An Update on Global Warming

An Update on Global Warming
Ray Bradley
Climate System Research Center
University of Massachusetts
Amherst
Chacaltaya Glacier, Bolivia, ~5240m
“The threat of catastrophic
global warming is the greatest
hoax ever perpetrated on the
American people … maninduced global warming is an
article of religious faith…”
Senator James Inhofe
(R-Oilahoma)
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
Blue=CO2 (carbon dioxide)
Red=CH4 (methane)
Homo erectus
Homo sapiens
Dec 4th 2005: 380ppm
280ppm
180ppm
Hundreds of thousands of years before today
Source: Houghton et al., 2001
~760ppm
Blue=CO2 (carbon dioxide)
Red=CH4 (methane)
Homo erectus
Homo sapiens
Dec 4th 2005: 380ppm
280ppm
180ppm
Hundreds of thousands of years before today
Source: Houghton et al., 2001
CO2 change over the last 650,000 years
Source: Siegenthaler et al., 2005
Internal combustion engine
New World
290
colonization
280
The Crusades
280
First Cities
270
1 hour = 6000
years;
1 minute = 100
years
First
Writing
275
Time…
2003
2005
2003
NCEP Reanal. Mean Annual Temp - Cordillera Transect (1973-2002)
200
300
400
mb
500
Freezing level
600
700
800
900
1000
-50 -40 -30 -20 -10
0
10
20
30
40
0
10
20
latitude
-50 -40 -30 -20 -10
°C
50
60
70
1932:
Glacier National Park
Boulder ice cave
1988:
Glacier National Park
Boulder ice cave
http://www.nrmsc.usgs.gov/research/FTP-Instructions_repeatphotos.pdf
1910
Recession of
the Grinnell
Glacier
1931
“Glacier
National Park”
1997
Source: D. Fagre, USGS, 2004
1929
2000
1930
Photo: Mittelholzer,
Kilimanjaro Flug
5
Photo credit: Nicolas Cullen, Univ. Innsbruck
Glacier on Volcán Lanin, Argentina, 1896 and 2001
Chacaltaya Glacier
Bolivia:
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
Permafrost
Permafrost
probable
Zermatt
Source: Gruber & Biegger 2003
Climate change in mountains affects
water supply
Shifting the timing of
fresh water runoff
impacts Delta
water quality
Current average April
snow water equivalent
in Sierra Nevada (CA)
current average
Percentsnow
reduction
April
waterinequivalent
SWE with
1.6 °CNevada
rise by (CA)
in Sierra
2060
(Knowles and Cayan 2004)
Even in non-glaciated mountains such as
in Central California, warming will lead
to more rain and less snow, and earlier
melting,
less in summer
= salt-water
intrusion
more in winter
= flooding?
30°N-30°S: 3.8%
increase in total water
vapor since 1970
Source: Trenberth, NCAR 2005
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 forcing
Annual 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
First Billion
Second
Third
Fourth
Fifth
Sixth
Seventh
Eighth
Ninth
Year
All of Human
History
130
30
14
13
12
14
15
26
1800
1930
1960
1974
1987
1999
2013
2028
2054
Sources: Population Reference Bureau; UN World Population Prospects (1998)
Conservation [less waste], reduced consumption
+ alternative energy sources
Source:
R. Hoblitt, USGS
1834
WARMEST
EUROPE
COLDEST
1838
EUROPE
Source: Mann et al., 2000
For accurate information about
climate change & global warming,
see:
http://www.realclimate.org
www.paleoclimate.org