When I asked my brother [retired NASA scientist and still a participant in NASA's Houston climate study group] about global warming, he email back an overview. Here are some quotes:
" The truth lies between those who say there is no global warming caused by humans and those who say the Earth and mankind face rapid and certain catastrophe. My view is that we cannot ignore future warming, but response should be measured, phased, and carefully thought out."
" The "doom predictors" use computer models of future warming. These model predictions are all over the map, but in past have predicted more warming than occurred. Models range from about 2 to about 8 deg-C total warming for each CO2 doubling. The truth is likely between 2 and 3. But politicians and Greens adopt numbers of 5 to 8, which are unlikely. "
" The "doomsdayers" have claimed that warming causes more extreme weather. I attach a science summary I wrote on that over two years ago. It is mostly data graphs from the published literature. Bottom line -- some extremes caused by warming, most not. "