James Hansen

Please note, this page has been archived as of 2011 and will not be updated. 

"Stabilizing climate is a moral issue, a matter of intergenerational justice."

J. Hansen

James Hansen is one of the world's most prominent and influential climate scientists, chief climate scientist at the NASA Goddard Institute for Space Studies (GISS) in New York, and adjunct professor at the Department of Earth and Environmental Sciences at Columbia University.

The main area of GISS' scientific research is the prediction of atmospheric and climate change during the 21st Century, combining analysis of global datasets with modelling of atmospheric, land surface, and oceanic processes. Hansen has led GISS since 1981.

He was educated at the University of Iowa, where he obtained a BA in physics and mathematics, an MSc in astronomy and in 1967 a PhD in Physics focusing on cloud formation on Venus. After university, he went directly to work at GISS.

Hansen's main research area is the development of global climate models which simulate current climate patterns and create projections of human impacts on future climate. He has published more than 140 peer-reviewed papers on climate science.

Raising awareness of climate change

Hansen was one of the first climate scientists to warn about the dangers of global warming. In testimony given to the US Congress in 1988 he said: "It was 99 percent certain that the warming trend was not a natural variation but was caused by a buildup of carbon dioxide and other artificial gases in the atmosphere."

He also provided three computer model projections of global temperatures based on varying future levels of C02 emissions. Hansen's scenario A overestimated temperature rise. However, there is disagreement among scientists as to whether scenario B or scenario C forecasted temperature rises more accurately.

Hansen's testimony has been regarded as pivotal in bringing climate change to the world's attention. Shortly afterwards Hansen chose to stop working through the media, stating: "I don't consider myself a communicator, I'm a scientist… I think that's what I do best."

Hansen returned to advocacy on climate issues in 2004, driven by his belief that "there was a gap between what was understood by the relevant scientific community, and what was known by the public - people who need to know". Since then Hansen has been a vocal advocate for urgent action on climate change, which he describes as an 'emergency'.

In 2006 Hansen claimed the Bush administration had tried to prevent him speaking about the necessity of reducing greenhouse gas emissions.


Political activism


Hansen is a vocal opponent of the continued use of coal as a fuel, and has called for the USA to abolish the practice of 'mountaintop-removal' for coal mining. He has written to world leaders to ask them to place a moratorium on new coal-fired power plants. He claims that "coal is the single greatest threat to civilization and all life on our planet."


He has been arrested twice while taking part in civil disobedience against the continued use of coal as a fuel. In 2011, he appeared as a witness at the trial of 20 environmental activists who intended to shut down a coal power plant at Ratcliffe-on-Soar, having previously appeared as an expert witness in the trial of six Greenpeace campaigners who were acquitted of similar charges.

Hansen defended the action as understandable, saying: "The fact that we continue to burn more coal and build more coal plants shows governments are not telling the truth."

In an essay on his activism he wrote:

"To the young people I say: stand up for your rights - demand that the government be honest and address the consequences of their policies… I look forward to standing with young people and their supporters, helping them develop their case, as they demand their proper due and fight for nature and their future. I guess that makes me an activist."

Hansen has been criticised for his advocacy and campaigning activities, and his relevance has been questioned. Joe Romm, author of the Climate Progress blog has said of Hansen's campaigning that: "The right wing loves what he's doing". He has been accused of having close relationships with the Democratic party. However, in a statement of political inclinations he declared "I do not have close political ties to a political party."

Hansen advocates a carbon tax and has opposed the introduction of 'cap and trade' systems in the USA.

In 1996 Hansen was elected as a member of the US National Academy of Sciences. He has received numerous awards for his work, including the John Heinz Environment Award, the Roger Revelle Medal from the American Geophysical Union (AGU) and the Carl-Gustaf Rossby Research Medal from the American Meteorological Society. In 2010, together with Bob Watson, Hansen was awarded the Blue Planet Prize, an international environment award dubbed the 'Japanese Nobel Prize'.

In 2009 Hansen published his first book, Storms of My Grandchildren.

Please note - This material was last updated on 3/7/11 and has since been archived.