Transcript Whitley-Binder_ClimateChgImpacts_w_notes

OUR CHANGING CLIMATE AND ITS
IMPACTS
An overview of climate change, climate impacts, and why it matters
Lara Whitely Binder
UW Climate Impacts Group
ITEP Tribal Air Quality Conference
June 16, 2011
Climate science in
the public interest
Key Points to Today’s Talk
•
Human activities are altering and will continue to alter 21st
century climate. How we experience climate change is a
function of natural variability and climate change.
•
Effects of a changing climate are already apparent, although
also reflective of natural variability.
•
Projected “high confidence” impacts include increasing
temperatures, sea level rise, ocean acidification, declining
snowpack, and shifts in streamflow patterns and timing.
•
Information exists now for preparing for climate change
impacts.
What is Driving Present Day Climate Change?
The current concentrations of key greenhouse gases,
and their rates of change, are unprecedented in the last
10,000 years.
+ 35%
Carbon dioxide (CO2)
+ 142%
Methane (CH4)
+ 18%
Nitrous Oxide (N2O)
Longer-term CO2 Trends
 Current concentrations
are higher than any time
in at least the past
~780,000 years
2010
 ~70% of CO2 emissions
come from fossil fuel
burning (chemical
“fingerprint”)
 2010 avg annual CO2
concentration: 389 ppmv
From a long term perspective, these changes are enormous
Average global temperature has increased 1.3°F since 1906.
Warming since the 1950s very likely (>90% probability)
due to the observed increase in GHG from human activities.
Figure source: IPCC 2007
Recent U.S. Temperature Trends
Average annual
temperature in most
areas of the U.S. have
warmed 1 to 2°F since
1961.
High-humidity heat
waves (key char: high
nighttime temps)
have increased in the
last 3 to 4 decades.
Source: USGCRP 2009
20th Century PNW Temperature Trends
Temperature Trends (°F per century), since 1920
Average annual
temperature
increased +1.5F in
the PNW during the
20th century
Cooler Warmer
3.6 °F
2.7 °F
1.8 °F
0.9 °F
• Much of the warming
took place after 1950
• Most of the warming
has occurred in winter
and spring
• An estimated 1/3 of
warming attributable
to ENSO and PDO
Mote 2003(a), updated
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Arctic sea ice extent has declined
(-34%, 1979-2009) (NASA 2009a)
• Mean thickness has declined
(- 23% , 1987-2007) (NASA 2009b)
• Seasonal ice is now the dominant ice type
(Kwok et al. 2009)
• The Arctic sea ice melt season has lengthened
(20 days longer on average, 1979-2007)
(Markus et al. 2009)
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• The growing season in the U.S. and
Canada has increased
(+2 days/decade on average
since 1950)
(IPCC 2007, WG2)
• Primary driver: earlier onset of
spring (IPCC 2007, WG2; Linderholm et al 2006)
• Changes in growing season length
vary by region, altitude, and
latitude (Linderholm et al 2006)
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Northern hemisphere
spring snow cover
has declined
(~8%, 1922-2005)
(Lemke et al., 2007)
• Western U.S. spring
snowpack has
declined
(decreased in 73%
(n=824)of stations,
1950-1997) (Mote et al. 2005)
Decrease Increase
Mote et al. 2005
Over the past 1,000 yrs, late 20th-century
(1980s to present) snowpack reductions are
almost unprecedented in magnitude across the
northern Rocky Mountains
Pederson et al. 2011
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Northern hemisphere
spring snow cover
has declined
(~8%, 1922-2005)
(Lemke et al., 2007)
• Western U.S. spring
snowpack has
declined
(decreases in 73%
(n=824)of stations,
1950-1997) (Mote et al. 2005)
• Spring snowmelt and
peak runoff have
shifted earlier
(1 to 4 weeks in much
of the western U.S.,
1948-2002)
(Stewart et al. 2005)
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Northern hemisphere
spring snow cover
has declined
(~8%, 1922-2005)
(Lemke et al., 2007)
• Spring snowpack has
declined
(decreases in 73%
(n=824)of western
U.S. stations, 19501997) (Mote et al. 2005)
• Spring snowmelt and
peak runoff have
shifted earlier
(1 to 4 weeks in much
of the western U.S.,
1948-2002)
(Stewart et al. 2005)
• Northern hemisphere
glaciers are losing
mass and/or length.
