Ivar Giaever resigned from the American Physical Society after the organization, which has 48,000 members, adopted a policy statement that states: "The evidence is incontrovertible: global warming is occurring."
"Incontrovertible is not a scientific word," the U.S.-based Giaever, a Norwegian who shared the 1973 Nobel award for physics, told Britain's The Sunday Telegraph.
"Nothing is incontrovertible in science."
Giaever, 82, was one of President Barack Obama's leading scientific supporters during the 2008 president election campaign, but has since criticized the president over his stance on global warming. Giaever joined more than 100 scientists in an open letter to Obama saying, "We maintain that the case for alarm regarding climate change is grossly overstated."
"Global warming has become a new religion," Giaever said. "We frequently hear about the number of scientists who support it. But the number is not important: only whether they are correct is important.
"We don't really know what the actual effect on the global temperature is. There are better ways to spend the money."