British astronomer and distinguished science journalist David Whitehouse raises the above question in a recent article in The New Statesman. "'The fact is," he says, "that the global temperature of 2007 is statistically the same as 2006 and every year since 2001."
Demonstrable, global climate change has been flat for seven years now. The closest thing I have found that turns this into a vivid image is a graph on this environmental alarmist website. Scroll slightly down from the top. Note that this graph has no bars for 2006 or 2007. So just imagine continuing the flat area at the right end of the graph for two more bars and you get the picture. Flat.
But that's not the bad news for those who are married to human-produced carbon dioxide as the cause of climate change, forsaking all others. As Whitehouse points out, carbon dioxide levels have risen relentlessly throughout the flat period. As I am sure you know, causes and effects aren't supposed to vary independently of each other. Why climate change has flattened we really don't know. But it doesn't seem like the carbon theory, plausible as it is on its own, can do the explaining by itself.
Whitehouse looks like an interesting person. You can find his charmingly low-tech web site here. He once wrote an article on UFOs called These Close Encounters of the Absurd Kind, in which he said: "I will feel more confident that aliens have landed when I see David Frost interview one." Penn and Teller should use him as a source!
Added later: Whitehouse is of course a journalist. Here is an older article with a similar point of view by Bob Carter, a scientist, a geologist who works in paleoclimatology. Note that his statement, "the last eight years [have] proved to be a period of stasis," can now be amended: the last nine years. Here is a video of a recent talk by Carter -- a very effective one!