ABC News’s John Stossel, most famous for his “give me a break” tag line, is mad at Al Gore for saying the debate on global warming is over. To prove the former VP wrong, he interviewed several scientists who have a contrary view, including John Christy and Roy Spencer who won NASA’s Medal for Exceptional Achievement for figuring out how to get temperature data from satellites.

“We all agree that it’s warmed,” Spencer told Stossel. “The big question is, and the thing we dispute is, is it because of mankind?”

In fact, research indicates that Greenland’s temperatures rose 50 percent faster in the 1920s and reached higher average temperatures in the 1930s and 1940s than today’s temperatures. Some scientists also argue that global warming might be caused by changes in the sun, or ocean currents, or changes in cloud cover.

“The debate is not over,” concludes Stossel.