The overwhelming majority of scientists agree: earth's temperature has risen
during the past century But is it due to man's use of fossil fuel energy? And if so, how can we prevent the catastrophic results that some
scientists predict if global warming continues?
In "What's Up with the Weather?" NOVA and FRONTLINE join forces to investigate
the science and politics of one of the most controversial issues of the 21st
century: the truth about global warming.
The program charts how scientists agree on many key issues underlying global
warming: so-called "greenhouse gases" such as carbon dioxide (CO2)
and methane trap radiation from the sun, thereby warming the earth. Worldwide
measurements -- taken from trees, ice cores, coral reefs and air--show
the concentration of these gases has increased by one-third since the
Industrial Revolution. And, scientists also agree that the earth's surface
temperature has increased one degree Fahrenheit over the 20th century (see graphs).
But a fierce debate centers on whether this warming is a natural phenomenon or
the result of man's burning of fossil fuels like coal and oil, which increase
the amount of CO2 in the atmosphere. This NOVA/FRONTLINE report
interviews leading scientists, policymakers and fuel industry
representatives with sharply different viewpoints.
Those who believe human activity is contributing to global warming say the
problem is compounded because most people are unaware of their own role in
global warming--due to their dependency on fossil fuels for energy. It's a
dependency which could affect the planet's fate, say greenhouse proponents.
"If the planet warms too much, we are going into unknown territory," says
Tom Wigley, senior scientist for the National Center for Atmospheric
Research (NCAR). "If we were to warm the world by five degrees, I strongly
believe that large parts of the Antarctic ice sheet would flow into the ocean,
melt, and cause sea level to rise by many meters."
That could mean disastrous flooding of coastal areas. Other scientists
predict intense storms, droughts, famines, the spread of infectious diseases,
and the wholesale destruction of species and habitats.
But others aren't so sure. A direct connection between man and the earth's
warming has yet to be proven, say scientists such as Fred Singer, an
atmospheric physicist. He suggests that the earth's increased temperature is
due to natural causes and argues that increased levels of CO2 in
the atmosphere are actually a good thing.
Who's right? Scientists on both sides of the global warming debate are building sophisticated computer models to predict various
climatic scenarios. But, the slightest change in one variable produces a range
of possible climatic outcomes, resulting in even more speculation about global
warming's real impact.
This scientific uncertainty fuels political uncertainty, as the United States
struggles to decide what, if any, action to take. The 1997 Kyoto Protocol
commits the United States and other industrial nations to significant cutbacks
in greenhouse gas emissions. Critics argue that the
cutbacks will harm the U.S. economy, particularly since developing nations have
not agreed to cut their own growing use of fossil fuels.
"What Up With the Weather" concludes with a look at the possibilities--and
challenges--in turning to non-carbon energy sources,
including nuclear power
and "renewable energies." Scientists also hold out hope for developing
unimagined new technologies that will replace fossil fuels.
"There comes a point when you can't escape the idea that you're having serious
climatic consequences," says Richard Somerville of the Scripps
Institution of Oceanography. "The issue becomes one of whether we get wise
before that day or whether we have to wait for some perhaps quite unanticipated
climate surprise that wakes us all up."
> the debate
> carbon diet
> stories in ice
> beyond fossil fuels
> water world
> program excerpt
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