The gradual warming up the Earth is called warming. (alogbl) Acid destroys trees and kills fish in lakes. (ianr) Many factories dump dangerous straight into the sea. (michecals) Burning things releases dioxide into the atmosphare. (boncar) Huge areas of tropical rain are disappearing every year. (orestf) The exhaust fumes from cars and lorries cause serious in many cities around the world. (llutionpo)