Rome is on the Tiber, which flows directly into the Tyrrhenian Sea (via Ostia, which was Rome's "Oakland" and had its own sizeable population in antiquity). London, Thames. Paris, Seine.

(Closer to MENA and the Levant, and you'll find that antiquity cities almost entirely exist on the Tigris, Euphrates, Nile, etc. You can find inland Silk Road ksour in countries like Morocco, but these too exist along seasonal rivers, and have correspondingly lower and nomadic populations.)

I don't particularly disagree about climate change, and I think a lot of the coastal Southern US is in for a rough awakening in the next 15 to 30 years. But things haven't been so peachy inland either (the Midwest has had both more numerous and more severe floods, tornadoes, etc.). NYC's weather is also certainly going to become more extreme, and the city's response so far has been unimpressive.