GREENHOUSE GASES AND THEIR EFFECT ON EARTHS CLIMATE.

 Greenhouse gases like Carbon Dioxide absorb the Sun's heat that radiates from the Earth’s surface and prevent it from escaping it into space. This is to an extent good for mankind because without the presence of Greenhouse gases in the atmosphere, the temperature on the Earth would have been below the freezing point making it impossible for humans and most other species to evolve and survive.

Many greenhouse gases occur naturally in the atmosphere, but human activity too contributes to their accumulation.

Naturally occurring Greenhouse

 gases are Carbon Dioxide, Methane (CH4), and Nitrous Oxide (N2O). Humans also contribute to the accumulation of these gases as well. .

Fluorinated gases (F-Gases) are manmade gases used in the industry and they have a high global warming potential that is thousands of times more than Carbon Dioxide.  They include Hydrofluorocarbons (HFC), Perfluorocarbons (PFC), Sulphur Hexafluoride (SF6) and Nitrogenfluoride (NF3). They are used as refrigerants, solvents and in manufacturing.

As you can see from the above chart, since the pre-industrial period, the average temperature of the earth has gone up by 1 degree Celsius between the years 1880 and 2020. Primarily fossil fuel burning is the main cause of this increase.

Direct measurements of Carbon Dioxide since the year 1958 indicate that its concentration in the atmosphere has increased from 317 PPM (parts per million) in 1958 to 424 PPM in 2024 Feb. That is a 34% increase in 66 years or about 0.5% average increase every year. This increase seems to have accelerated now because the year 2023 saw an increase of 1.1% compared to 2022.

The amount of Carbon dioxide emitted by burning fossil fuels in the year 2021 is an astounding 36 billion or 3600 crore tons. However, the good news is this quantity is lower by 22% compared to the year 2008.

China, the USA and India together consume about 54% of the World’s total consumption of fossil fuels.  In the year 2022 over 80% of the primary energy consumption and 60% of its electricity came from fossil fuels.

Global warming contributes to climate change which adversely affects the Earths life. The year 2023 had been the warmest year on record with the temperature being 1.18 degree above the 20^th century average. The 10 years between the years 2014-2023 are also the warmest on record. Temperature recording began in the year 1895, so we have the temperature records for the past 129 years now.    

The average temperature of the Earth is 15 degrees Celsius. However, one has to remember that the coldest place on the earth and the hottest place on the earth on an average have a differential of 55 degrees centigrade, so the average temperature does not tell you much.

The coldest temperature ever recorded on the earth was -89.2 degrees C recorded  in 1983 at Vostok station in Antarctica. The coldest inhabited town is Oymyakon  a small village in Siberia where temperature dips to -71 degrees. The hottest temperature recognized in the world was recorded at Death Valley California in 1913 which was 56.7 degrees.  

During the last 43 years temperature of the Earth has risen by 0.20 degrees per decade. A rise of a few degrees may not look like much but during the last ice age North America was covered with more than 3000 feet of ice when the average temperature was cooler by only 5 to 9 degrees compared to today.            

As the global temperature becomes warmer, there would be extreme changes in weather patterns. One of the most dramatic effects of global warming is the reduction in Arctic sea ice and also the reduction of glacial ice.

As the ice melts, the sea levels rise. The pace of sea level rise doubled from 2.1 mm per year between the years 1993 to 2002 to 4.4 mm between 2013 and 2021.. Melting Polar ice in the Arctic and Antarctic regions and also melting ice sheets and glaciers across the world. Global sea level has risen by about 8 inches since the year 1870. The increase is expected to accelerate in the coming years. If the Greenhouse emissions remain unchecked these levels is likely to rise 3 feet by the year 2100.

Carbon Dioxide also has another effect on the climate. The oceans absorb some of the Carbon Dioxide which increases the acidity of sea water. When CO2 is dissolved in sea water it becomes carbonic acid. Since the Industrial Revolution began in the early 1700’s the acidity of the ocean has gone up by 25%.

So, the net effect of Greenhouse gases is, that they increase global warming thereby changing climatic patterns, resulting in a rise in the sea level by melting glaciers and carry out acidification of the sea waters. Despite these warning bells, the problem has not got out of hand as organizations like the Greenpeace suggest. They over-exaggerate climatic changes and the biggest silver lining against such doomsday arguments is that carbon emissions have actually decreased by about 22% between the years 2008 and 2021. Actually realizing the seriousness of the problem is half the problem solved. Countries are consciously taking care of their carbon emissions now and the emissions are bound to come down with time alleviating the problem.  

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