I researched this in-depth three years ago. It's because I was on Yahoo Answers "climate change" sub-forum. There were three paid trolls who bombarded that place.
I found in my research that there are no ill effects from gloobal warming. I found these five general positives:
- Increase in polar bears
- Increase in world food production
- Increase in worldwide trees since 1985
- Decrease or stability in extreme weather (floods, tornadoes, fires, hurricanes, etc.)
- Significant decrease in climate deaths since 1930