Coal, cars and lorries vent more than a third of Turkey's five hundred million tonnes of annual greenhouse gas emissions—mostly carbon dioxide—and are part of the cause of climate change in Turkey. The nation's coal-fired power stations emit the most carbon dioxide, and other significant sources are road vehicles running on petrol or diesel. After coal and oil the third most polluting fuel is fossil gas; which is burnt in Turkey's gas-fired power stations, homes and workplaces. Much methane is belched by livestock; cows alone produce half of the greenhouse gas from agriculture in Turkey.