Greenhouse gas emissions by Russia are mostly from fossil gas, oil and coal. Russia emits 2 or 3 billion tonnes CO2eq of greenhouse gases each year; about 4% of world emissions. Annual carbon dioxide emissions alone are about 12 tons per person, more than double the world average. Cutting greenhouse gas emissions, and therefore air pollution in Russia, would have health benefits greater than the cost. The country is the world's biggest methane emitter, and 4 billion dollars worth of methane was estimated to leak in 2019/20.