Years Later, Climatologist Renews His
Call for Action
Jun 23, 2008 - Andrew C. Rivkin - The New
York Times
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Oscar Hidalgo for The
New York Times
James E. Hansen, a NASA climate expert,
used a pair of cardboard dice 20 years ago to explain
that humans were tipping the odds of harmful climate
change by adding greenhouse gases to the atmosphere.
He displays one die in his Manhattan office. |
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Twenty years ago Monday, James E. Hansen,
a climate scientist at NASA, shook Washington and the world
by telling a sweating crowd at a Senate hearing during a
stifling heat wave that he was “99 percent” certain that
humans were already warming the climate.
“The greenhouse effect has been detected,
and it is changing our climate now,” Dr. Hansen said then,
referring to a recent string of warm years and the accumulating
blanket of heat-trapping carbon dioxide and other gases
emitted mainly by burning fossil fuels and forests.
To many observers of environmental history,
that was the first time global warming moved from being
a looming issue to breaking news. Dr. Hansen’s statement
helped propel the first pushes for legislation and an international
treaty to cut emissions of greenhouse gases. A treaty was
enacted and an addendum, the Kyoto Protocol, was added.
Even as the scientific picture of a human-heated
world has solidified, emissions of the gases continue to
rise.
On Monday, Dr. Hansen, 67, plans to give a
briefing organized by a House committee and say that it
is almost, but not quite, too late to start defusing what
he calls the “global warming time bomb.” He will offer a
plan for cuts in emissions and also a warning about the
risks of further inaction.
“If we don’t begin to reduce greenhouse gas
emissions in the next several years, and really on a very
different course, then we are in trouble,” Dr. Hansen said
Friday at NASA’s Goddard Institute for Space Studies in
New York, which he has directed since 1981. “Then the ice
sheets are in trouble. Many species on the planet are in
trouble.”
In his testimony, Dr. Hansen said, he will
say that the next president faces a unique opportunity to
galvanize the country around the need for a transformed,
nonpolluting energy system. The hearing is before the House
Select Committee on Energy Independence and Global Warming.
Dr. Hansen said the natural skepticism and
debates embedded in the scientific process had distracted
the public from the confidence experts have in a future
with centuries of changing climate patterns and higher sea
levels under rising carbon dioxide concentrations. The confusion
has been amplified by industries that extract or rely on
fossil fuels, he said, and this has given cover to politicians
who rely on contributions from such industries.
Dr. Hansen said the United States must begin
a sustained effort to exploit new energy sources and phase
out unfettered burning of finite fossil fuels, starting
with a moratorium on the construction of coal-burning power
plants if they lack systems for capturing and burying carbon
dioxide. Such systems exist but have not been tested at
anywhere near the scale required to blunt emissions. Ultimately
he is seeking a worldwide end to emissions from coal burning
by 2030.
Another vital component, Dr. Hansen said,
is a nationwide grid for distributing and storing electricity
in ways that could accommodate large-scale use of renewable,
but intermittent, energy sources like wind turbines and
solar-powered generators.
The transformation would require new technology
as well as new policies, particularly legislation promoting
investments and practices that steadily reduce emissions.
Such an enterprise would be on the scale of
past ambitious national initiatives, Dr. Hansen said, like
the construction of the federal highway system and the Apollo
space program.
Dr. Hansen disagrees with supporters of “cap
and trade” bills to cut greenhouse emissions, like the one
that foundered in the Senate this month. He supports a “tax
and dividend” approach that would raise the cost of fuels
contributing to greenhouse emissions but return the revenue
directly to consumers to shield them from higher energy
prices.
As was the case in 1988, Dr. Hansen’s peers
in climatology, while concerned about the risks posed by
unabated emissions, have mixed views on the probity of a
scientist’s advocating a menu of policy choices outside
his field.
Some also do not see such high risks of imminent
climatic calamity, particularly disagreeing with Dr. Hansen’s
projection that sea levels could rise a couple of yards
or more in this century if emissions continue unabated.
Dr. Hansen is a favorite target of conservative
commentators; on FoxNews.com, one called him “alarmist in
chief.” But many climate experts say Dr. Hansen, despite
some faults, has been an essential prodder of the public
and scientific conscience.
Jerry Mahlman, who recently retired from a
long career in climatology, said he disagreed with some
of Dr. Hansen’s characterizations of the climate problem
and his ideas about solutions. “On the whole, though, he’s
been helpful,” Dr. Mahlman said. “He pushes the edge, but
most of the time it’s pedagogically sound.”
Dr. Hansen said he was making a new public
push now because the coming year presented a unique opportunity,
with a new administration and the world waiting for the
United States to re-engage in treaty talks scheduled to
culminate with a new climate pact at the end of 2009.
He said a recent focus on China, which has
surpassed the United States in annual carbon dioxide emissions,
obscured the fact that the United States, Britain and Germany
are most responsible for the accumulation of greenhouse
gases.
Dr. Hansen said he had no regrets about stepping
into the realm of policy, despite much criticism.
“I only regret that we haven’t gotten the
story across as well as it needs to be,” he said. “And I
think we’re running out of time.”
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