December 18,
2001-3
Copyright © 2001 Earth Policy Institute
This Year May be Second Warmest on Record
Lester R. Brown
Global temperature data for the first 10
months of 2001 indicate that it likely will be the second warmest
year since recordkeeping began in 1867. Following the all-time high
of 1998, this year's near-record extends a strong trend of rising
temperatures that began in the late 1970s. The 15 warmest years
since 1867 have all come since 1980.
This additional year of temperature data provides further evidence
that a new trend of rising temperature is bringing to an end the
period of relative climate stability that has prevailed since shortly
after the last Ice Age ended and agriculture began some 11,000 years
ago.
Monthly global temperature data compiled by NASA's Goddard Institute
for Space Studies in a series based on meteorological station estimates
going back to 1867 show that September 2001 was the warmest September
on record. August and October temperatures in 2001 were each the
second warmest on record.
Based on data for the first 10 months, the global average temperature
for 2001 is calculated at 14.51 degrees Celsius (58.1 degrees Fahrenheit).
The all-time high in 1998 was 14.68 degrees Celsius. (See figure
.)
Looking back over the last century, the average global temperature
climbed from 13.88 degrees Celsius in 1899-1901 to 14.45 degrees
in 1999-2001, an increase of 0.57 degrees. Fully two thirds of this
gainmore than 0.4 degreesoccurred in the century's two
closing decades.
After fluctuating around 14 degrees Celsius (57.2 degrees Fahrenheit)
during most of the century, the temperature has been above this
level every year since 1976. During the last several years, the
earth's temperature has fluctuated around 14.4-14.6 degrees Celsius.
The rise of nearly 0.6 degrees Celsius during the last century is
quite small compared with the projected temperature rise over the
next century of 1.4-5.8 degrees Celsius (2.5-10.4 degrees Fahrenheit)
according to the Intergovernmental Panel on Climate Change (IPCC).
Even the lower figure in that range would be more than double the
increase of the last century. The upper-end projection of 5.8 degrees
Celsius would be nearly 10 times as much.
The contrast in sea level rise for the last century and that projected
for this one is similarly worrying. During the last century, sea
level rose an estimated 0.1-0.2 meters (4-8 inches). The IPCC projects
that during this century sea level will rise from 0.1-0.9 meters
(4-36 inches).
The temperature rise of recent decades follows on the heels of rising
atmospheric concentrations of carbon dioxide (CO2), the principal
greenhouse gas responsible for global warming. During the first
two centuries of the Industrial Revolution from 1760 to 1960, atmospheric
CO2 levels climbed from an estimated 277 parts per million (ppm)
to 317 ppma rise of 40 ppm. But during the four decades from
1960 to 2001, CO2 concentrations climbed from 317 ppm to 371 ppm,
a gain of 54 ppm. (See figure .)
This accelerating rise in recent decades corresponds closely with
the growth in fossil fuel burning during this period.
Rising temperature is not an irrelevant abstraction. It brings countless
physical changesfrom more intense heat waves, more severe
droughts, and ice melting to more powerful storms, more destructive
floods, and rising sea level. These changes in turn affect not only
such obvious things as food security and the habitability of low-lying
regions, but also the species composition of local ecosystems.
Agriculture is particularly vulnerable to climate change. For example,
in the summer of 1988, record heat and drought in the American Midwest
pulled the U.S. grain harvest below consumption for the first time
in history. Fortunately for the scores of countries that import
grain from the United States, the nation had a large grain reserve
at the time and was able to satisfy importers' needs by drawing
down these reserves.
Climate change affects food security in many ways. In 2000, the
World Bank published a map of Bangladesh showing that a 1-meter
rise in sea level would inundate half of that country's riceland.
Bangladesh would lose not only half its rice supply but also the
livelihoods of a large share of its population. The combination
of a population of 134 million expanding by 2.7 million a year and
a shrinking cropland base is not a reassuring prospect for Bangladesh.
Climate change is also triggering widespread changes in ecosystems.
Recent years have brought heavy investments by governments and environmental
organizations to protect particular ecosystems by converting them
into parks or reserves. But if the rise in temperature cannot be
checked, there is not an ecosystem on earth that can be saved. Everything
will change.
An additional year of temperature data reinforces the concerns expressed
by the team of eminent scientists who produced the latest IPCC report,
Climate Change 2001. They make clear what is now becoming obvious
even to non-scientists: that fossil fuel burning is changing the
earth's climate.
The bottom line is that altering the earth's climate is serious
businessnot something to be taken lightly. We can curb climate
change by shifting from a carbon-based energy economy to one based
on hydrogen. We now have the technologies to do it. The economics
are falling into place. At issue is whether we can restructure the
energy economy before climate change spirals out of control.
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Copyright
© 2001 Earth Policy Institute
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FOR ADDITIONAL INFORMATION
From Earth Policy Institute
Lester R. Brown, Eco-Economy:
Building an Economy for the Earth (New York: W.W. Norton
& Company, 2001).
Lester R. Brown, Rising Sea Level Forcing Evacuation of Island
Country, Eco-Economy Update,
15 November 2001.
Lester R. Brown, Climate Change Has World
Skating on Thin Ice, Earth
Policy Alert, 29 August 2001.
From Other Sources
Seth Dunn, Global Temperature Steady
and Carbon Emissions Continue Decline, in Worldwatch
Institute, Vital Signs 2001: The Trends that are Shaping Our
Future (New York: W.W. Norton & Company, 2001), pp. 50-53.
Goddard Institute for Space Studies, NASA Goddard
Space Flight Center Earth Sciences Directorate, Global Temperature
Anomalies in .01 C, updated November 2001, http:/www.giss.nasa.gov/data.
IPCC, Climate Change 2001. Contributions of Working
Groups I, II, and II to the Third Assessment Report of the Intergovernmental
Panel on Climate Change (Cambridge and New York: Cambridge University
Press). Text and summaries available at http:/www.ipcc.ch.
C.D. Keeling, T.P. Whorf, and the Carbon Dioxide
Research Group, Atmospheric Carbon Dioxide Record from Mauna
Loa, Scripps Institution of Oceanography, University of California,
13 August 2001, http:/cdiac.esd.ornl.gov/
ftp/ndp001/maunaloa.co2.
LINKS
Carbon Dioxide Information Analysis Center
http:/cdiac.esd.ornl.gov
Intergovernmental Panel on Climate Change
http:/www.ipcc.ch
International Research Institute for Climate Prediction
http:/iri.ldeo.columbia.edu/
climate/cid/
National Climatic Data Center http:/lwf.ncdc.noaa.gov/oa/
ncdc.html
National Oceanic and Atmospheric Administration
(NOAA) http:/www.noaa.gov
Scripps Institution of Oceanography http:/www.sio.ucsd.edu
United Nations Framework Convention on Climate Change
http:/www.unfccc.de
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