Climate Change Impacts on the Puget Sound Region Lara Whitely Binder Climate Impacts Group Center for Science in the Earth System University of Washington April 2, 2012

Collective expertise includes : Adaptation planning and outreach Working since 1995 to: Produce science useful to (and used by!) the decision making community Increase regional resilience to climate variability and change An integrated research team studying the impacts of climate variability and climate change in the PNW and western US The Climate Impacts Group Downscaling global climate model projections Macro and fine-scale hydrologic modeling Impacts assessments for water resources, terrestrial and aquatic ecosystems Adaptation planning and outreach

M&I Water Supply Flood Management Environmental Protection Energy Supply Water Quality Public Health Stormwater Management Natural Areas Mngmt Climate Affects Important Local Government Services and Functions Economic Development

Samish Island, Skagit County, Jan 2009 Riffe Lake, near Morton, WA, Jan 24, landslide damage – Washington Dept. of Ecology

John Tyndall discovers that some gases block infrared radiation. He suggests that changes in the concentration of the gases could bring climate change. The Scientific Basis of Climate Change (con’t)

Svante Arrhenius publishes first calculation of global warming from human emissions of CO 2. Arrhenius projects that doubling the CO 2 in the atmosphere would raise global temp some 5-6°C (9- 11°F)

1938 – Guy Callendar publishes The Artificial Production of Carbon Dioxide and its Influence on Temperature. Links upward trends in early 20 th century global temperatures to increasing concentrations of atmospheric CO2 and fossil fuel combustion The Scientific Basis of Climate Change (con’t)

+35% Figure source: IPCC 2007

Figure source: IPCC WG1 (2007) +142% +18% Methane Nitrous Oxide

Projecting Future Climate: Greenhouse Gas Emissions Scenarios Emissions scenarios are used to “drive” global climate models. Different scenarios result in different climate change projections. Figure sources: IPCC 2001, Summary for Policy Makers Each “family” makes different assumptions about: population growth, economic development, forms of energy, agricultural production, etc.

Figure source: IPCC 2007 WG1, Summary for Policy Makers IPCC “best estimate” range of global-scale warming by the 2090s: 3.2°F-7.2°F (likely range: °F) Without drastic changes in current emissions trends, GHG concentrations will increase dramatically over the 21 st century and with that, global temperature.

Projected Increases in Annual PNW Temperature * Relative to average Mote and Salathé, 2009 °F°F°C°C Historic 2020s+2.0°F ( °F) 2040s +3.2°F ( °F) 2080s+5.3°F ( °F) (Low emissions) (Moderate emissions)

Historic Mote and Salathé, 2009 Projected Increases in Annual PNW Precipitation * Relative to average 2020s+1% (-9 to 12%) 2040s +2% (-11 to +12%) 2080s+4% (-10 to +20%)

Projected Changes in Days Above 92°F – Seattle Area (showing results for moderate [& high] warming scenarios) Baseline: Mean # events: 1.7 | Mean (max) duration in days: 2.2(6) 2025 Mean # heat events: 3.6 [5.8] Mean (max) duration in days: 2.3(7) [2.7(18)] 2045 Mean # heat events: 4.7 [8.8] Mean (max) duration in days: 2.6 (14) [3.2(18)] 2085 Mean # heat events: 7.2 [10.1] Mean (max) duration in days: 2.9 (18) [6.1(57)] Jackson et al. 2010

What About Changes in Extreme Precipitation? Simulations generally indicate increases in extreme precipitation over the next 50 years, however: – The projections vary by model and region, and – Actual changes may be difficult to distinguish from natural variability. Salathé et al. 2010, Rosenberg et al. 2010)

Sometimes you’ve got it.... Snow

Photo source: World Meteorological Organization...and sometimes you don’t.

