It gets a bit technical but this is about as good as a mainstream article on climate change and global warming gets:
http://www.economist.com/opinion/displaystory.cfm?story_id=15719298
The only downside is that it focuses entirely on those errors and uncertainties that would have us currently overestimating the effects of global warming. No airtime is given to the equally valid investigation of IPCC errors that underestimate potential global warming impacts.
You can read some comments from professional climate scientists over here:
http://www.realclimate.org/index.php/archives/2010/04/the-economist-does-not-disappoint/
