I am by nature optimistic, though maybe that doesn't come through in my posts here. But I think optimism without regard for potential dangers is foolhardy. "Hope for the best but prepare for the worst" is my motto.

We are currently sitting under a huge snowpack here, which has to melt sometime. If it melts too quickly, the Fraser River will overtop its dikes and a couple of hundred thousand people will be flooded out. My home is above the flood zone, but we would still be cut off for travel and likely power and natual gas. We've stockpiled food, gasoline, water, etc., all of which we can use later if the flood doesn't materialize. Probably it won't, but if it did and we weren't at least somewhat prepared, we would be up the creek without a paddle - (maybe literally!).

About global warming and other world-wide issues, I am not so optimistic. The burning of fossil fuels has undeniably (for most rational people, anyway) produced climate changes and they may well have set us on a course that is not correctable by anything realistically possible. Add to that the issue of overpopulation and all the problems associated with it - increases chances of pandemices, famine, wars, etc - plus the current political tensions, and I think we have a recipe for disaster.

The Earth, and life, will survive, and almost certainly humans too, but society as we know it - well, I wouldn't bet on it.