Global warming is described as the apparent rise in the average normal temperature of the planets atmosphere and its seas in the immediate past decades. This takes into consideration its progression in the years to come.
In the 1900s, the average temperature near the lowermost layer of the earths atmosphere increased by A±0.2 A°Celsius or 0.4 A°Fahrenheit. Most scientists studying climate change opine that this 50 years of observed global warming can be blamed on human activities.The main cause of waming is the marked rise in the concentration of greenhouse gases or GHGs like carbon dioxide (CO2), which aggravates the greenhouse effect by warming the surface of the earth and the lower portion of the atmosphere. Destructive activities like the burning of fossil fuels, land denudation and other agricultural practices contribute to the proliferation of these greenhouse gases.
Projections made by the Intergovernmental Panel on Climate Change or IPCC reveal that global temperatures should increase from 2.0 – 5.8 AÂ°C or from 2.5 -10.5 AÂ°F between 1990 and 2100. This wide range seems uncertain, the exact value cannot be pinpointed as it is highly improbable to predict the level of future emissions of greenhouse gases
(no one knows how much fossil fuel would be left then). Moreover, climate sensitivity cannot also be predicted.
Higher global temperatures bring about drastic changes which include a rise in sea level, as well as the volume and the erratic pattern of rainfall. These changes can increase the danger of extreme weather conditions, eg. raging floods, extended droughts, killer heat waves, killer hurricanes, and super tornados. Still other results would be unpredictable yields, melting of glaciers, drying up of streams especially during summer, extinction of certain species and more violent strains of diseases. While it is true that global warming undoubtedly affects the frequency and degree of the aforementioned incidences; it is, on the other hand, also difficult to blame these undesirable turn of events to global warming. Most projections cover the period till 2100; warming and the consequent rise in sea level is seen to go on beyond then as carbon dioxide has a relatively long atmospheric lifetime.
Climate change, which is the more general description of global warming, could also refer to global cooling as what transpired during the ice ages. Global warming happens naturally, but is more associated with human neglect and abuse. However, most researches and write ups referring to global warming are done in the context of human influence.
For the past 400,000 years, accumulation of carbon dioxide from start of the Industrial Revolution, has altered the Earth’s pathway around the Sun, or Milankovith cycles as it is known. Major changes in the climate system can either occur naturally or be caused by external factors, outside of human or non-human influence. This includes developments in solar movements and alignment, emissions from volcanic eruptions, deviation in the earth’s pathway or orbital forcing and the formation of greenhouse gases. Scientists who study climate changes agree that the earth’s temperature has indeed risen alarmingly.