"Excess carbon in the air is good for plants, and global warming might forestall another ice age."
Old and tired argument of narrow-minded climate change sceptics. You cannot take single facts out of the context, which is a complex adaptive system that we know only as it has operated so far. CO2 may increase photosynthesis to some degree and for some time, but I wouldn't assume linear laws. Not to mention the increase of CO2 affects not just photosynthesis; It dries out rainforests, acidifies oceans,...
Oh, stop teasing my inner climate warrior! You know he wasn't right