At the other end of the spectrum - ask a European politician how great it is, when things are just fine in your relatively rich country...but an endless tide of desperate refugees from broken countries are washing up on your shores. (I had that in mind when I originally said "Percent of humanity who...".)
To try to put numbers on it - at least in America, rising sea levels, shoreline erosion, etc. have been chewing away at well-to-do coastal communities for decades now. Getting enough real-world data to say "If it would cost $X to seemingly protect a $Y property for the next Z years, then there is a W% chance that the $X will be spent" would not be all that difficult.
BUT - historical $X / $Y / Z / W% numbers could badly under-estimate the rich-country problems, if (say) public perception was that Greenland's ice sheet was doomed. (Melting that would add ~7 meters to global sea levels.) Perceived Z's would fall, and folks figuring that the deal was "after Z years at best, we'd lose both $X and $Y" might cause W% to plunge.