Climate experts warn us that the first sign of a shifting climate will be turbulent, unpredictable weather. So when Hurricane Jeanne crashed ashore in Florida in September of 2004, environmentalists couldn't help but wonder if this was it: climate change in action. It seems as though the past few years have been characterized by all sorts of weather extremes. We know that the planet has warmed 1.8 degrees Fahrenheit in the past 100 years, but is there really a link between our weather and climate change?