The Hype and Beyond
Climate change has been the buzzword around the globe during the recent years. From governments to civil society organizations to academia, everyone is talking about it, and is wary of the adverse impacts this phenomenon is going to have on terrestrial life. There is hardly any difference of opinion that climate change is occurring – difference of opinion, however, exists over where it will lead. Majority believes that if left unchecked, climate change will ultimately make life on earth a rarity, if not impossibility. A small section of experts holds that it will be set off by nature in times to come, like multiple events of warmer temperatures followed by ice age in the past.
What is Climate Change exactly?
Definitions vary. In general, it is a change of climate, which is directly or indirectly related to human activity that alters the composition of the global atmosphere, and which is in addition to natural climate variability over comparable periods of time.
A 2001 statement from the Intergovernmental Panel on Climate Change (IPCC) read: “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and oceans have warmed, the amounts of snow and ice have diminished, and sea level has risen. Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history.” The most recent scientific assessment by the IPCC suggests that the global average surface temperature on Earth will increase by 1°C to 3.5°C (about 2°F to 6°F) by the year 2100, with an associated rise in sea level of 15 to 95 cm (6 to 37 inches).
Causes of climate change are multiple but all of them are brought about by human activities. Main cause of the current global warming trend is human expansion of the “greenhouse effect” – warming which results when the atmosphere traps heat radiating from the Earth toward space. Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as “forcing” climate change. Gases, such as water vapour, which respond physically or chemically to changes in temperature, are seen as “feedbacks.” Gases that contribute to the greenhouse effect include water vapour, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons (CFCs).
Human activities are changing the natural greenhouse effect. Over the years, burning of fossil fuels like coal and oil, emissions from industries and vehicles, decomposition of wastes in landfills, agriculture, especially rice cultivation, use of commercial and organic fertilizer and burning of biomass have increased the concentration of atmospheric carbon dioxide (increased from 280 parts per million to 400 parts per million in the last 150 years), methane, nitrous oxide and chlorofluorocarbons. To a lesser extent, clearing of land for agriculture, industry and other human activities, as well as deforestation have increased concentrations of greenhouse gases.
Some quarters argue that changes in the sun’s energy output have caused the climate to change. Evidence, however, shows that current global warming cannot be explained by changes in energy from the sun because NASA’s data establishes that since 1750, the average amount of energy coming from the sun has either remained constant or has increased slightly. Moreover, if the warming were caused by a more active sun, scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead, they have observed a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. That’s because greenhouse gases are trapping heat in the lower atmosphere.
Read More: Climate Change
Sorry you have no rights to view this Article/Post!
Please Login or Register to view the complete Article
To get full access EMAIL your username, Subscription Plan and email address at email@example.com for details
SUBSCRIPTION PLANS Rs. 3300 for 1 year.
This post has been seen 86 times.