Jan. 24, 2008
Q & A: Professor James Hansen
Long before Al Gore’s Nobel Peace Prize, before the Kyoto Protocol,
compact fluorescent light bulbs or hybrid cars, James Hansen was
sounding the alarm on greenhouse gas emissions and bringing the
world’s attention to the issue of climate change.
It was August 1981 when the journal Science published Hansen’s
galvanizing paper, which concluded that carbon dioxide in the
atmosphere would lead to global warming faster than prior predictions.
Professor James Hansen
Those 10 pages, riddled with equations, graphs and charts and bearing
the bland title “Climate Impact of Increasing Atmospheric Carbon
Dioxide,” became the shot heard ‘round the world in scientific circles.
Its message has been reverberating ever since, ricocheting through
the political landscape and becoming a clarion call for environmental
activists and average citizens alike.
Hansen has taken more than his share of heat for his climate warnings.
He has complained of being muzzled by presidential administrations,
Democrat and Republican alike, who didn’t appreciate his conclusions,
as they contradicted the nation’s energy policy. His 2006 battle on that
score is the subject of a book published last month called Censoring
Science: Inside the Political Attack on Dr. James Hansen and the Truth
of Global Warming, by Mark Bowen.
Born and educated in the Midwest, Hansen lives and works on the
Upper West Side, heading the NASA Goddard Space Institute for Space Studies (GISS), which is affiliated with Columbia. He also teaches earth and
environmental sciences at the University.
Q. The 1981 analysis in the journal Science was one
of the first public discussions about an increase
in global temperature. Did you have any inkling how
important your findings would be?
A. The broad long-term implications were pretty
obvious. I worked on it more than a year to get it into
a shape that Science would accept, submitting it at least three
times, each time cutting the length about 15 percent, finally getting
it to a length they would accept, even though it was twice what
the editor kept saying was their size limit. I also sent it to
Walter Sullivan, The New York Times reporter, who wrote an
article on the front page, which got me in trouble with some
colleagues and [the Department of Energy].
Q. It seems that you were among the few scientists
talking about climate change for a long time. What
was it like to be out there alone?
A. That’s not true. There were a lot of scientists
working on climate. There were different threads,
different approaches. For example, global modeling along the
lines that GFDL [Geophysical Fluid Dynamics Laboratory],
NCAR [National Center for Atmospheric Research] and GISS
pursued. There were paleo-climate studies of the history of
the Earth’s climate, and there were observations of on-going
climate changes via satellites and other methods. But not as
much interactions among these [researchers] as you would
like. Now we have reached the point where you need to have
your fingers into all of these if you want to develop insight
quickly into how climate works and what the consequences
of human forcings will be.
Q. A forcing is described as a disruption created
by outside action. What kind of forcing are you
referring to here?
A. A natural forcing is a change in the sun’s brightness.
The largest human-made forcing is change of the
amount of greenhouse gases in the air, gases that absorb heat
radiation and make the planet warmer.
Q. Usually the media seizes on stories with
doomsday scenarios. Why do you think it took so
long for people to appreciate the danger of climate change?
A. Well, business-as-usual is doomsday. But the things
that need to be done to avoid business as usual have
many other benefits… Unfortunately, if special interests
prevent us from taking an energy path that does not put all
the fossil fuel carbon dioxide into the air, we will get at least
part of doomsday. I think that we still have time to avoid that,
but just barely.
Q. Were you surprised at the government’s reaction
to your findings?
A. Well, not after my experience with DOE in 1981. They
made it very clear that the government did not want to
hear results that it did not want to hear.
Q. There is so much talk about climate change these
days. Is the conversation where it should be?
A. No, far from it. The special interests, with financial
interests that they feel would be threatened, have
succeeded in muddying the waters so much that the sensible
actions, which would solve the problem and have many
other benefits, are not being taken. Unfortunately, this is
because special interests in Washington have undue sway
over politicians. We should have statesmen in Washington—instead we have politicians.
Q. Did you ever consider leaving NASA to do
research somewhere that would be more accepting
of your conclusions?
A. No, NASA is the perfect place, because it has the
capability to get much of the most critical data—and
a can-do attitude.
Q. You’ve estimated that temperatures on Earth will
be two to three degrees Celsius warmer at the end
of the 21st century than they are now. That may not sound
like a serious change to the layman. Can you explain why
it is important?
A. I do not think that global temperature will be two
to three degrees Celsius warmer, because if it is,
that is doomsday. I believe that it is still possible to wake people up, and we can move on to the world beyond fossil
fuels. A warming that large would set us on a path toward sea
level tens of meters higher, at least a few meters higher this
century, with a continually changing coastline. That would
be catastrophic. It would also spell the end for a substantial
fraction of species on the planet.
Q. Do you have specific solutions to reduce
greenhouse gas emissions?
A. The phase-out of coal use over the next 25 years,
except where carbon dioxide is captured, by itself
would keep carbon dioxide below 425 parts per million, and
warming less than one degree Celsius. That’s not enough, but
it’s a large fraction of the solution.
Q. Can individual actions make a difference, or
is climate change the kind of problem that can be
solved only through government action?
A. By far, the most important requirement is government
leadership. What the individual can do is demand
that. As long as we let people who are under the heavy thumb
of special interests run the country, individual actions are
meritorious, but they cannot solve the problem.
- Interviewed by Bridget O’Brian