winters and drier springs.
We modeled reservoir regulation using the simulated hydrology to assess potential vulnerabilities in the Hanson Dam water control plan. Regulated flows downstream at Auburn, Washington, exhibited higher peak flows and more instances of flooding in the future simulations. The timing of flooding in the Green River basin did not appear to shift significantly in the future time periods. While simulated spring floods were slightly larger in the future time periods, they were easily managed using current reservoir operations. More significantly, the future simulated spring flows were generally lower than historical flows and required earlier refill completion dates for conservation storage. Conservation refill success was not impaired but the earlier conservation storage, combined with overall lower spring flows, appeared to hinder successful refill of municipal storage in the future. The reservoir simulation was adapted to allow the City of Tacoma to store water beginning 20 days earlier each year, which resulted in increased refill success and no apparent hindrances to flood risk management.
The scope of this study was limited to one potential climate change scenario. The results suggest that the current water control plan at Hanson Dam is somewhat resilient to climatic shifts and that reservoir regulation could be adapted to accommodate climate changes to the Green River Basin.
How Much Has Snowpack Declined in the Western USA?
Darrin J. Sharp, Oregon Climate Change Research Institute, Oregon State University; Philip W. Mote, Oregon Climate Change Research Institute, Oregon State University; Dennis P. Lettenmaier, Civil and Environmental Engineering, University of Washington
Mountain snowpack in the western USA is a key component of the hydrologic cycle. Water is stored in the snowpack over the winter, and then released in the spring and early summer as it melts; much of the summer streamflow in the west originates as snowmelt. As a result, knowledge of trends in April 1 Snow Water Equivalent (SWE) in this region is critically important to water resources management, fire preparedness, and other activities. Analyses published a decade ago indicated a widespread decline in April 1 SWE over the last half of the 20th century. This project updates these earlier results with data through 2013 and extends the analysis in important ways. Observations from both the Natural Resources Conservation Service and the California Department of Water Resources were included and analyzed for statistical significance. In addition, the Variable Infiltration Capacity (VIC) hydrological model, driven by historical climate data, was employed as another method of estimating trends in snowpack over this period. For the 701 stations included in the observational data set, there was a mean decline in April 1 SWE of almost 14% over the western USA during the period 1955-2013. Of these 701 stations, 135 showed a statistically significant decrease in SWE while only 4 showed a statistically significant increase. The VIC results allow estimates of area-averaged declines. Despite a number of fairly snowy spring seasons in the most recent decade of data newly added to this analysis, and using a starting point after the fairly snowy 1945-55 period, the Northwest's snowpack is still clearly in decline.
Rainfall-Triggered Landslides in the PNW: Future Hazards and Risks
Ronda Strauch, University of Washington; Erkan Istanbulluoglu, University of Washington
Landsliding is a global phenomenon. Pacific Northwest represents a natural laboratory for studying landslides with its high precipitation, steep topography, glacially reworked soils, and regime of natural and anthropogenic disturbances on forest vegetation. In this study, we developed and tested a landslide susceptibility mapping approach that combines a static and a dynamic susceptibility mapping methodologies in the North Cascades mountains of Washington. Intrinsic site characteristics were calibrated with known landslide locations to model the static landslide susceptibility. This static index demonstrates the variable influence of different attributes of topography, land use-land cover, and substrate. A dynamic susceptibility was determined using a probabilistic slope stability model supplied with subsurface flow recharge and surface runoff generated from a space-time storm model simulated to match current storm statistics. Summer thunderstorms were the initial focus of this research. Combining the static and dynamic susceptibility generated a gridded relative slope stability index. This current condition index was compared to a future stability index created by adjusting the dynamic susceptibility using projected future precipitation regime. This comparison provided insight into how climate change may alter rainfall-triggered landslides in the future, particularly in the summer. To understand the implications of changes in slope stability, we overlaid a discretized road and trail network on the future slope stability grid. Results demonstrate spatial-temporal variability in transportation risks from landslides and provide information for adaptation planning that addresses both the human and natural dimensions of climate change and variability.
Climate-linked Mechanisms Driving Spatial and Temporal Variation in Eelgrass (Zostera marina L.) Growth and Assemblage Structure in Pacific Northwest estuaries
Ronald M. Thom, Marine Sciences Laboratory, Pacific Northwest National Laboratory; Susan L. Southard, Marine Sciences Laboratory, Pacific Northwest National Laboratory; Amy B. Borde, Marine Sciences Laboratory, Pacific Northwest National Laboratory
Using laboratory experiments on temperature and leaf metabolism, and field data sets from Washington, between 1991 and 2013, we developed lines of evidence showing that variations in water temperature, mean sea level, and desiccation stress appear to drive spatial and temporal variations in eelgrass (Zostera marina). Variations in the Oceanic Niño Index (ONI) and mean sea level (MSL), especially during the strong 1997−2001 El Niño-La Niña event, corresponded with variations in leaf growth rate of an intertidal population. Field studies suggested that this variation was associated with both desiccation period and temperature. Subtidal eelgrass shoot density recorded annually over a 10-year period was lowest during the warm and cool extremes of sea surface temperature. These periods corresponded to the extremes in the ONI. Variations in density of a very low intertidal population in a turbid estuary were explained by both variations in temperature and light reaching the plants during periods of higher MSL. These results show complex interactions between water-level variation, temperature and light as mechanisms regulating variation in eelgrass, which complicates the ability to predict the effects of climate change on this important resource. Because of the extensive global distribution of eelgrass, its tractability for study, and its responsiveness to climate, this and other seagrass species should be considered useful indicators of the effects of climate variation and change on marine and estuarine ecosystems.
