But the impact of these anthropogenic emissions became significant only with the increasing pace of industrialization. Rising CO2 emissions, which cause an accelerated anthropogenic greenhouse gas effect, have been driven primarily by the combustion of fossil fuels and by the production of cement. Methane emissions (from rice fields, landfills, cattle, and natural gas production) and nitrous oxide (originating mostly from the rising application of nitrogenous fertilizers) are the other notable anthropogenic sources of greenhouse gases.
