Greenhouse gases typically come from almost every human activity. [18] While electricity (including heating and air conditioning) is the largest contributor, land use change, transportation and agriculture are other major categories. Energy consumption is proven to be the main contribution to greenhouse gases increasing with 61 percent. [18] Most CO2 is the result of burning fossil fuels while most CH4 and N20 comes from agriculture and wastes. Cattle contribute largely to the methane in our atmosphere because of the large amounts of food they eat (some of the food gets converted to methane by the stomachs). The following figure shows how our energy consumption methods are directly related to C02 emissions. [19]
It is easy to see that most carbon dioxide emissions are from the uses of petroleum and coal. Residential and commercial sectors use most of their energy to make electricity [19] and the figure below shows their percentages. Coal is clearly the dominant energy source related to electricity generation.
