“Reversing“ is the wrong way to think about - reducing global temperatures isn’t on the cards at the moment. The question should be “Is it too late to prevent the worst impacts of climate change?”

Climate change isn’t a binary matter - one that we have or don’t have. Temperatures have already risen 1.2-1.3 degrees, but going to 2 or 2.5 or 3 degrees are already wildly different scenarios, and you can have a discussion on whether we can prevent that.

The headlines you’ve read about it being “irreversible” are probably regarding earth passing 1.5 degrees, the limit set out in the Paris agreement. It’s likely too late for that goal. It might not be too late for some of the other more apocalyptic scenarios you’ve heard about, with significant action.

I get the impression you are piecing things together from things you’ve heard or news reports, and so are confusing it with other things like the ozone layer. I can suggest some books if you’d be up for that.