climate science is in. really?, page-5

You might as well give the credentials of Christie, Lindzen and Singer as well. None dispute the greenhouse effect or global warming. They just say that 'we don't know just how hot it's going to get'. Which is true. It all depends on what we do about it.

We might already be too late to stop the warming at 2 degrees Celsius, but if we act soon enough, we might be able to keep it at 3C, although to survive at this level will take a lot of adaptation. (Witness the weather disasters just this decade and the temp hasn't gone up 1C yet.)

Predictions are tricky in part because it requires different assumptions about human behaviour (scenarios). The following is one attempt:
http://www.scientificamerican.com/article.cfm?id=how-much-global-warming-are-we-willing-to-take