One of Chennai's biggest reservoirs, Chembarambakkam Lake, is now a cracked, windswept mud flat. There are swarms of insects as big as hummingbirds, stray goats nibbling at dust-coated shrubs and what look like a few water buffalo – but no water. A massive pipe that's supposed to carry water into the city is empty.

Rome is known as the Eternal City. Over many centuries, it has been sacked by marauders and repeatedly resurrected from decline. But this summer, Roman residents are being tested by a massive trash crisis that has prompted doctors to warn of the possible spread of diseases as birds, vermin and wild animals scavenge amid the rotting refuse.

Already, flocks of cawing seagulls have replaced traffic roar as the soundtrack of Roman life.