As another random example of why all this matters, termites.
Everyone who owns a house in most parts of Australia has at least a small concern about termites and would prefer to not find them anywhere near their property. Keeping them out is a substantial industry in many places with inspections, sprays, rectifying damage and so on.
Go get yourself the guidelines on how to keep them away and go for a walk around any suburb or town in Tasmania armed with that knowledge. You'll find just about every single house breaks the rules - timber in direct contact with the soil, firewood sitting on the ground up against the house and so on. Not an ant cap or termite barrier to be seen anywhere, nobody does annual or even pre-purchase inspections looking for them and there's no such thing as termite treated timber in Tassie either. And it doesn't matter in the slightest for one very simple reason.
No termites in Tasmania. It's too cold you see. Even the pest inspectors in other states will quote that fact first up if they know you're from Tas.
Now warm it up just a few degrees and it's not hard to see what's going to happen. Plenty of termites in Vic and plenty of things being shipped back and forth across Bass Strait. They'll be here once the climate is suitable and then half a million people all of a sudden find themselves with a problem they weren't expecting and are totally unprepared for. Odds are nobody will have a clue until something falls down and the cause is discovered. Then there'll be a panic trying to find how far they've spread and pondering what to do about all that unprotected timber in everything from fences to frames and even a few pipelines. None of it's treated against termites, that I can assure you.
So there's just one example that'll end up costing rather a lot. There will be no shortage of such problems nationally and globally for the simple reason that everything humans have built, from dams to aircraft, were designed to cope with past climatic conditions. Some will be just fine in a warmer world but others won't.