It's not difficult, we know what to do, and we know how to do it. We simply don't want to do it.

It's incredibly difficult in the same sense that it's "incredibly difficult" for a teenager to clean their bedroom. They could do it, and they will if forced to, but they'll drag their feet as much as possible.

That is right. Worldwide quarantine was also an even more difficult task in some ways if you really think about it but the world was much better at that (even if some countries lagged behind) because there was an immediate pain felt, not unlike a parent threatening the immediate revocation of priveleges. With climate change, there is no such immediate threat to the average high-consumption individual.