Harold ("Hal") Warren Lewis (born October 1, 1923[1] – May 26, 2011[2]) was an American Emeritus Professor of Physics and former department chairman at the University of California, Santa Barbara (UCSB).

In 2010, after 67 years of membership, he resigned from the American Physical Society, citing what he saw as "the global warming scam, with the (literally) trillions of dollars driving it”.

He earned a master's degree from the University of California, Berkeley, from 1943 to 1944 before joining the Navy, where he served in World War II as an electronics technician.

[10] In his 1990 book Technological Risk, Lewis wrote that "all models agree that the net effect" of increasing greenhouse gases "will be a general and global warming of the earth; they only disagree about how much.

Reducing the effects, including significant sea level rise, would "require global cooperation and sacrifice now, to avert something far in the future, and a conjectural something at that.

Lewis said that he had joined the APS 67 years previously, when it was "as yet uncorrupted by the money flood" which he said had "become the raison d’être of much physics research, the vital sustenance of much more, and it provides the support for untold numbers of professional jobs."

[11] On 12 October, the climate change denialist think-tank The Global Warming Policy Foundation announced that Lewis had agreed to join their "Academic Advisory Council".

[12] The APS completely rejected Lewis's claims of "scam" and "fraud", stating that virtually all reputable scientists were agreed on observations of human caused global warming.