State in detail the causes of global warming.

The cause of global warming is the increase in concentration of greenhouse gases present in the atmosphere of the earth due to human activities. The increase in different green house is as follows:

1. The concentration of carbon dioxide has increased upto 25% due to industrial growth, combustion of fossil fuels, clearing of forests, etc.
2. The concentration of methane has doubled due to agricultural sources such as rice cultivation and animal husbandry, natural gas exploration, burning of biomass, clearing of forests and leakage in natural gas pipelines.
3. The concentration of chlorofluorocarbons has increased at a rate of 5% per year.