The only thing that really frightens me is climate change. The other stuff (Ukraine, inflation, recession, energy prices, etc) will pass, but climate change is going to get worse. This summer scared the crap out of me. Forty degrees just isn't normal. A climate expert on Newsnight said that without climate change, the UK would never hit 40 degrees. It just wouldn't happen.
I've heard several idiots (all men, all at barbeques) say "well, if this is climate change, bring it on!" But climate change doesn't just mean nice summers. It's everything that goes with - flooding, drought, crop failure. Then there is mass migration. Africa's population is going to double by 2050. When climate change gets worse, that booming population will migrate north to Europe, totally de-stabilizing the continent. Climate change sets off cycles of problems: infrastructure is shattered and crops fail, people then get displaced, which in turn triggers wars or revolutions, which then escalate, and so on. Right now we can cope. But if it gets as bad as some fear, we won't, not with the world's population heading to nine or ten billion.
It's overpopulation combined with climate change that scare me. Those two things will combine to crash our civilization. In 1800 there were roughly 1 billion humans on earth. By 1900, it was 1.5. By 1960 it had doubled to 3 billion. By 2000 it had doubled again to 6 billion. We're now close to 8 billion. I feel like the population will keep increasing, and climate change will keep getting worse, until we reach a kind of endpoint and our civilization collapses.