NEW YORK, April 2, 2013 /PRNewswire-USNewswire/ -- James E. Hansen, director of NASA's Goddard Institute for Space Studies (GISS) in New York has announced he is retiring as the GISS director and leaving government service. 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 selected through a competitive process. (Logo: http://photos.prnewswire.com/prnh/20081007/38461LOGO) Hansen is the longest serving director in the institute's history. He came to GISS in a post-doctoral appointment in 1967, became a federal employee at GISS in 1972, and became director in 1981. "It has been a great honor to work for NASA -- I still remember my excitement while driving from Iowa to the Goddard Institute in 1967 -- and now I look forward to working full-time on climate science and its implications for policy," said Hansen. "Throughout his career, Jim Hansen has demonstrated the spirit of an American pioneer. He has pushed forward the frontier of our knowledge of Earth's climate system and of the impacts that humanity is having on Earth's climate," said Nicholas E. White, director of the Sciences and Exploration Directorate at NASA Goddard. 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 extract detailed information on 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 the broad public awareness of the global climate change as an important issue for us all.