Images of killer hurricanes like Katrina have long been used as a powerful symbol for catastrophic global warming. But that might change, now that some influential scientists are beginning to take a second look at that link. Kerry Emmanuel of MIT, who used to be one of the leading proponents of a link between global warming and stronger hurricanes, just published research that suggests hurricane frequency and intensity may not rise substantially, even in a much warmer world. With meteorologist Tim Knutson of NOAA also recently weighing in with a study saying warmer oceans could actually reduce the number of Atlantic hurricanes making landfall, it appears the winds over hurricanes and global warming are being seriously downgraded.