Is life on earth in danger?
Within the last 200 years man was leading earth to ecological crisis, with which we have to deal nowadays. Pushed by technological development and unrestrained desire to discover, he didn't care about the planet's condition. It's sad, that the major part of important inventions, theories and technologies were simply fruit of armaments before both World wars. We have to be happy, that the efforts excellent scientists made during the Cold war can be now adopted in medicine and protection of environment.
Nowadays the hole in the ozone layer and the greenhouse effect persuaded man, that nature it not capable to absorb all his destructive impacts. We start to limit atmosphere pollution, use unleaded gasoline and exploit natural power sources like sun, wind and water. But the most important fact is that we start to cooperate. It's important if we want heal our planet.
Maybe I'm too optimistic, but from my point of view, nowadays things are going in the right direction. I don't know whether we can say, that life on earth is not in danger. Maybe the moment we will be on the edge of extinction is still to come. We have to remember that constant destruction of our own environment will lead our (poor) civilization to extermination. I just hope that the time we realize it is to come someday.