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Chacaltaya Glacier, Bolivia, ~5240m
An Update on Global WarmingRay Bradley
Climate System Research CenterUniversity of Massachusetts
Amherst
Senator James Inhofe(R-Oilahoma)
“The threat of catastrophic global warming is the greatest hoax ever perpetrated on the American people … man-induced global warming is an article of religious faith…”
“Northern Hemisphere temperatures during the past millennium: inferences, uncertainties and limitations”
M. Mann, R. Bradley & M. Hughes, 1999
WARMEST 50 YEARS BEFORE 1900: 1146-1195
COLDEST 50 YEARS BEFORE 1900: 1453-1502
“Mann[et al] effectively erased the well-known phenomena of the Medieval Warming Period--
when, by the way, it was warmer than it is today--and the Little Ice Age…” J. Inhofe 2005
Source: Houghton et al., 2001
Homo sapiensHomo erectus Dec 4th 2005: 380ppm
180ppm
280ppm
Blue=CO2 (carbon dioxide)
Red=CH4 (methane)
Hundreds of thousands of years before today
Source: Houghton et al., 2001
Homo sapiensHomo erectus
180ppm
280ppm
Blue=CO2 (carbon dioxide)
Red=CH4 (methane)
Hundreds of thousands of years before today
Dec 4th 2005: 380ppm
~760ppm
First Cities
270
275First Writing
Internal combustion engineNew World colonizationThe Crusades
1 hour = 6000 years;
1 minute = 100 years
280
280290
Time…
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70
200
300
400
500
600
700
800
900
1000
latitude
mb
-50 -40 -30 -20 -10 0 10 20
°C
NCEP Reanal. Mean Annual Temp - Cordillera Transect (1973-2002)
Freezing level
1932:Glacier National Park
Boulder ice cave
http://www.nrmsc.usgs.gov/research/FTP-Instructions_repeatphotos.pdf
1988:
Glacier National Park
Boulder ice cave
Permafrost occurrence at the Matterhorn
Source: Gruber & Biegger 2003
Permafrost
Permafrost probable
Zermatt
Climate change in mountains affects water supply
current averagesnow water equivalentin Sierra Nevada (CA)
Current average Aprilsnow water equivalentin Sierra Nevada (CA)
Percent reduction in AprilSWE with 1.6 °C rise by 2060
Even in non-glaciated mountains such asin Central California, warming will leadto more rain and less snow, and earlier melting,
(Knowles and Cayan 2004)
Shifting the timing offresh water runoff impacts Deltawater quality
more in winter= flooding?
less in summer= salt-water
intrusion
Yearly changes in ocean heat content (1955–59 to 1994–98)(units = 1022 J)
Source: Levitus et al., 2005
Trends in ocean heat content (1955-2003).Pink = increasing
Contour interval is 2 x 1018 J year-1 Source: Levitus et al., 2005
Greenhouse gas forcing
Annual mean temperature change, 2071 to 2100, relative to 1990: global average in 2085 = +3.1oC
Number of years to add each billion Year
Ninth
Eighth
Seventh
Sixth
Fifth
Fourth
Third
Second
First Billion All of Human History
130 193030 196014 197413 198712 199914 201315 2028 26 2054
1800
Sources: Population Reference Bureau; UN World Population Prospects (1998)