We all are experiencing that every year summers are hotter and hotter, winters are getting less cooler and rainfall in springs or autumns is ruining all fun. Well, this is because of global warming, and humans are to be blamed for this.
What is Global Warming?
Global Warming refers to the abnormal increase in the average temperature of the Earth due to increase in concentration of greenhouse gases (e.g. carbon-di-oxide, methane, nitrous oxide etc.) due to human activities. These greenhouse gases form a blanket around the Earth’s atmosphere and help in maintaining favorable climate on Earth. But , an increase in their concentration would mean, the absorption of heat from the sun and other high energy radiations (like infrared rays, UV rays ,gamma rays) would increase leading to a significant rise in Earth’s temperature. This phenomenon is known as greenhouse effect . It has been observed that in recent decades that over a period of 50 years, the average temperature of earth has risen at the rate of 0.74 +- 0.18 °C. The rate of increase is 2.5°C per decade (nearly 3 times since 1970) and since 2000, its much more. The temperature of Earth is expected to reach upto 64°C by the year 2100.
Major Greenhouse Gases:
- Oxides of carbon (carbon-di- oxide , carbon mono-oxide):
It occurs naturally due to respiration in living organisms and natural degradation of plants and animals. It is also produced due to human activities like combustion of fossil fuels and smoke from automobile exhausts. It is responsible for 55% of global warming.
- CFCs (Chlorofluorocarbons):
It is used as coolants in A/Cs, refrigerators and cleaning solvents. It escapes as aerosols into the atmosphere. It is responsible for ozone layer depletion. It is responsible for 10-24% of global warming.
- Oxides of sulphur( sulphur-di- oxide , sulphur -tri-oxide):
It occurs naturally due to volcanic eruptions and decay of plants and animals. It is also produced due to human activities like combustion of fossil fuels and smoke from smelting plants. It is responsible acid rain.
- Oxides of nitrogen ( nitric oxide , nitrous oxide):
It is released in atmosphere due to excessive use of fertilizers and pesticides. It occurs naturally due to lightning discharge and anaerobic respiration of microbes. It is also responsible acid rain. It is responsible for 6% of global warming.
Consequences of global warming:
Global Warming is causing great changes in our ecosystem. Increase in global temperature hinders other natural phenomena.
Some consequences of global warming :
- Change in blooming seasons of plants
- Dislocation and extinction of flora and fauna– Reports show that due to abnormal climatic changes 30% of plants and animals are expected to go extinct by 2050. It is predicted that in future animals and humans will shift to higher latitudes from equatorial regions in search of a more favorable climate.
- Increase in death due to heat strokes in equatorial regions
- Rise in sea level- The increase in Earth’s average temperature has caused melting of glaciers in the Arctic and Antarctic regions. This has lead to increase in sea level which has caused several coastal floods . Greenland has experienced 32 glacial earthquakes in a year, causing casualties and severe damage to local infrastructure. The sea level is increasing at the rate of 3.1 mm per year.
