1962)[1] is an American scientist, renewable energy expert, and former government figure.

Kammen is noted as a coordinating lead author for the Intergovernmental Panel on Climate Change, which won the 2007 Nobel Peace Prize for their report, Climate Change 2007, assessing man-made global warming.

[2] In 1998, Kammen was elected a permanent fellow of the African Academy of Sciences, and in 2007 received the Distinguished Citizen Award from the Commonwealth Club of California.

[7] He resigned from this position in 2017, citing what he believed to be President Trump's failure to denounce white supremacists and neo-Nazis.

[8] His August 23, 2017, resignation letter went viral, as netizens noticed that the first letter of each paragraph spelled out I-M-P-E-A-C-H.[9] Kammen has been mentioned as a potential Secretary of Energy in a Joe Biden administration.