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