Climate Change and Wind Intensification in Coastal Upwelling Ecosystems
Sarah Ann Thompson, Farallon Institute for Advanced Ecosystem Research and Climate Impacts Group - UW; William J. Sydeman, Farallon Institute for Advanced Ecosystem Research; Marisol García-Reyes, Farallon Institute for Advanced Ecosystem; Research David S. Schoeman, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia; Ryan R. Rykaczewski, University of South Carolina; Bryan A. Black, University of Texas; Steven J. Bograd, Southwest Fisheries Science Center, NOAA
Eastern Boundary Current Systems (EBCS) are productive coastal areas that thrive due to nutrient input from upwelling. Coastal upwelling, driven by alongshore winds, moves surface water offshore while cycling cold, nutrient-rich water from the depths to the photic zone. In 1990, Andrew Bakun proposed that the increase in greenhouse gases behind anthropogenic climate change would lead to intensification of upwelling-favorable winds in the world's EBCS. The proposed mechanism is that continental warming will cause steeper temperature and pressure gradients between the oceans and continents, strengthening the alongshore winds. We conducted a meta-analysis of 22 studies to examine whether wind trends in EBCS support this hypothesis. Our results showed general support for this hypothesis with increasing wind trends in three of the five EBCS worldwide. We also found that the degree of wind intensification was stronger with increased latitude, which is consistent with the warming pattern associated with climate change.
Salt Marsh Management and the Coastal Ecosystem Response to Climate Change: A bottom-up Approach for Informing Adaptation Strategies
Karen Thorne, USGS Western Ecological Research Center; Roy Lowe, U.S. Fish and Wildlife Service
In the Pacific Northwest, climate change effects on coastal ecosystems will include rising sea levels and increasing extreme storm events. Sea levels are projected to increase up to 143 cm by 2100 and storms are expected to increase in frequency and magnitude, both threatening the persistence of ecosystems at the land-sea interface including estuaries, mud flats, and salt marshes. Land managers are tasked with conserving these coastal ecosystems and the species dependent upon them. However, climate adaptation plans are challenging for managers to develop, primarily because detailed baseline data of current conditions, relationships among linked habitats, and models that project future conditions at a local scale are often lacking. For example, the U. S. Fish and Wildlife Service, Oregon Coast National Wildlife Refuge Complex spans more than 500 km of coastline and includes three marine and three estuarine refuges. Estuarine refuges at Nestucca Bay, Siletz Bay, and Bandon Marsh differ in their geographic settings and habitat composition. Substantial variation exists among these areas including differences in elevations, tidal range, sediment availability and deposition, and plant species composition that will alter the response and resilience of habitats to climate change threats. To provide science support for climate adaptation, the Northwest Climate Science Center and North Pacific Landscape Conservation Cooperative provided funding to the U. S. Geological Survey to initiate a Coastal Ecosystem Response to Climate Change (CERCC) program. Working with Oregon State University and the University of California at Davis and Los Angeles, CERCC provides databases and models suitable for informing management plans at a local level. Following a bottom-up approach at Siletz and Bandon, we used Real Time Kinematic Global Position System units to survey elevations and create digital elevation maps, installed stations to monitor tidal levels, storm events, and salinity, and conducted vegetation plots to assess plant communities. We used radioisotope dating from sediment cores to calibrate a Wetland Accretion Response Model for Ecosystem Resilience (WARMER) that projects marsh elevations under sea-level rise scenarios through 2100. Researchers are working together with managers to organize "roadshow" workshops to present these findings to estuarine land managers, discussing local results in the context of regional variation observed along the Pacific coast gradient. We will also facilitate focused, in-depth, one-on-one discussions to identify manager- and site-specific science needs. Finally, we will discuss how these climate science results may be incorporated into actionable habitat conservation management plans and adaptation strategies.
Climate Change Effects and Adaptation Approaches for Terrestrial Ecosystems, Habitats, and Species in Pacific North America
Patricia Tillmann, National Wildlife Federation; Patty Glick, National Wildlife Federation
With the growing number of scientific papers on climate change and continued interest among resource managers and conservationists to account for climate change in their work, there is a need to summarize climate change information for key geographies and ecosystems. In response to this need, we produced an extensive "state of the science" compilation of climate change effects and adaptation approaches specific to the terrestrial ecosystems of the North Pacific Landscape Conservation Cooperative (NPLCC) geography. These ecosystems extend from southern Alaska to northern California and include much of the Pacific Northwest.
