Transcript Evaluating Washington`s Future in a Changing Climate

Washington Climate Change Impacts Assessment
Evaluating Washington’s Future in a Changing
Climate
• House Bill 1303, April 2007
– Charged state departments to work the UW
Climate Impacts Group with WSU and PNNL
– Produce a comprehensive assessment of the
impact of climate change on the State of
Washington
• Approach
– Downscale IPCC Climate Model outputs to
WA over the next 50 years
– Assess impacts in eight sectors:
Washington Climate Change Impacts Assessment
Evaluating Washington’s Future in a Changing
Climate
• Approach
– Downscale IPCC Climate Model outputs to WA over the next 50 years
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A1B (more emissions) from 20 models
B1 (less emissions) from 18 models
Regional scenarios for precipitation and temperature: 2020s, 2040s, 2080s
Sea level rise 2050 and 2100
– Assess impacts in eight sectors
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Hydrology and Water Resources
Energy
Agriculture
Salmon
Forests
Coasts
Urban Stormwater Infrastructure
Human Health
– Assess the needs for adaptive planning and adaptive options within
each sector
UW Climate Impacts Group
Washington State
Climate Change
Impacts Assessment:
HB 1303 Key Findings
Marketa McGuire Elsner
Jeremy Littell
JISAO CSES Climate Impacts Group
University of Washington
Washington State University
Pacific Northwest National Laboratory
Climate science in the
public interest
Project Team
• Scenarios
(E. Salathé, P. Mote)
– CIG, UW, PNNL
• Hydrology and Water Resources
(D. Lettenmaier, M. Elsner)
– CIG, UW
• Energy – Hydropower
(A. Hamlet)
– CIG, UW
• Forests
(D. McKenzie, J. Littell)
– CIG, UW, USFS, Univ. ID
• Coasts
(D. Huppert)
– CIG, UW
• Urban Stormwater Infrastructure
(A. Steinemann, D. Booth)
– UW, Stillwater Sciences, King Co. Water and Land
Resources Div., Northwest Hydraulic Consultants
• Agriculture & Economics (Stockle,
• Human Health
Scott)
(R. Fenske)
– WSU, USDA ARS, PNNL
• Salmon
(N. Mantua)
– CIG, U
– UW, WSU, Institute for Chemical Process and Envir.
Tech. - Canada, CA Air Resources Board
• Adaptation
(L. Whitely-Binder)
– CIG, UW
Assessment
Overview:
Study Region
Scientific progress,
assessment limitations
• Progress:
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Vertical integration of climate change projections
Wide range of research areas
Narrowing of uncertainty with many climate models
Quantified impacts and ranges for decision making
• Limitations:
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Modeling climate variability (interannual, decadal)
Interactions or synergies between impacts
Uncertainty in climate and projections
There may be thresholds we have yet to understand
Projected Increases in Annual PNW Temperature
* Compared with 1970-1999 average
2080s
2040s
2020s
+5.9°F
+3.5°F
+2.2°F
°C
Mote and Salathé, 2009
°F
Projected Changes in Annual Precipitation
* Compared with 1970-1999 average
Changes in annual precipitation averaged over all models are small but
some models show large seasonal changes, especially toward wetter
autumns and winters and drier summers.
Mote and Salathé, 2009
Regional climate model projections
Salathé et al, 2009
Hydrology and water resources
37-44% change (B1/A1B)
* Compared with 1916-2006 average
Elsner et al. 2009
Mantua et al. 2009
Yakima Economics - Production Value
Thousand 2007$
Cherries
B1 2020s
$500
$450
$400
$350
$300
$250
$200
$150
$100
$50
A1B
$0
Apples
Cherries
Apples
2040s
B1 2040s
Historical A1B 2020s
Conditions
(1975-2004)
B1 2020s
2020s
A1B 2080s
A1B 2040s
B1 2080s
B1 2040s
2040s
A1B 2080s
B1 2080s
2080s
Scenario
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Scenario
Reservoir
system will be less able to supply water to all users, especially
those with junior water rights.
Junior and senior water user averaged, impacts include CO2 fertilization
Production decreases by 5% in 2020s, 16% in 2080s (relative to historical)
Production values are buffered somewhat by price increases and largely
unchanged production on senior water user lands
Vano et al. 2009b
Puget Sound Basin
municipal supply - current demand
• Municipal and Industrial,
reliability measures differ
across systems
• With current demands, system
reliability able to
accommodate changes (A1B)
• With demand increases, system
reliability reduced,
conservation measures matter
Note: simulations do not include
adaptation
Vano et al. 2009a
Tacoma, water allocations
closer to current system
capacity
Current Demand
historic
2020s
2040s
2080s
100%
80%
60%
1%
7%
0%
Seattle M&I
Tacoma FDWR
Everett M&I
40%
20%
0%
Everett, largest system
capacity
* Projections compared to water year 1917-2006 average
Energy
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Annual hydropower production is projected to decline by
a few percent due to small changes in annual flow, but
seasonal changes will be substantial.
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Winter hydropower production is projected to increase by
about 0.5-4.0% by the 2020s, 4.0-4.2% by the 2040s, and
7%-10% by the 2080s (compared to water year 1917-2006)
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Summer energy production is projected to decline by 10%
by the 2020s, 15% by the 2040s, and 20% by the 2080s. At
the same time summer cooling demands may increase by
400%
Hamlet et al. 2009
Energy
Changes in system-wide hydropower production in the Columbia system for three
future time frames: large declines in summer, slight increases in winter.
