Forbes: There are few more startling embodiments of climate change than the current health of China’s largest freshwater lake, Poyang Lake, in the southeastern province of Jiangxi. As is now customary in discussions involving global warming, the following statistics are liable to alarm. The surface area of Poyang Lake has shrunk to 50 square kilometers from its peak of more than 3,000 during the summer–it is 1.67% of its size six months ago. Some perspective is needed. A spectacular …