The price of food and reasonable medical care have fallen so much that the world population swells to levels scarcely imaginable 200 years ago. Whenever you get a bunch of people together in a tropical climate they inevitably seem to say to each other “Let’s go out and cut down all of the trees in the jungle so that we can grow crops or graze cattle.”
The last tropical rainforest left will very likely be the one right here in central Panama for it supplies one thing that is undeniably critical for the operation of the Canal: rain. The heart of the 80 km-long Canal is a big lake, 26 meters above sea level. Every transit of a ship through the Canal requires that 52 million gallons of fresh water drain out of this lake into the Caribbean and Pacific. The water is replenished from surrounding rainforest. One thing that people in this part of the world have learned is that when you cut down all the trees it changes the local climate, generally cutting the amount of rain that falls.
Panama is one of the few places in the world where you don’t need a hippie environmentalist to talk up the value of the rainforest. Here everyone knows what the rainforest is worth… $600 million per year in tolls.