USA Today featured today an article on a growing--but not completely solid--consensus that human doings have more to do with current climate change than changes in solar radiation and other fluctuations outside of our control.
Climate scientist Roger Pielke Sr. of the University of Colorado at Boulder has suggested that development and deforestation, rather than the burning of fossil fuels, are the main drivers behind global warming. He says on his climate-science website that the IPCC should recognize the importance of these other factors.
In contrast, Australian scientist Tim Flannery has complained in his 2005 book The Weather Makers: How Man is Changing the Climate and What it Means for Life on Earth that IPCC estimates downplay the impact of warming.
On a related note, I am glad to see that the Democrats in Congress have started hearings on political interference with government scientists working on climate issues. It is bad enough that the issue becomes politicized. ("Global warming is a hoax!" "Global warming is the personal fault of George W. Bush!")
Pielke's group has a climate-change blog, which I am adding to the blogroll for occasional study.