Hmmm, interesting statement. What would you define as mankind's "natural habitat"? The African plains? Anywhere that "cavemen" lived? Anywhere on the planet mankind can survive using stone tools and animal skins?

It seems to me our natural habitats are anywhere but underwater, mountain tops and maybe Antartica (though I think Inuits could probably make a go there...).

I always laugh when people talk about mankind being the only ones who poison their own environment. It shows the person has no scientific background. Yeastkind will multiply over an over until they kill themselves and every other living thing off with their own pee. Then we drink the resulting chemical wasteland after a hard day's work (beer/wine/hard liquor).

Another example? The original blue-green algae. Before they appeared Earth's atmosphere had very little oxygen. Over the course of time these algae produced enough oxygen to trigger a massive self-extinction.

True, mankind has the ability to reason and therefore should be able to avoid this same fate. You know what? Very smart people are working on the problem. Some are looking at ways to reduce waste. Some are looking at ways to escape the planet. I have complete faith in mankind's ability to come up with a valid technological solution to the problems we face. Heck, the fact that the oil industry saved the whales from extinction is proof of that.

What, you didn't know that? Remember reading "Moby Dick" in high school? People used to hunt whales for the oil they contained. This oil was burned in lamps and lubricated machinery. Eventually the number of whales was reduced to a handful and everyone panicked that "Peak Whale Oil" had occurred and now we were all headed back to the dark ages. Luckily a guy figured out the black goo seeping out of the ground in Pennsylvainia and Ohio could be refined into lamp oil and lubricants. Overnight whale oil was replaced by "rock oil" and the whales were left to repopulate the oceans.

Mankind is smart. A lot of times it may not seem so, but it is.

-Blast

p.s. Besides, at the risk of sounding egocentric, what use is a world if there's no sentient life to admire it? Rocks/plants/cats don't care or notice that they exist.