Climate Change: A threat to mankind

Climate change presents a great risk to humans. Impact of the change has already started to show in Sunderbans where agriculture productivity has declined putting a lot of people at the risk of starvation

CJ: Sonali

Sun, Apr 12, 2009 18:09:25 IST

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Environment News :

BEGINNING WITH the Industrial revolution in the 19th century and accelerating since then, there has been an increase in the emissions of various green house gases (CO2,CH4,N2O,SF6,HFC & PFC) in the atmosphere causing an abnormal increase in the temperature of earth.

Due to the presence of these gases, the heat that earth receives from the sun is not radiated back to the desired extent and the heat gets entrapped in this process, thus raising the earth’s average temperature.

As the ability of the atmosphere to capture and recycle energy emitted by the earth’s surface is essential for a stable climate, this heightened temperature may introduce de-stabilising influence and potentially affect global weather patterns and eventually long term climate change.

The human consumption of fossil fuels has elevated the CO2 levels from a concentration of approximately 280 ppm in pre industrial times to 387 ppm today. The concentration is increasing by 2-3 ppm/year. If the current rate of emissions continues, then these increasing emissions are projected to be of the tune of 538-987 ppm by the end of the 21st century. Cement industry is the major contributor of CO2 constituting five per cent of the total Carbon dioxide produced.

Aerosols, small particles suspended in air with a lifetime of at least minutes, are either emitted as primary aerosols (dust or particle emissions of diesel cars) or formed by the conversion of sulphur dioxide, nitrogen oxides, ammonia and organic compounds present in atmosphere. By chemical reactions these gases form sulphates, nitrates and ammonium compounds, and non-volatile organics (secondary aerosol). These particulate matters also play an important role in Climate change.

Along with rising Methane levels it is suggested that due to all these factors there will be a rise of 1.4-5.6 degree celsius in the earth’s average temperature between 1990-2100. The increase of methane level is mainly due to livestock and paddy fields.

Prior to widespread use of fossil fuels, humanity’s biggest threat to climate change was from land use, agriculture, irrigation and deforestation. With the changin pattern of land use, the pattern on absorption and redirection of sunlight changes causing local climate change.

There is evidence to suggest that the climate of Mediterranean and Greece was completely changed to hot and dry because of widespread deforestation between 700 BC to 1 AD.
The changes may lead to a rise in sea levels, a change in vegetation zones, an increase in disease levels and a change in ecosystems. The possible effect of climate change may be sea level rise in Bangladesh and Pacific, risk of flooding of Maldives, storm surges risk to Florida, melting of the glaciers of the European alps, which will have an economic impact to ski resorts, soil erosion and crop failure in sub Saharan region. Apart from these, North Atlantic Ocean current may change, which in turn will affect climate of Great Britain. The list is long, these are a few of them.

As per WWF reports, 300 million people across nations will find themselves at greater risk of malaria and other water borne diseases by 2020. It further states that ice sheets and sea level rise will put around 100 million people at risk of coastal flooding. Impact of climate change has already started to show in Sunderbans where agriculture productivity has declined putting a lot of people at risk of starvation.

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