Mount Baker-Snoqualmie National
Forest
South Cascade Glacier
Photos courtesy of Dr. Ed Josberger, USGS Glacier Group, Tacoma, WA
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Ocean pH has decreased 30%
(drop of ~0.1 since ~1750)
(Feely et al. 2008)
• Some of the strongest areas of
acidification are in upwelling
zones along the U.S. west coast
(Feely et al. 2008)
Evidence of change is increasingly visible throughout
Earth’s natural systems
Observed 20th century change
• Ranges for algal, plankton, and
fish have shifted poleward in
high-latitude oceans.
• Plant and animal ranges are
shifting northward and to higher
elevations.
IPCC WG2 2007, Janetos et al. 2008
Changes in USDA Hardiness Zones
http://www.arborday.org/media/mapchanges.cfm
Climate Modeling, Climate Projections, and Projected National and Regional Change
PROJECTED CHANGES IN CLIMATE
Projecting Future Climate:
Greenhouse Gas Emissions Scenarios
40 emissions scenarios are used to “drive” global climate models.
Different scenarios result in different climate change projections.
CO2 Emissions Scenarios
CO2 Concentrations
A1FI
A2
A1FI
A2
A1B
A1B
B1
B1
Current emissions are in the current range of the A1B scenario.
Figure source: IPCC 2001, Summary for Policy Makers
Without drastic changes in current emissions trends, GHG
concentrations will increase dramatically over the 21st
century and with that, global temperature.
IPCC “best
estimate” range
of global-scale
warming by the
2090s:
3.2°F-7.2°F
(likely range: 2-11.5°F)
Figure source: IPCC 2007 WG1, Summary for Policy Makers
B1
A1B
More warming
is expected
over land
surface and in
the Northern
Hemisphere
A2
Projected surface
temperature changes
for the early and late
21st century, relative to
1980 to 1999
Figure source: IPCC 2007 WG1, Technical Summary, Fig TS.28
End of Century (2080-2099 Average)
Projected Temperature Change (°F),
relative to 1961-1979 baseline
Lower Emissions Scenario
(B1)
Range: +4 to +6.5°F
USGCRP 2009
Higher Emissions Scenario
(A2)
Range: +7 to +11°F
A2 Scenario
USGCRP 2009
Projected Increases in
Annual PNW Temperature
* Relative to 1970-1999 average
2020s
+2.0°F (1.1-3.4°F)
2040s
+3.2°F (1.6-5.2°F)
2080s
+5.3°F (2.8-9.7°F)
Historic
°C
°F
Mote and Salathé, 2009
Projected Change in North American
Precipitation, 2080-2099
A2 Scenario
hatching = areas with highest confidence
USGCRP 2009
Projected Increases in
Annual PNW Precipitation
2020s
+1% (-9 to 12%)
2040s
+2% (-11 to +12%)
* Relative to 1970-1999 average
2080s
+4% (-10 to +20%)
Historic
Mote and Salathé, 2009
Increasing
Extreme
Precipitation
Nationally, the
1-in-20 year
extreme precip
events is
expected to be
10 to 25%
heavier by the
2090s than
present day
(specific changes vary
by location).
USGCRP 2009
What About Changes in PNW
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. 2009, Rosenberg et al. 2009)
Key Impact:
Reduced Spring Snow Cover
-29%
-23%
1916-2006
Red shading
indicates areas
where April 1
snowpack is
expected to decline.
Chapter 5 - Macro-Scale Hydrologic Model Implementation, Elsner and Hamlet (2010), http://www.hydro.washington.edu/2860/. Map by Rob Norheim, CIG
Runoff patterns are temperature dependent, but the basic
response is more runoff and streamflow in winter and early
spring, with less in late spring and early summer
A transient (snow/mix basin)
Increasing winter
flows
Earlier, lower
peak runoff
Lower summer
streamflow
Elsner et al. 2009
Impacts to Seasonal Streamflow Timing cont.
Rain and Snowmelt Dominant Basins
Rain Dominant
Snowmelt Dominant
Sea Level is Expected to Increase
Major determinants of global sea
level rise:
• Thermal expansion of the
ocean
• Melting of land-based ice
sheets (Greenland, Antarctica)
Global Projections for 2100:
+7 to +23 inches (IPCC 2007)
and more recently
+2.6 ft to +6.6 ft (Pfeffer et al. 2008)
Jakobshavn Fjord, Greenland
Sea level will not stabilize until several
centuries after global temperatures
stabilize.
Washington State Sea Level Rise
Medium (w/range) estimates of sea level rise in Washington for 2100:
Puget Sound:
+13” (+6 to +50”)
Central/Southern Coast:
+11” (+2 to +43”)
.
