GREEN HOUSE EFFECT

The greenhouse effect is the process of absorption and emission of infrared radiation by the gases in the atmosphere which tends to warm earth’s atmosphere and surface. It was first investigated by Svante Arrhenius in 1896 and was firstly proposed by Joseph Fourier in 1824.

Human activity since the industrial revolution has increased the amount of green house gases in the atmosphere. It was recorded that the concentration of CO₂ and methane have increased by 36% and 148% respectively since 1750. These are the highest level that are ever recorded during the last 65000 years. Three quarters of the increase in the amount of carbon dioxide is produced by fossil fuel burning while the rest is due to deforestation.

Human activities are being continued on the earth. Therefore, carbon dioxide emissions are also continuing to rise due to continue human activities like burning of fossil fuel and deforestation.Emission scenarios have been made to estimate the changes in emission level of green house gases in the future. The future level of emissions will depend on uncertain economic, sociological, technological, and natural developments.

In most scenarios, it is found that emissions continue to increase over the century while in some these emissions are reduced. These emission scenarios combined with carbon cycle have been used to predict how the concentration of greenhouse gases will change in the future.

Using the six IPCC SRES "marker" scenarios, models suggest that by the year 2100, the atmospheric concentration of CO₂ could range between 541 and 970 ppm.^[46] This is an increase of 90-250% above the concentration in the year 1750.