James E. Hansen, director of NASA's Goddard Institute for Space Studies (GISS) and an adjunct professor at Columbia University's Earth Institute, has announced he will retire as director of GISS this week to devote more time to his campaign to cut global carbon emissions.
"Jim Hansen is a one of the true giants of climate science," said Earth Institute director Jeffrey Sachs. "His pioneering work has enabled humanity to understand the planet's climate dynamics, to interpret the lessons of the Earth's long history, and to peer ahead to the perils we face if we continue on the business-as-usual path. When humanity finally wakes up to the profound risk facing us — and it will — we will owe humanity's future wellbeing to Jim Hansen's brilliance, boldness, and clarity of thought and expression."
Hansen came to GISS in 1967 as a post-doctoral researcher and became director in 1981, making him the longest serving director in the institute's history. In recent years, he took on an activist role in efforts to slow climate change, pushing government to impose limits on carbon emissions and rallying opposition to the energy-intensive extraction of oil from Canada's tar-sands.
"If we burn even a substantial fraction of the fossil fuels, we guarantee there's going to be unstoppable changes in the climate of the earth," he told the New York Times, which broke the news of his retirement on Tuesday. "We're going to leave a situation for young people and future generations that they may have no way to deal with."
Hansen was trained in physics and astronomy in James Van Allen's space science program at the University of Iowa, receiving his bachelor's degree with highest distinction in physics and mathematics, master's degree in astronomy, and Ph.D. in physics in 1967. Except for 1969, when he was a National Science Foundation post-doctoral student at the Leiden Observatory in Holland, Hansen spent his professional career at GISS. Hansen was a visiting student at the Institute of Astrophysics, University of Kyoto and Department of Astronomy, Tokyo University, Japan from 1965-1966.
In his early research, Hansen used telescopic observations of Venus to describe the physical properties of the cloud and haze particles that veil Venus. Since the mid-1970s, he has focused on studies and computer simulations of Earth's climate, working to understand the climate system and human impacts on global climate. Hansen's testimony before Congress in 1988 helped to raise broad public awareness of global climate change and its consequences for humanity.
His research has closely tracked the development of sophisticated satellite platform measurements, such as the terrestrial radiation budget, ozone and weather-related data, and the need for increasingly sophisticated atmospheric models to assess and evaluate the information content and utility of these measurements. Current climate models are now able to reproduce the historical temperature record over the past century and to make climate change predictions for the future, keeping pace with NASA's measurements of solar energy variations, sea level change and polar ice loss with unprecedented precision and accuracy.
Hansen's climate analyses have been based not only on the very basic physics that goes into climate model design, but on the detailed studies of the geological ice core and isotope records that are used to constrain and confirm climate model sensitivity. In recent years Hansen has drawn attention to the danger of passing climate tipping points, producing irreversible climate impacts that would create a different planet from the one on which civilization developed.
"Jim has been at the center of almost every important conceptual advance in climate science in the last few decades and has a track record of successful predictions that is second to none," said climate scientist Gavin Schmidt, deputy chief at GISS, which is part of the Earth Institute.
Peter Hildebrand, director of the Earth Sciences Division at NASA's Goddard Space Flight Center in Greenbelt, Md., will serve as interim director until a new director is named.
Hansen has received many honors worldwide. He was elected to the National Academy of Sciences in 1995; received the Heinz Award for the Environment, and the American Geophysical Union's Roger Revelle Medal in 2001; the World Wildlife Federation's Conservation Medal from the Duke of Edinburgh; and was designated by Time Magazine as one of the "World's Most Influential People" in 2006. In 2007, Hansen received the Dan David Prize in the field of Quest for Energy and the Leo Szilard Award of the American Physical Society for Outstanding Promotion and Use of Physics for the Benefit of Society. In 2009, he was awarded the American Meteorological Society's Carl-Gustaf Rossby Research Medal, and the Sophie and Blue Planet Prizes in 2002. In 2012, he was awarded the Stephen Schneider Award for Climate Science Communications by Climate One, an initiative of the Commonwealth Club of San Francisco. He is also the author of the 2009 book, "Storms of My Grandchildren."