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Global Warming occurs as a result of increased concentration of greenhouse gases in the atmosphere. The main greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide and ozone. These gases do now allow all the radiations from the Earth to escape back info space. This is known as the Greenhouse Effect. This trapped radiation or heat helps to keep the Earth at a constant temperature. Greenhouse effect is thus very important to main the temperature of the Earth at a habitable level.
Over the past few 100 years, human have been burning trees and fissile fuels, thereby releasing millions of tones of carbon dioxide into the atmosphere. The increased level of carbon dioxide in the atmosphere has caused the temperature of the Earth to rise. This, in turn, causes more water to evaporate into the atmosphere. Water vapor is also very good at absorbing heat. This cause the Earths atmosphere to become even warmer. Scientist has called this effect Global Warming. They have warned that Global Warming could shift rainfall patterns, raise the sea level and alter the ecological balance.
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Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 C (1.4 F), with about two-thirds of the increase occurring since 1980.[2] Warming of the climate system is unequivocal, and scientists are 95-100% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation.[3][4][5] These findings are recognized by the national science academies of all major industrialized nations.[6][A]
Climate model projections were summarized in the 2007 Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC). They indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 C (2.0 to 5.2 F) for their lowest emissions scenario and 2.4 to 6.4 C (4.3 to 11.5 F) for their highest.[7] The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations.[8][9]
Future climate change and associated impacts[10] will vary from region to region around the globe.[11] The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well as a probable expansion of subtropical deserts.[12] Warming is expected to be strongest in the Arctic, with the continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include more frequent extreme weather events including heat waves, droughts and heavy rainfall; ocean acidification; and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.[13][14]
Proposed policy responses to global warming include mitigation by emissions reduction, adaptation to its effects, and possible future geoengineering. Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC),[15] whose ultimate objective is to prevent dangerous anthropogenic (i.e., human-induced) climate change.[16] Parties to the UNFCCC have adopted a range of policies designed to reduce greenhouse gas emissions[17]:10[18][19][20]:9 and to assist in adaptation to global warming.[17]:13[20]:10[21][22] Parties to the UNFCCC have agreed that deep cuts in emissions are required,[23] and that future global warming should be limited to below 2.0 C (3.6 F) relative to the pre-industrial level.[23][B] Reports published in 2011 by the United Nations Environment Programme[24] and the International Energy Agency[25] suggest that efforts as of the early 21st century to reduce emissions may be inadequate to meet the UNFCCC's 2 C target
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Global warming is defined as an increase in the average temperature of the Earths surface.
Causes of global warming:Global warming occurs as a result of the increased concentration of greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapour. These gases trap solar radiations released back by the Earth. This helps in keeping our planet warm and thus, helps in human survival. However, an increase in the amount of greenhouse gases can lead to an excessive increase in the Earths temperature, leading to global warming. Global warming is a result of industrialization, burning of fossil fuels, and deforestation.
Effects of global warming:Global warming is defined as an increase in the average temperature of the Earths surface. It has been observed that in the past three decades, the average temperature of the Earth has increased by 0.6ï½C. As a result, the natural water cycle has been disturbed resulting in changes in the pattern of rainfall. It also changes the amount of rain water. Also, it results in the melting of Polar ice caps and mountain glaciers, which has caused a rise in the sea level, leading to the inundation of coastal regions.
Control measures for preventing global warming:
(i) Reducing the use of fossil fuels
(ii) Use of bio-fuels
(iii) Improving energy efficiency
(iv) Use of renewable source of energy such as CNG etc.
(v) Reforestation.
(vii) Recycling of materials
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