Chemicals from air-conditioning units and refrigerators in daily use throughout Asia could cause catastrophic climate change unless we change our ways soon, scientists say. Called hy/dro/chlo/ro/fluo/ro/carbons (HCFCs), the chemicals were widely adopted about 20 years ago after it was discovered that the chemicals being used until then – chlorofluorocarbons (CFCs) – had been depleting the ozone layer.