John L. Hall

In 2015, Hall signed the Mainau Declaration 2015 on Climate Change on the final day of the 65th Lindau Nobel Laureate Meeting. The declaration was signed by a total of 76 Nobel Laureates and handed to then-President of the French Republic, François Hollande, as part of the successful COP21 climate summit in Paris.

Hall is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W. Bush in May of 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy’s Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.

Born in Denver, Colorado, Hall holds three degrees from Carnegie Institute of Technology, a B.S. in 1956, an M.S. in 1958, and a Ph.D. in 1961. He completed his postdoctoral studies at the Department of Commerce's National Bureau of Standards, now the National Institute of Standards and Technology (NIST), where he remained from 1962 until his retirement in 2004. He has lectured at the University of Colorado Boulder since 1967.

John Lewis "Jan" Hall (born August 21, 1934) is an American physicist, and Nobel laureate in physics. He shared the 2005 Nobel Prize in Physics with Theodor W. Hänsch and Roy Glauber for his work in precision spectroscopy.