In 1995, more than two thousand scientists from one hundred coun-
tries reported to the United Nations that our burning of oil, coal, and
natural gas is changing the earth’s climate. Nearly a decade later, many
of the same researchers are very troubled by two things: The climate is
changing much more quickly than they projected even a few years ago,
and the systems of the planet are far more sensitive to even a very
small degree of warming than they had realized. The average global
temperature, the report said, will rise by 3 to 10° F by the end of the
twenty-first century.
The accelerating rate of climate change is spelled out in two recent
studies—one on the environmental side, one on the energy side.
In 2001, researchers at the Hadley Center, Britain’s principal cli-
mate research institute, found that the climate will change 50 percent
more quickly than was previously assumed. That is because earlier
computer models calculated the impacts of a warming atmosphere on
a relatively static biosphere. But when they factored in the warming
that has already taken place, they found that the rate of change is com-
pounding. Their projections show that many of the world’s forests will
begin to turn from sinks to sources—dying off and emitting carbon—
by around 2040.
The other study, from the energy side, is equally troubling. Three
years ago, a team of researchers reported in the journal Naturethat
unless the world obtains half its energy from noncarbon sources by
2018, we will see an inevitable doubling—and possible tripling—of
INTRODUCTION
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