Hamlet et al. 2009
Agriculture
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Given sufficient irrigation, the projected impact of climate
change on eastern Washington agriculture is unlikely to
be severe. Likely changes in yields from climate alone are
increases in winter wheat (2-8% by the 2020s), decreases
in irrigated potatoes (15% by the 2040s) and decreases in
apples (3% by the 2040s).
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However, the combination of warming and elevated CO2
could provide significant potential benefits that offset
these declines. There is some uncertainty about whether
the CO2 effect is transient, but for well managed crops in
eastern WA, the beneficial effect of elevated CO2 will most
likely be positive.
Stöckle et al. 2009
Salmon and Ecosystems
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Rising stream temperature will reduce the quality and
quantity of freshwater salmon habitat substantially.
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The duration of temperatures causing thermal migration
barriers and extreme thermal stress (where weekly water
temperatures exceed 70°F) are predicted to quadruple by
the 2080s.
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Water temperatures for Western Washington stations are
generally cooler, and predicted impacts on thermal stress
are significant but less severe.
Mantua et al. 2009
Salmon and Ecosystems
August Mean Surface Air Temperature and Maximum Stream Temperature
Historical (1970-1999)
2040s medium (A1B)
* Projections are compared with 1970-1999 average
Mantua et al. 2009
Forests
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The area burned by fire regionally (in the U.S. Columbia
Basin) is projected to double or triple (medium scenario,
(A1B)), from about 172,000 ha annually (1916-2006) to 0.3
million ha in the 2020s, 0.5 million ha in the 2040s, and 0.8
million ha in the 2080s.
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Due to climatic stress on host trees, mountain pine beetle
outbreaks are projected to increase in frequency and
cause increased tree mortality. Climatically suitable
habitat for pine species susceptible to mountain pine
beetle is likely to decline but increase in elevation by the
2040s.
Littell et al. 2009
Forests
Current
2060s
Changes in the potential climatically suitable range of lodgepole pine
(Data: Rehfeldt et al. 2006, multiple IPCC scenarios).
Littell et al. 2009
Coasts
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A previous study involving the Climate Impacts Group found that
sea level rise in Puget Sound might be as little as 6” or as much
as 50” by 2100.
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Sea Level Rise (SLR) will shift the coastal beaches and increase
erosion of unstable bluffs, endangering houses and other
structures built near the shore or near the bluff edges.
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Shellfish will possibly be negatively impacted by increasing ocean
temperatures and acidity, shifts in disease and growth patterns,
and more frequent harmful algal blooms (HAB).
Huppert et al. 2009
Urban Stormwater Infrastructure
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Drainage infrastructure designed using mid-20th century
rainfall records may be subject to a future rainfall regime that
differs from current design standards. Results from regional
climate models suggest increased extreme rainfall in late autumn
in western Washington.
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Hydrologic modeling of two urban creeks in central Puget
Sound suggest overall increases in peak annual discharge over
the next half-century, but only those projections resulting from
one of the two RCM simulations are statistically significant.
Magnitudes of projected changes vary widely, depending on the
particular basin under consideration and the choice of the
underlying global climate model.
Rosenberg et al. 2009
Changes in Flood Risks
• Floods in western WA will likely increase in
magnitude due to the combined effects of
warming and increasingly intense winter storms.
• In other parts of the State, changes in flooding are
smaller, and in eastern WA projected reductions in
flood risk are common due to loss of spring snow
cover.
Mantua et al. 2009
Human Health
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In Washington, climate change will lead to larger numbers of
heat-related deaths due mainly to hotter summers and
population growth. For example in Seattle a medium climate
change scenario projects 101 additional deaths for people over
45 by 2025 and another 50% increase by 2045
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Although better control of air pollution has led to improvements
in air quality, warmer temperatures threaten some of the
sizeable gains that have been made in recent years.
Jackson et al. 2009
Human Health
Jackson et al. 2009
Percent Increase in Risk of Death, and Number of Deaths Each Day for All NonTraumatic Causes by Heat Event Duration, Greater Seattle Area, 1980-2006.
Adaptation Options and Opportunities
• Climate change impacts over the next few decades are
virtually certain. Impacts beyond this timeframe will be
greatly influenced by how successfully we reduce
greenhouse gas concentrations both in the near-term
and over time.
• State and local governments, businesses, and residents
are on the “front line” when it comes to dealing with
climate change impacts.
• Decisions with long-term impacts are being made every
day, and today’s choices will shape tomorrow’s
vulnerabilities.
Whitely Binder et al. 2009
Conclusions
Adaptation to climate change impacts is necessary because the projected
impacts within and across sectors are large.
To the extent that it can be identified, quantified, and mitigated, uncertainty
is a component of planning, not a reason to avoid planning.
Many sectors report different impacts in different systems (e.g., snowpack
response at low vs. high elevations, fire response in the western Cascades vs.
Blue Mountains, different species of salmonids, different crops etc.), but the
natural spatial and temporal complexity of these systems is a key part of
planning for the future.
By understanding the direction and magnitude of projected climate changes
and their impacts, we can better manage risks and capitalize on opportunities
to reduce impacts.