In this blog, we will discuss main causes of Global Warming namely, emission of Greenhouse gases and the chemical concepts involved .
Concept 1 : Emission of Green house gases
Green House gases are gases in the atmosphere that trap radiation as they vibrate, (also known as GHG for short) ,and are largely responsible for the greenhouse effect.You can refer to this link for an example of the vibration of CO2. (https://www.youtube.com/watch?v=W5gimZlFY6I)The greenhouse effect is one of the leading causes of global warming. The most significant greenhouse gases are water vapor (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), according to the Environmental Protection Agency (EPA).
Type of green house gases
Carbon dioxide (CO2)
- Carbon dioxide enters the atmosphere through burning fossil fuels (coal, natural gas and oil), solid waste, trees and wood products, and also as a result of certain chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere when it is absorbed by plants as part of the biological carbon cycle.
- Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.
Nitrous oxide (N2O)
- Nitrous oxide is emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.
- Hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes. Fluorinated gases are sometimes used as substitutes for stratospheric ozone-depleting substances (e.g., chlorofluorocarbons, hydrochlorofluorocarbons, and halons). These gases are typically emitted in smaller quantities, but because they are potent greenhouse gases, they are sometimes referred to as High Global Warming Potential gases (“High GWP gases”).
So how so Green House gases trap radiation?
The Mechanism is fairly Simple.
The Diagram above can be used to explain the process.The natural Green house affect is a healthy and natural process which occurs to keep the Earth at warm enough temperature in order to sustain life.This occurs when the Green house gases in the atmosphere trap some of the energy from the sun, incident on the surface , and then radiates most of the heat back into space.
However, the enhanced green house effect is what we should be worried about. With higher concentrations of gases like Carbon dioxide, methane and nitrous oxide, more heat is trapped by these molecules, thus radiating lesser heat back into space than before. This causes the average temperatures on the surface of the earth to rise every year.