I think we should make every effort to try to preserve the biomes and ecosystems that are present with us now. Understand, over time, the ecosystems and biomes have evolved; change in some form or fashion is inevitable. The things we tend to do ourselves, however, such as degrading the ozone layer in the stratosphere as a result of air pollution should be held in check and limited. I saw a newsclip just the other day talking about the shrinking availability of glacial ice at the poles. One typically does not think about saving icy domains, but there are organisms, such as the polar bear, that call such domains home. The polar bear population has now dwindled to such numbers as to be on the verge of extinction, much of which can be attributed to an ever-shrinking availability of hunting ice. This ice is slowly but surely melting away as global temperatures continue to creep upward. The only way our children will be able to see polar bears in the future, if we are not careful, will be to see them in captivity, or see video footage of them.