Global warming debate heats up 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." 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."....