You know the joke about the proverbial glass.
The optimist sees it as half full, the pessimist as half empty while the ‘realist’ grabs it and ‘enjoys’ whatever is in it.

Something of the same nature happens with the whole planet. Optimists are happily careless about what’s going on, the pessimists are terrified about the future and the ‘pragmatists’ are callously using resources as if there is no tomorrow.

To me this whole situation looks like a tree house. All three kinds of people live together in it and use as sustenance the sap of the tree limb where the house was build.
Only the branch is slowly withering away. The pessimists moan about this but don’t do anything really significant, the optimists don’t care while the pragmatists have already made plans for another house on a higher branch.

There is one small problem though. As time goes by the lower branches wither away. The tree, now old, is left with very few leaves so it can no longer grow new branches nor feed its inhabitants.
At last the hungry survivors decide to climb down and search for another tree. Yeah…but they are too high in the air to jump and the branches bellow … are no longer there!

No, I’m not desperate nor Malthusian. I’m convinced that human ingenuity can solve problems far more complicated than the ones we are facing today. Only we have to start facing them instead of turning our heads the other way.
And we’d better start solving the existing problems without adding new ones. (Iatrogenics, see Nassim Nicholas Taleb’s Antifragile…