Ozone-depleting substances such as CFCs, HCFCs and halon were once used in refrigerators, aerosols and industrial processes, and they damaged the layer of the stratosphere that shields Earth from harmful ultraviolet radiation. In 1987 countries signed the Montreal Protocol to phase them out. Since then, emissions of these substances have fallen by more than 99 percent, according to Our World in Data's analysis. The treaty is widely regarded as one of the most successful international environmental agreements. Replacement chemicals and phase-out schedules were agreed over the following decades. The chart shows the steep drop in emissions after the protocol took effect.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.