While somewhat sympathetic, I remember reading a bit about these a year or so ago.
If the Brits hadn't "stolen" them, they would be almost rubble as proven by the very poor condition of remaining Parthenon Marbles or similar left in the care of Greece.
What he said. There would be nothing left. The Ottoman Turks were using the Parthenon for target practice and the Greeks at that time were not at all concerned. Greece didn’t care about these treasures until the Brits valued them and saved them, and then it took the Greeks several decades to get around to trying to reclaim them. More a case of “savers-keepers” rather than “finders-keepers.” Left to the Greeks, these treasures would be lost to the world.
That's an old and obviously careless argument coming from the Brit side. When there last summer I did not notice the Parthenon to be any worse for wear and in any case the new museum will be more than adequate to house them.
In fact the damage done by the chemical scrubbers in the British Museum far outweighs any potential damage done by the “pollution” in Athenian skies.