Global warming debate heats up

WASHINGTON – While one NASA scientist says man-made catastrophic climate change will cause an apocalypse, another says hysterical pronouncements about carbon dioxide emissions are unwarranted and overblown.

James Hansen, a political ally of former Vice President Al Gore, who has popularized the notion the planet is on the verge of calamitous changes as a result of higher levels of CO2 in the atmosphere, says: "We do have a planetary emergency, but it is difficult because you don't see that much happening. … If we don't bring this under control, we're going to destroy creation."

Roy Spencer

Hansen told a Kansas wind and renewable energy conference last month global warming inevitably will bring about droughts, melting ice caps, rising sea levels and mass extinctions.

But Roy Spencer, U.S. science team leader for NASA's collection of satellite temperature data and principal research scientist at the University of Alabama at Huntsville's Earth System Science Center, says the climate system is not as sensitive to increasing concentrations of carbon dioxide as computer models suggest.

This would mean "that we have little to worry about in the way of man-made global warming and associated climate change," Spencer said in testimony to the U.S. Senate Environment and Public Works Committee this summer. "And, as we will see, it would also mean that the warming we have experienced in the last 100 years is mostly natural. Of course, if climate change is natural then it is largely out of our control, and is likely to end – if it has not ended already, since satellite-measured global temperatures have not warmed for at least seven years now."

Spencer is author of the book, "Climate Confusion." He says mankind will one day look back at the global warming scare "as a gigantic false alarm."

Still, despite an ever-increasing number of scientists supporting Spencer's position, many politicians – and some scientists – insist the debate about global warming is over, that it is a matter of settled science.

In fact, Hansen has claimed those who question his conclusions "are guilty of crimes against humanity and nature."

Some believe he long ago crossed the line from objective scientist to strident political activist. Last year, for instance, he told an interviewer: "I tell young people that they had better start to act up. Because they are the ones that will suffer the most. Many of the changes will take time, but we're setting them in motion now. We're leaving a situation for our children and grandchildren which is not of their making, but they're going to suffer because of it. So I think they should start to act up and put some pressure on their elders, and on legislatures, and begin to get some action."

Hansen presides over an $18 billion federal budget and has been known for making his strong political statements "on company time."

While Hansen and other proponents of man-made catastrophic global warming theories often accuse skeptics of being influenced by industry grants, Hansen himself was the recipient of $250,000 from Heinz Foundation, directed by the wife of Sen. John Kerry, D-Mass., awarded for his work on the subject in 2001. Why did he get the grant? The foundation explained: "It was Dr. Hansen who, in the sweltering, drought-scorched summer of 1988, went where few scientists were willing to go-before Congress, to explain just how serious the potential for global warming truly was." Hansen also reportedly acted as a consultant on Al Gore's slide show that inspired his movie, "An Inconvenient Truth." He also promoted the movie in New York.

Meanwhile, Spencer says his researchers have recently "stumbled upon clear and convincing observational evidence of particularly strong negative feedback (low climate sensitivity to carbon dioxide levels) from our best satellite instruments. That evidence includes our development of two new methods for extracting the feedback signal from either observational or climate model data, a goal which has been called the 'holy grail' of climate research."

It seems there is a debate, after all, and as global temperatures seem to stabilize, that debate is heating up.

See transcript of Spencer's complete testimony.