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Dr. James E. Hansen

Climate Scientist
Dr. James E. Hansen

On June 23, 1988, James Hansen, the then-director of NASA’s Institute for Space Studies, testified before the Senate Energy and Natural Resources Committee. He stated that there was a strong cause and effect relationship between observed temperatures and human emissions into the atmosphere; that “the greenhouse effect is here.” The following morning the New York Times headline read, “Global Warming Has Begun.” Over the decades since, Hansen has used his stature as NASA’s top climate scientist to convincingly argue that climate change is the work of humans, and that “global warming isn’t a prediction. It is happening.”

Hansen was born March 29, 1941, in western Iowa, one of seven children. He showed an interest in science from a young age, and was persuaded as a college senior to take the physics graduate school qualifying exam by a professor. Hansen subsequently received his degrees in physics, astronomy, and mathematics at the University of Iowa, studying at Dr. James Van Allen’s space science program.

Upon graduation, he went to work directly at the NASA Goddard Institute for Space Studies where he studied the composition of the atmosphere of Venus. But after a decade of research he switched his focus to the changing atmosphere of another planet: Earth.  Since publishing his seminal studies on the effects of greenhouse gases in 1981, and following his Senate testimony, Hansen has steadily ratcheted up the pressure on public officials to take his warnings seriously. He spoke out against the Bush administration’s attempts to mute his warnings about the urgent need to address climate change, and has implored President Obama to reject the Keystone XL pipeline.

Hansen describes his transformation from a pure scientist to a “witness”—what writer Robert Pool described in a May 1990 issue of Science magazine as “someone who believes he has information so important that he cannot keep silent."  As he writes in his book, he didn’t want his grandchildren, sometime in the future, to look back and say, “Opa understood what was happening, but he did not make it clear.” Hansen also takes seriously one of the central tenets of NASA’s former mission statement to “understand and protect our home planet.”

In 1996, Hansen was elected to the National Academy of Sciences. He directed the NASA Goddard Institute for Space Studies in New York City from 1981 to 2013 and is Adjunct Professor of Earth Sciences at Columbia University’s Earth Institute. Hansen has received numerous prizes for his work, including the AASA Award for Scientific Freedom and Responsibility for his “courageous and steadfast advocacy in support of scientists' responsibilities to communicate their scientific opinions and findings openly and honestly on matters of public importance,” the Carl-Gustaf Rossby Research Medal, which is the highest honor bestowed by the American Meteorological Society, and the 2010 Blue Planet Prize, considered to be Japan’s equivalent to the Nobel Prize. In 2012, Foreign Policy named Hansen one of its Top 100 Global Thinkers “for sounding the alarm on climate change, early and often.”

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Events with this presenter

International Speaker Series (2013)

Avoiding Climate Catastrophe: Putting Science Before Politics

Dr. James E. Hansen

Avoiding Climate Catastrophe: Putting Science Before PoliticsNamed one of Foreign Policy's 100 Top Global Thinkers in 2012, legendary climate scientist James E. Hansen, the maverick former head of NASA’s Goddard Institute of Space, was the first to issue the clearest warning of about the dangers of global warming. Read More ››

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