My guess is that climate change, providing it doesnt become runaway, will have as many plusses as negatives.
Given that the evidence points otherwise, I think your guessing might be more than slightly optimistic, Howard.
The downsides are lower agricultural output due to disrupted water supplies and disrupted weather patterns, greater death rates in children and the elderly due to much hotter summers, collapse of fish stocks due to oceanic warming and acidification, loss of human habitat due to sea level rise, loss of fresh water supplies on which 1/6 of the world's population depends due to glacial melt, and massive acceleration of the greenhouse effect when the tundra melts and the clathrates release all the methane.
On the other hand, the winters won't be so cold, so they won't need to salt the roads so much. So it's not all bad...
