Transcript The Climate Impacts Group

PNW Climate Change Impacts &
Related Studies
Marketa McGuire Elsner
Climate Impacts Group
Center for Science in the Earth System
Joint Institute for the Study of the Atmosphere and Ocean
University of Washington
November 28, 2007
Public Meeting of the League of Women Voters
Climate science in
the public interest
Why Climate Change Matters
 The PNW’s ecosystems, communities, and
economy are sensitive to changes in climate.
 Global and regional climate is already changing,
and these changes are expected to accelerate in
the coming decades.
 Significant climate change impacts are projected,
and the impacts expected in the next few decades
are largely unavoidable.
 Local governments are on the front line with
respect to dealing with climate impacts.
Models using natural forcings only
Models using natural and anthropogenic forcings
Observations
21st Century Warming in the PNW
Precipitation Projections - 21st Century
Trend in Apr 1
Snowpack
1950-2000
824 snow courses
73% – trends
Large – trends PNW
Some + trends SW
Lower Spring Snowpack
Spring snowpack is projected
to decline as more winter
precipitation falls as rain rather
than snow, especially in
warmer mid-elevation basins
+4°F, +4.5%
winter precip
Snowpack will melt earlier with
warmer spring temperatures
April 1
Snowpack
Simulated Changes in Natural Runoff Timing in the
Naches River Basin Associated with 2°C Warming
120
Simulated Basin Avg Runoff (mm)
100
80
Impacts:
•Increased winter flow
•Earlier and reduced peak flows
•Reduced summer flow volume
•Reduced late summer low flow
1950
60
plus2c
40
20
0
oct
nov
dec
jan
feb
mar
apr
may
jun
jul
aug
sep
Impacts on Water Resources
Warmer temperatures:
 More water, less snow in
winter mid- , low elevations
 Less water in summer
 Increased risk of winter
flooding in many basins
(changes in urban flooding less
clear)
 Increased risk of summer
drought
 Negative impacts on
hydropower production,
irrigation water supply,
instream flow protection
 More stress on urban water
supplies
Overall: climate change will require increasingly complex tradeoffs between competing management objectives
Washington State Climate
Impacts Assessment
Funding Source: Clean Air/Clean Fuels House Bill 1303
Answers to FAQ regarding HB 1303 from the Washington State Legislature website:
http://apps.leg.wa.gov/billinfo/default.aspx
Human Health
Infrastructure
Agriculture
Coast Lines
Water Resources
A comprehensive state
climate change
assessment that
includes the impacts of
global warming
Forest Resources
Energy
Salmon
Adaptation
/ Legal
Barriers
Hydrologic Scenarios Database for the
Columbia River Basin
Working in Coordination With
Regional Stakeholders
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
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
Ecology
BPA
NPCC
State of OR
British Columbia (BC Hydro,
Ministry of Environment)
Planning Framework
Incorporating Climate
Information and Uncertainty
 ~20 GCMs
 2 Emissions Scenarios
 2 Downscaling Approaches
 Large Scale Planning Studies
 WRIA Water Supply Planning
 Specific Planning Studies
• Motivation for writing grew
out of October 2005 King
County climate change
conference
• Written by the CIG and King
County, WA in association
with ICLEI – Local
Governments for
Sustainability
• Written to compliment
ICLEI’s “Climate Resilient
Communities” Program
• Focused on the process
(not a sector), and written
for a national audience
www.cses.washington.edu/cig/fpt/guidebook.shtml
Why Climate Change Matters
 Global and regional climate is already changing
 These changes are expected to accelerate in the
coming decades
 Changes in snowpack and streamflow caused by
rising temperatures will have important
consequences for resources across the Pacific
Northwest
 Climate Impacts Group strives to provide
information and tools to help planning and
adaptation
More information on PNW climate impacts
and planning for climate change is
available from
The Climate Impacts Group
www.cses.washington.ed/cig
Marketa McGuire Elsner
[email protected]
Climate science in
the public interest
21st Century Global Warming
Projected range of globalscale warming by the 2090s:
3.2°F-7.2°F
Warming expected through
21st century even if CO2
emissions end today due to
persistence of greenhouse
gases.
Estimated
atmospheric
lifetime of major
greenhouse gas
(per molecule)
Carbon Dioxide
~60% of warming from GHG
5 to 200 years
Methane
~20% of warming from GHG
8 to 12 years
Nitrous Oxide
~6% of warming from GHG
~120 years
CF4 (Perfluoromethane)
>50,000 years
Data source: IPCC 2001
ImpactsRegional
on OtherImpacts
PNW Resources
•
Salmon: increased stress from floods, warm streams, low
summer streamflows
•
Forests: increased risk of wildfire, vulnerability to insects,
decreased growth & regeneration
•
Coasts: inundation, erosion, habitat loss, flooding
•
Agriculture: increased production?, decreased irrigation
supply, increased heat stress/insects
•
Recreation/Tourism: shortened winter ski season
(improved access?), summer impacts from forest fires
•
Hydropower: increased winter production, lower summer
production
Overall: climate change will require increasingly
complex trade-offs between competing management
objectives
On-Line Survey Website
Project Scope
http://cses.washington.edu/cig/
http://www.surveymonkey.com/s.aspx?sm=daSOYBVOb238oFy6ia7bcA_3d_3d