Walt joined the Packard Foundation in 2006 and is the Vice President of Environment and Science.

Prior to joining the Packard Foundation, he was a consulting professor at Stanford University from 2005 to 2006. Walt was responsible for the creation of the Millennium Ecosystem Assessment, which he directed from 1998 until the release of the findings in March 2005. From 1992 to 1998, he was vice president of the World Resources Institute in Washington D.C.

Walt is on the Board of the Climate and Land Use Alliance and Energy Foundation China, and chairs the Board of Climate Breakthrough. He previously was a member of the Biodiversity and Ecosystem Services working group of the President’s Council of Advisors on Science and Technology (PCAST); the Board of “The Economics of Ecosystems and Biodiversity” (TEEB) project; the governing committee of the Policy and Global Affairs Division of the National Research Council; the Board of the Society for Conservation Biology; and the Board of Editors of Ecological Applications, PLOS-Biology, and Ecosystems. He has published more than 90 papers and is the first author of five books.

Walt earned his Ph.D. in zoology (ecology and evolutionary biology) from the University of Washington and his B.A. in zoology from the University of California at Berkeley.