Transcript How would we know if Colorado`s climate is changing and how will it

Is Colorado’s Climate Changing?
If so, how can we prove it?
Why should we care?
Colorado Snow Pack Graph
Niwot Ridge April 1st Snow Pack Data 1938-2008
30
Snow Water Equivalent (inches)
25
20
15
10
5
0
1930
1940
1950
1960
1970
1980
1990
2000
Time (Year)
ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/colorado/05j42s.txt
2010
2020
Colorado
Snowpack
Source:http://earthobservatory.nasa.gov/IOTD/view.php?id=5557
Type of Precipitation Rain vs Snow
FIGURE 2-8. Trend in Snow vs. Rain in Winter (1949–2004)
MORE SNOW
LESS SNOW
Fig. 2-8. Changes in the fraction of winter precipitation falling as snow vs.
rain (1949–2004), after correcting for trends in precipitation amount. Blues indicates increasing
fraction of snow; yellow decreasing fraction. Data are from NWS COOP stations. (from
Knowles et. al. 2006, FIGURE 7)
 Average Yearly Precipitation in Colorado 1900-2009

Colorado Climate Report 2008
Average Yearly Temperatures in Colorado 1900-2009
Colorado Climate Report 2008
Frequency of large forest wildfires vs. average
temperatures during fire season (March-August)
A. L. Westerling et al., Science 313, 940 -943 (2006)
Number of Days Over 100°F 1961-1979
Darker colors represent higher number of days over 100 F
Peak River Flow
Peak River Flow Days– South Platt River Basin
Arapaho Glacier, Boulder County, Colorado - comparison photos:
1898 (Photo J.R. Brackett):
1960 (Photo H. Waldrop)
2000 (Photo W.T. Pfeffer)
Rowe Glacier, Colorado - comparison photos
Rowe Glacier, August, 25, 1916 (Photographer: W.T. Lee; NSIDC)
Rowe Glacier, September 18, 2004 (Photographer: Andy Leach; leachfam.com)
Temperature Changes and the Change in the Latitudinal Location of Bird Species
Pika Habitat
http://cires.colorado.edu/science/spheres/ecology/pikas.html
What is projected for the future in
Colorado?
Future Projections -Temperature
Future projections - Temperature
Observed and Projected Temperature Rise for the
Southwest
The average temperature in the Southwest has already increased roughly 1.5°F
compared to a 1960-1979 baseline period. By the end of the century, average annual
temperature is projected to rise approximately 4°F to 10°F above the historical baseline,
averaged over the Southwest region. The brackets on the thermometers represent the
likely range of model projections, though lower or higher outcomes are possible.
Future Projections
Number of Days Over
100°F
The number of days in which the temperature exceeds
100°F by late this century, compared to the 1960s and
1970s, is projected to increase strongly across the
United States. For example, parts of Texas that recently
experienced about 10 to 20 days per year over 100°F are
expected to experience more than 100 days per year in
which the temperature exceeds 100°F by the end of the
century under the higher emissions scenario.91
Future Projections for Rain from Nov to May
Current
Future
What changes do you see?
Source: Kyoko Ikeda (Colorado Headwaters Project)
Future Projections for Snow from Nov to May
Current
Future
What changes do you see?
Source: Kyoko Ikeda (Colorado Headwaters Project)
Future projections
Projected Change in Spring Precipitation, 2080-2099
Percentage change in March-April-May precipitation for 2080-2099 compared to
1961-1979 for a lower emissions scenario (left) and a higher emissions scenario
(right). Confidence in the projected changes is highest in the hatched areas.
Future Projections - Runoff
Future Projections – Extreme Heat
Number of Days Over 100°F
The number of days in which the temperature exceeds
100°F by late this century, compared to the 1960s and
1970s, is projected to increase strongly across the
United States. For example, parts of Texas that recently
experienced about 10 to 20 days per year over 100°F are
expected to experience more than 100 days per year in
which the temperature exceeds 100°F by the end of the
century under the higher emissions scenario.91
Future projections – snowpack
Spread of West Nile
Impacts of the changes on you
What’s the climate change, or climate change projection
causing the impact?
2. How will it impact you?
3. What can you do to adapt or mitigate the impact?
1.
Impacts of the changes
resources