Plants are engines powered by the Sun. The very purpose of those leaves is to tap the flow of solar energy. When the giant celestial nuclear reactor is taken into account, the entropy of the entire system is increasing.
Plants are engines powered by the Sun, made almost entirely out of water and air.
Just had to throw that in, otherwise I would have modded up your answer.
UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things. -- Doug Gwyn