Rainforests act as the world's thermostat by regulating temperatures and weather patterns. For our endurance they function as the lungs of the planet transforming carbon monoxide to oxygen. In addition they are critical in maintaining the Earth's limited supply of drinking and fresh water.
The value of the rainforest has been underestimated in the past. A vast amount of rainforests had been destroyed because of commercial and industrial purposes that were approved by short-sighted governments. Because of deforestation a significant amount of the world's species of plants, animals and microorganisms were extinguished or are presently endangered.
Before humans created the problems of overpopulation, unnecessary fanatical consumerism, and excessive pollution, the normal rate of extinction was one species every four years. Today species are going extinct at the absurd rate of 30,000 per year (or a higher number - depends on the source). That’s 82 species every day, four species every hour.
As the rainforest species disappear, so do many possible cures for life-threatening diseases. At least 25 percent of all modern drugs originated in rainforests. Scientists have identified more than 2,000 tropical plants as having anticancer properties, for example.