WASHINGTON - When climate scientist Andrew Weaver considers the idea of tinkering with Earth's air, water or sunlight to fight global warming, he remembers the lessons of a favorite children's book. In the book, a cheese-loving king's castle is infested with mice. So the king brings in cats to get rid of the mice. Then the castle's overrun with cats, so he brings in dogs to get rid of them, then lions to get rid of the dogs, elephants to get rid of the lions, and finally, mice to get rid of the elephants. That scenario in "The King, the...