Wikipedia: The global warming controversy concerns the public debate over whether global warming is occurring, how much has occurred in modern times, what has caused it, what its effects will be, whether any action should be taken to curb it, and if so what that action should be. In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused primarily by human-induced emissions of greenhouse gases
Links: http://en.wikipedia.org/wiki/Portal:Global_warming
http://en.wikipedia.org/wiki/Global_warming_controversy
Climatic Research Unit documents
Climatic Research Unit email controversy
Criticism of the IPCC Fourth Assessment Report