Some greenhouse gases originate from natural sources. Typical, evaporation adds water vapor into the atmosphere. Animals release CO2 when they breathe, or respire while methane is released from some low-oxygen environs naturally, such as swamps. In the other hand, nitrous oxide is formed by certain processes in water and soil. Volcanoes - both under the ocean and on land - release greenhouse gases, hence periods of high volcanic activity level tend to be warmer.
From the time of the Industrial Revolution in the late 1700s to early 1800s, mankind have been releasing large amounts of greenhouse gases to the atmosphere (King, 2010). That amount has rose steeply in the previous century. Greenhouse gas emissions augmented by 70% between 1970 and 2004. CO2 emission, the most significant greenhouse gas, rose by around 80% during that time. The quantity of atmospheric CO2 today far exceeds the normal range seen over the previous 650,000 years (Steinberg, 1998).
Big amount of the CO2 that human being put into the atmosphere originates from burning fossil fuels. Vehicles, trucks, trains, machinery, and planes all combust fossil fuels. Most electric power plants do, also. Another way humans discharge CO2 into the atmosphere involves by cutting down trees, because trees hold large amounts of carbon through photosynthesis. People increase methane to the atmosphere by livestock farming, landfills, and relic fuel production such as natural gas processing and coal mining. Nitrous oxide comes from fossil fuel burning and agriculture. Fluorinated gases include hydro-chlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs). These gases are used in refrigeration and aerosol cans (Steinberg, 1998).
All of these human practices add greenhouse gases to the Earth’s atmosphere. As the level of greenhouse gases rises, so does the Earth’s temperature. The rise in Earth’s