An Update on Global WarmingClimate change in mountains affects water supply current average snow...
Transcript of An Update on Global WarmingClimate change in mountains affects water supply current average snow...
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…”
Max Trends (1950-2003)
Source: Trenberth, NCAR 2005
Source: Raynaud et al., 2003
“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
Source: Siegenthaler et al., 2005
CO2 change over the last 650,000 years
First Cities
270
275First Writing
Internal combustion engineNew World colonizationThe Crusades
1 hour = 6000 years;
1 minute = 100 years
280
280290
Time…
2003
20032003
2005
-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
1910Recession of the Grinnell Glacier
“Glacier National Park”1931
1997
Source: D. Fagre, USGS, 2004
1929
2000
1930Photo: Mittelholzer,
Kilimanjaro Flug
5 Photo credit: Nicolas Cullen, Univ. Innsbruck
Glacier onGlacier on VolcVolcáán Laninn Lanin, Argentina, 1896 and 2001 , Argentina, 1896 and 2001
Chacaltaya GlacierBolivia:Water supply for La Paz
5M m3 m in 1940
<0.3M m3 m today
Widespread (global) glacier recession
169 glaciers:
Source: Oerlemans, 2005
Source: Trenberth, NCAR 2005
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
Source: Trenberth, NCAR 2005
30°N-30°S: 3.8% increase in total water vapor since 1970
Source: Enfield et al., 2001
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
Greenhouse gas forcingAnnual mean precipitation change: 2071 to 2100, relative to 1990
Source: Overpeck et al.,2003
The Earth at night
Today there are ~6.3B people, & our impact on the planet is ubiquitous…
World population is currently increasing by 240,000 per day….
By 2060, UN projections indicate world population will be ~9B…
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)
Conservation [less waste], reduced consumption + alternative energy sources
Source: R. Hoblitt, USGS
WARMESTEUROPE1834
COLDEST
EUROPE1838
Source: Mann et al., 2000
For accurate information about climate change & global warming, see:
http://www.realclimate.org
www.paleoclimate.org