1. Date Name of Meeting 1
Climate Change Impacts
in the United States
Third National Climate Assessment
Don Wuebbles
Chicago Botanic Garden June 7, 2014
2. Date Name of Meeting 2
National Climate Assessment
Assessment is required
every 4 years by Congress
through the 1990 Global
Change Research Act
This assessment is the most
comprehensive analysis ever
of how climate change is
affecting our nation now
and how it could affect it
into the future Read online or download at:
http://nca2014.globalchange.gov
3. Date Name of Meeting 3
The NCA Process
Inclusive, broad expertise
300 authors
60 member Federal Advisory Committee
Public engagement
Listening sessions around the country
Request for information, input reports
Extensive Review
National Academy of Sciences (2x),
agencies, public and expert review;
we responded to all comments
13. Date Name of Meeting 13
Certain Types of Extreme Events Show
Important Trends
– Heat waves are generally increasing; will likely
become longer and more severe.
– Cold waves are decreasing.
– More precipitation coming as larger events.
– Increasing risk of floods in some regions (NE, MW).
– Droughts increasing in some regions (SW, SE).
– Increasing intensity of Atlantic hurricanes is likely.
These trends are likely to continue.
14. Date Name of Meeting 14
Observed U.S. Trends in
Heavy Precipitation
15. Date Name of Meeting 15
Floods and Droughts: Clear Trends in
Certain U.S. Regions
Regional similarities between trends of
annual precipitation, droughts, and
extremes of river flooding
River-Flow Trends in Annual Maximum:
85-127 years ending 2008
Trends in Total Annual
Precipitation: 1909-2008
Peterson, T. C. et al., 2013
Drought Index
16. Date Name of Meeting 16
Projected
Global
Temperature
Change
17. Date Name of Meeting 17
Projected Temperature Change
18. Date Name of Meeting 18
Projected
Precipitation
Change by
Season
19. Date Name of Meeting 19
Illinois Summers Likely to be More
Like Southern U.S. by End of Century
Based on summer
average temperature
and precipitation
20. Date Name of Meeting 20
Sectors
• Water Resources
• Energy Supply and Use
• Transportation
• Agriculture
• Forestry
• Ecosystems and
Biodiversity
• Human Health
24. Date Name of Meeting 24
Ecosystems
“Ecosystems and the benefits they
provide to society are being affected by
climate change. The capacity of
ecosystems to buffer the impacts of
extreme events like fires, floods, and
severe storms is being overwhelmed.”
25. Date Name of Meeting 25
Midwest Forests
Composition expected to change as rising temperatures drive
habitats for many tree species northward.
26. Date Name of Meeting 26
The Great Lakes
Climate change will
exacerbate a range of risks
to the Great Lakes,
including changes in the
range and distribution of
certain fish species,
increased invasive species
and harmful blooms of
algae, and declining beach
health. Ice cover declines
will lengthen the
commercial navigation
season.
30. Date Name of Meeting 30
Climate Change Impacts in the United States
http://nca2014.globalchange.gov
Third National Climate Assessment
@usgcrpfacebook.com/usgcrp
#NCA2014
Don Wuebbles
Department of Atmospheric Sciences
University of Illinois