Mote et al. 2008
NW Olympic Peninsula:
+2” (-9 to +35”)
Ocean Acidification
• Oceans have absorbed approximately 1/3 of the
carbon emissions released by human activities
since the preindustrial era.
• As a result, ocean water is becoming more
acidic.
• Projected increase in ocean acidity by 2100:
150% (IPCC A2 scenario)
Effects of increasing carbon dioxide and
temperature on coral reefs
Credit: NOAA Coral Reef Targeted Research and Capacity Building for Management Program
What Can Influence Species Vulnerability?
Functioning at the edge of
geographic/elevation ranges
e.g., alpine meadows
Dependence on specialized
habitat and/or microhabitat
requirements
e.g., Cascades frog (Rana cascadae)
Impacts affecting specific life
stages
e.g., emergent tree seedlings
Narrow environmental
tolerances or thresholds
e.g., temperature thresholds for
salmon
Source: Snover et al, in review; IUCN 2008; Josh Lawler, UW
Factors Influencing Vulnerability cont’d
Presence of feedbacks and
multiple stresses
e.g., drought stress and wildfire
Dependence on specific
environmental triggers
e.g., lodgepole pine
Dependence on interactions
between species
e.g., zooplankton, phytoplankton
blooms; freshwater mussels (glochidia)
Dr. Monica G. Turner, UW Madison
Poor ability to disperse or
colonize new ranges
e.g., corals, Rockfish, Dungeness Crabs
Clio pyramidata, R. Hopcroft, U of Alaska Fairbanks
NOAA
www.wildnatureimages.com
Population growth rates
Source: Snover et al, in review; IUCN 2008; Josh Lawler, UW
Climate Change Impacts on Pika Distribution
• Substantial reduction in area
of distribution projected
(decreases by 81-98%)
• Increasingly fragmented
distribution
Trook and Hicke, in revision
Slide courtesy of Jeff Hicke
Impacts to PNW Coastal Habitats
NWF (2007) evaluation of impacts to coastal habitat at 11 locations in
Washington and Oregon from 27.3” of sea level rise:
•
•
•
•
65% loss of estuarine beaches
61% loss of tidal swamps
44% loss of tidal flats
52% conversion of brackish marsh to
tidal flats, transitional marsh, and
saltmarsh
Loss could affect availability of this habitat for spawning, juvenile
rearing, migratory and over-wintering stopovers, commercial
shellfish production
National Wildlife Federation (2007), Sea-level Rise and Coastal Habitats in the Pacific Northwest
An Analysis for Puget Sound, Southwestern Washington, and Northwestern Oregon
Salmon Impacted Across Full Life-Cycle
Floods
Warmer
lower
flows in
summer
Warm, low
streamflow
Acidification,
warming, winds?
Modified from Wilderness Society (1993)
Changes in Species Distribution
Projected suitability changes: Lodgepole pine
Data: Rehfeldt et al. 2006; Map by Rob Norheim, UW CIG
Littell et al. 2009
Data: Rehfeldt et al. 2006; map: Rob Norheim, UW CIG
Changes in Species Distribution
Projected suitability changes: Douglas-fir (2060s)
*
*Modeled current distribution
Littell et al. 2009
Projected change (%) in area burned by ecoprovince for 1°C
increase in average global temperature.
Risk of Forest Fire
Increases
Figure source: Jeremy Littell, CIG. Map by Rob Norheim, UW CIG
The amount of area
burned throughout the
West is projected to
increase.
For the PNW as a whole,
probability of a year >> 2
million acres increases:
•
•
•
•
Historical: 5%
2020s: 5% (1 in 20)
2040s: 17% (~1 in 6)
2080s: 47% (~1 in 2)
Littell et al. 2009
Human Health – Washington State
•
In Washington, climate change will lead to larger numbers
of heat-related deaths due mainly to hotter summers. For
example in greater Seattle, a medium climate change
scenario projects 101 additional deaths for people over 45
by 2025 and another 50% increase by 2045
•
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
Information Sources
• ITEP
• University-based research programs (e.g., CIG, NOAA Regional
Integrated Sciences and Assessment programs [RISAs])
• Federal agencies:
– US EPA
– USGS Climate Science Centers
– Landscape Conservation Cooperatives
• National Research Council’s “America’s Climate Choices” report
series, specifically “Advancing the Science of Climate Change”
• US Global Change Research Program – “Global Climate Change
Impacts in the U.S.” report (2009) + 2nd Nat’l Assess. (2012?)
• Intergovernmental Panel on Climate Change (2007 report)
For questions, please contact
Lara Whitely Binder
Climate Impacts Group
University of Washington
[email protected]
F