We draw from peer-reviewed studies and synthesis reports, government reports, and publications from non-governmental organizations to summarize climate change and ecological literature on historical baselines, observed trends, future projections, policy and management options, and knowledge gaps. We begin with climate impacts – altered hydrology, growing seasons, freeze/thaw patterns, and disturbance regimes – then describe implications for ecological processes and ecosystem services, changes in terrestrial habitat status, distribution and composition, and finally, implications for mammals, birds, invertebrates, lichens, mosses, and interactions with invasive and non-native species. Much of the habitat focus is on temperate rainforests, as they dominate the region, but the region's high-elevation, savanna, and prairie ecosystems are also covered in detail. Climate-smart policy and management options respond to the impacts described and range from supporting science-management partnerships to taking action on-the-ground. This compilation is being used by land and resource managers in the NPLCC region as a reference document and has also found broader applicability in federal agencies around the U.S.
Selecting Climate Change Scenarios Using Impact-Relevant Sensitivities
Julie A. Vano, Oregon State University; David E. Rupp, Oregon State University; John B. Kim, U.S. Forest Service; Philip W. Mote, Oregon State University
In climate impact studies, there is often the need to select a small number of global climate model simulations for detailed investigation. Ideally, this sub-set would contain models that are both (1) good performers, meaning they adequately simulate historical climate, providing plausible results for the region of interest and (2) span the range of possible futures for the variable/s that are most important to the impact under investigation. We demonstrate an approach that incorporates both concepts to qualitatively select a sub-set of global climate models. To capture how an ecosystem process responds to projected future changes, we methodically sample, using a simple sensitivity analysis, how an impact (e.g., streamflow magnitude, vegetation carbon) respond locally to projected regional temperature and precipitation changes. We demonstrate this technique over the Pacific Northwest, focusing on impacts related to streamflow magnitudes in critical seasons for water management in the Willamette, Yakima, and Upper Columbia River basins and annual vegetation carbon in ecoregion sections of the Oregon and Washington Coast, Western Cascades, and Columbia Basin.
Sea Level Rise Adaptation: the Science-Policy Interface in British Columbia
Thomas White, British Columbia Ministry of Transportation and Infrastructure
Uncertainty around how much sea levels will rise, when and what impacts this will have on any given community make adaptation a challenge for coastal communities in British Columbia. The government of British Columbia has developed a suite of science-informed information and tools to help coastal managers respond to this new challenge by pursuing adaptation and building community resilience. This talk will provide an overview of the science-policy interface related to sea level rise adaptation in British Columbia, progress to date, and outstanding information and policy needs. Its objective is to provide context for other presentations in a special session, and to identify some of the challenges in translating science to policy in a government context.
The Sound Transit Climate Risk Reduction Project
Lara Whitely Binder, UW Climate Impacts Group; Amy Shatzkin, Sound Transit; Carol Lee Roalkvam, Washington State Department of Transportation; Ingrid Tohver, UW Climate Impacts Group; Amy Snover, UW Climate Impacts Group
The Sound Transit Climate Risk Reduction Project was a first-ever assessment of how climate change may affect Sound Transit services in the Central Puget Sound region. The project also identified agency-specific options for adapting to projected impacts and explored opportunities for integrating climate change considerations into agency decision making processes. Project partners included Sound Transit, the University of Washington Climate Impacts Group, and the Washington State Department of Transportation. Funding for the project was provided by the Federal Transit Administration (FTA).
The Sound Transit Climate Risk Reduction Project drew heavily on published climate impacts research, existing asset mapping and inventories, and structured workgroup activities with technical agency staff and senior managers to identify climate-related hazards and risks. Where possible, the project sought to identify specific climate-sensitive thresholds at which point important infrastructure, operations, and planning assumptions become stressed or fail. This presentation will summarize relevant details on how the project was conducted, key findings from the project, and lessons learned.
Climate Change Impacts: An "Apptitude" for Resilience
John Yaist, Esri
In June 2013 as part of The Climate Action Plan, President Obama announced the Climate Data Initiative, an effort to encourage tech innovators to use data about climate change risks and impacts in compelling ways to help citizens, businesses, and communities makes smart choices in the face of climate change. Esri, the world leader in GIS software, wanted to help the President reach this goal by encouraging developers to build game changing apps that promote climate resilience by hosting the Climate Resilience App Challenge 2014. This talk will discuss the challenge logistics, including organization site, communication methods with participants, and judging process. The talk will also cover the challenge winners, top submissions, and patterns revealed through the app submissions. The talk will conclude with thoughts on the role these apps and apps in general might play in decision making and plans for future ideas to encourage innovation.
Questions? Contact Lara Whitely Binder, Climate Impacts Group, firstname.lastname@example.org