Introduction
Environmental change on earth is as old as the planet itself, about 4 billion years. Homo sapiens have altered earthly environments throughout his career of Earth citizen for 4 million years. But there is nothing like the twentieth century. For the first time we have changed ecosystems with such intensity, on such scale, speed and dimension as never before. The references mentioned are just a tiny selection from the vast quantity of literature sources dedicated to the problem in consideration and include basic books and views. Most of the things people do that change environments count as economic activity.