( The Cascade and Olympic Mountains have the highest fraction of “warm snow”* in the continental U.S. Warm snow = snow falling between 27-32°F (Mote et al. 2008) The “Cliff Clavin” Fact

Elsner et al. 2010;. Map: Rob Norheim Low Medium -29% -44% -65% -27% -37% -53% Key Impact: Loss of April 1 Snow Cover

Three types of basins “transient” – double peaked snowmelt-dominantrain-dominant

Impacts on Seasonal Streamflow Timing Mixed Rain/Snow (Transient) Basin Elsner et al Increasing winter flows Earlier, lower peak runoff Lower summer streamflow Naturalized flows (i.e., no dams)

Impacts on Seasonal Streamflow Timing Vano et al Oct 1 Red line = historical weekly averages, Black line = composite value for the 2020s Gray area = the range of the in ensembles Naturalized flows (i.e., no dams) Dark grey line = composite value for the 2040s Dotted gray line = composite value for the 2080s Green River Sept 30

Slide courtesy of Paul Fleming, SPU

General increase in risk of winter flooding in western WA and combined sewer overflows in low- and mid-elevation basins Changes in urban flooding less clear Drainage infrastructure designed using historical rainfall records may not meet future required capacity as precipitation intensity and extremes become more severe. Urban Flooding & Stormwater Infrastructure

Impacts on Salmon - Freshwater Impacts vary by stock, life stage, and location. Impacts in freshwater largely driven by: Higher winter streamflows (scouring of redds) Higher winter streamflows (scouring of redds) Earlier peak spring streamflows (juvenile transport) Earlier peak spring streamflows (juvenile transport) Lower summer streamflows (stranding) Lower summer streamflows (stranding) Warmer summer streamflows (thermal stress) Warmer summer streamflows (thermal stress)

Washington State Sea Level Rise Medium (w/range) estimates of sea level rise in Washington for 2100:. NW Olympic Peninsula: +2” (-9 to +35”) Central/Southern Coast: +11” (+2 to +43”) Puget Sound: +13” (+6 to +50”) Mote et al. 2008

Alki Beach, West Seattle Photo by Hugh Shipman, WA Dept of Ecology

Alki Beach, West Seattle, January 21, 2010 Photo by Hugh Shipman Source: Washington Dept of Ecology

Near-term Challenges of SLR Sea level rise increases storm surge and the risk of: flooding, erosion, habitat loss These impacts will affect coastal areas long before permanent inundation.

For much of Puget Sound… A one foot of sea level rise turns a 100 year flood event into a 10 year event. A two foot sea level rise turns a 100 year flood event into an annual event. Changing Coastal Flood Risk Numbers and photos courtesy of Hugh Shipman, Washington Dept. of Ecology

Human Health Vulnerable populations include: Young children & infants; the elderly; those with compromised immune systems; mentally ill populations; urban poor, racial/ethnic minorities; socially-isolated Jackson et al *Population held constant at 2025 projection so numbers reflect influence of climate alone Changes in heat events and projected excess deaths in Seattle metro area*

Air Quality Reductions in summer air quality likely via the contribution of warmer air temperatures to: ground-level ozone formation West-side forest fire risks Jackson et al. 2010

Climate change requires changes in how we plan, design, and manage the infrastructure, services, and functions of a community.

Taking steps to avoid or minimize known climate change impacts while increasing the ability of human and natural systems to “bounce back” from the impacts that cannot be avoided (or anticipated) What Does it Mean to Adapt to Climate Change?

Zoning rules and regulations Taxation (including tax incentives) Building codes/design standards Utility rates/fee setting Public safety rules and regulations Issuance of bonds Infrastructure development Permitting and enforcement Best management practices Outreach and education Emergency management powers Partnership building with other communities General Implementation Tools

Dealing with Uncertainty We rarely have perfect information. Uncertainty is everywhere. – Should I buy earthquake insurance? – Should I change jobs? – How long will this recession last? Somehow we manage… – Identify options, – Build theories, – Evaluate risk, – Learn from experience, – Rely on experts/peers Thanks to Tom Pagano, USDA NRCS, for much of this slide

“No regrets” strategies Provides benefits now with or without climate change “Low regrets” strategies Provide climate change benefits for little additional cost or risk “Win-win” or “Co-benefit” strategies Reduce climate change impacts while providing other environmental, social, or economic benefits Planning for Uncertainty de Loë et al. 2001;Willows and Connell 2003; Luers and Moser 2006

Important Closing Considerations The future will not present itself in a simple, predictable way, as natural variations will still be important for climate change in any location The results presented here are projections, not predictions. While we expect the direction of the trends to remain consistent, specific values will vary over time.

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