There are five gases of human origin that contribute most – together up to 95% of the total – to the increase in global warming. Here you will discover the source of their emission, the time they spend in the atmosphere and what percentage they contribute to the greenhouse effect. Carbon dioxide is responsible for 53% of the level of global warming. It is the result of processes such as fuel use, deforestation and production of cement and other materials. Its permanence in the atmosphere varies, but it’s very high at all times: 80% lasts for 200 years and the other 20% can take up to 30,000 years to disappear. Methane is the next of the greenhouse gases which has the biggest effect on global warming (15%). This is generated by activities such as livestock production, agriculture, sewage treatment, natural gas and oil distribution., coal mining, fuel use and is also given off from waste tips. It lasts an average of 12 years in the atmosphere.