James Hansen

Dr. James E. Hansen

Dr. James E. Hansen is the lead climate scientist and director of the NASA Goddard Institute for Space Science. His primary interests are radiative transfer and climate modeling.

History

He was born in Iowa in 1941. Hansen studied at the University of Iowa under James Van Allen.

On June 23, 1988, as director of the NASA Institute for Space Studies, Hansen testified before the House of Representatives that there was a strong "cause and effect relationship" between observed temperatures and human emissions into the atmosphere. This bold statement garnered him a front-page story on the New York Times and national attention.

Convictions

• A global tipping point will be reached in 10 years if levels of greenhouse gases like methane and CO₂ are not reduced. Global warming at this point becomes unstoppable. [1].
• Global warming is 0.5–0.75 °C in the past century, and about 0.3 °C or more in the last 25 years
• climate sensitivity to CO₂ doubling is 3±1 °C

Publications

In 2000 he authored a paper called Global warming in the twenty-first century: an alternative scenario[2] in which he presents a more optimistic way of dealing with global warming focusing on non-CO₂ gases and black carbon in the short run, giving more time to make reductions in fossil fuel emissions. He notes that warming observed to date is largely due to non-CO₂ gases. This is because CO₂ warming is offset by climate-cooling aerosols emitted with fossil fuel burning and because non-CO₂ gases, taken together, are responsible for roughly 50% of greenhouse gas warming.

Thus, assuming only that our estimates are approximately correct, we assert that the processes producing the non-CO2 GHGs have been the primary drive for climate change in the past century.

In 2004 he wrote a paper called Defusing the global warming time bomb [3], containing:

At present, our most accurate knowledge about climate sensitivity is based on data from the earth’s history, and this evidence reveals that small forces, maintained long enough, can cause large climate change.

Human-made forces, especially greenhouse gases, soot and other small particles, now exceed natural forces, and the world has begun to warm at a rate predicted by climate models.

The stability of the great ice sheets on Greenland and Antarctica and the need to preserve global coastlines set a low limit on the global warming that will constitute “dangerous anthropogenic interference” with climate.

Halting global warming requires urgent, unprecedented international cooperation, but the needed actions are feasible and have additional benefits for human health, agriculture and the environment.

He also commented on the past usefulness of extreme warming scenarios to obtain political and policy actions on page 30 here:[4]

Opposing Greenhouse Skeptics

He has taken an active part in the debate around global warming, and has argued that:

Some "greenhouse skeptics" subvert the scientific process, ceasing to act as objective scientists, rather presenting only one side, as if they were lawyers hired to defend a particular viewpoint. But some of the topics focused on by the skeptics are recognized as legitimate research questions, and also it is fair to say that the injection of environmental, political and religious perspectives in midstream of the science research has occurred from both sides in the global warming debate.

—[5]

He has charged that Patrick Michaels misrepresented his work to Congress [6] in 1998 , and lists a number of areas where he disagrees with Richard Lindzen [7].

In 1998 Hansen argued that uncertainties in climate forcings have supplanted global climate sensitivity as the predominant issue [8]; the paper is discussed here.

In 2005 and 2006, Hansen claimed in interviews with the Washington Post[9] and the New York Times[10] that NASA administrators have tried to influence his public statements about the causes of climate change. Hansen claims that NASApublic relations staff were ordered to review his public statements and interviews after a December 2005 lecture at the American Geophysical Union in San Francisco.

In response to Michael Crichton's novel State of Fear, which attempted to disprove global warming, Hansen offerred a rebuttal. It centered on a claim made by Crichton that Hansen in 1988 made predictions about global warming that ended up being "300% too high", claiming that Crichton and others cherry-picked data from his research [11].

Rewriting The Science

James Hansen has also appeared on 60 Minutes[12] claiming that the White House has been editing climate related press releases reported by federal agencies to make global warming seem less threatening. He is unable to speak "freely", without the backlash of other government officials. "In my more than three decades in the government I've never witnessed such restrictions on the ability of scientists to communicate with the public," he says.

He makes claims that the tipping point (also known as the runaway effect) is upon us, and that if in 10 years the human population is unable to reduce greenhouse gases, that the oceans might rise as much as 10 feet by 2100.

References

• 29 Jan 2006 Hansen in the New York Times
• 13 Feb 2006 Time Magazine Cover Story: The Political Science Test

External links

• Dr. James E Hansen's Homepage
• NASA GISS Biography
• The Global Warming Debate by James Hansen
• "Scientist Inspires Anger, Awe for Challenges on Global Warming" Washington Post
• "Climate Expert Says NASA Tried to Silence Him" New York Times
• "NASA and Global Warming" Audio Interview with WBUR OnPoint
• Soviet style "minder(s)" are being used on American scientists

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