Causes and Effects: Global Warming

 

The rise in earth’s surface temperature as a consequence of greenhouse effect is called Global Warming. The greenhouse gases such as carbon-dioxide and other pollutants absorbs more heat from the sun then it radiates back. This causes an increase in the intensity of heat in atmosphere. The thickening of earth atmosphere because of presence of increased carbon dioxide and other greenhouse gases is called greenhouse effect. 

Here's a simple definition of global warming. (And yes, it's really happening.) Over the past 50 years, the average global temperature has increased at the fastest rate in recorded history. And experts see the trend is accelerating: All but one of the 16 hottest years in NASA’s 134-year record have occurred since 2000.

Climate change deniers have argued that there has been a “pause” or a “slowdown” in rising global temperatures, but several recent studies, including a 2015 paper published in the journal Science, have disproved this claim. And scientists say that unless we curb global-warming emissions, average U.S. temperatures could increase by up to 10 degrees Fahrenheit over the next century.

Causes Of Global Warming

Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"¹ — warming that results when the atmosphere traps heat radiating from 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 vapor, which respond physically or chemically to changes in temperature are seen as "feedbacks."

Gases that contribute to the greenhouse effect include:

• Water vapor. The most abundant greenhouse gas, but importantly, it acts as a feedback to the climate. Water vapor increases as the Earth's atmosphere warms, but so does the possibility of clouds and precipitation, making these some of the most important feedback mechanisms to the greenhouse effect.

• Carbon dioxide (CO₂). A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO₂ concentration by more than a third since the Industrial Revolution began. This is the most important long-lived "forcing" of climate change.

• Methane. A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as ruminant digestion and manure management associated with domestic livestock. On a molecule-for-molecule basis, methane is a far more active greenhouse gas than carbon dioxide, but also one which is much less abundant in the atmosphere.

• Nitrous oxide. A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning.

• Chlorofluorocarbons (CFCs). Synthetic compounds entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to destruction of the ozone layer. They are also greenhouse gases.

Effects / Impact Of Global Warming

If Global warming continues the world would be in danger. The major effects and impacts of Global Warming are:

• Climate Change: Global warming is causing climate change. The world’s is becoming warmer and warmer. There is also prediction of regional climate changes along the ecosystem.
•  Sea Level Change: One major consequence of global warming arising out of greenhouse effect is the rise in sea level. Four major changes take place prior to this. They are: Thermal expansion, mountain glacier melting, Greenland ice sheet melting and Polar (Arctic and Antarctic) ice sheet melting. Thus, the coastal cities and ports may be submerged under sea-water. Many islands may vanish from the earth surface as well as from the world map. 
• Water Balance: Although changes in sea-level have received much publicity, problems of water availability are likely to be more serious and perhaps more expensive to solve. In future, warmer world will face water crisis in some parts while in other regions it will be wetter than it is not. There is uncertainty regarding regional forecasts of future precipitation as warming of globe makes it difficult to predict. Also, pattern of agricultural changes, or effects on ecosystems in general are fairly unpredictable. 
• Human Health: The human health is put at risk because of Global warming. In recent years, there have been newer reports of spread of major tropical diseases with changing climate. As the earth becomes warmer, more and more people are likely to be affected by tropical diseases.

 

Refference :

IPCC Fifth Assessment Report.  2014 . "Global Climate Change Impacts in the United States". United States Global Change Research Program : Cambridge University Press.

Naomi Oreskes. 2004.  "The Scientific Consensus on Climate Change". Science : Vol. 306 no. 5702 p. 1686 DOI: 10.1126/science.1103618

Mike Lockwood. 2009. “Solar Change and Climate: an update in the light of the current exceptional solar minimum,” Proceedings of the Royal Society A. doi 10.1098/rspa.