Tag: global environmental change

Carbon dioxide is a naturally occurring gas. It shows greenhouse effect by absorbing the the long-wavelength infra-red radiations coming from the earth's surface and preventing from leaving the atmosphere. This effect is responsible for maintaining the ambient temperature on the earth. However, due to increase in combustion of fossil fuels like petroleum and coal and excessive deforestation, the amount of carbon dioxide has increased over the past years and this has adversely affected the global temperature by raiding it. This is called global warming and is responsible for climate change. 

• The Chernobyl disaster was a catastrophic nuclear accident that occurred on 26 April 1986, in the No. 4 nuclear reactor at the Chernobyl Nuclear Power Plant, near the city of Pripyat, in the north of the Ukrainian SSR. Which resulted in accidental leakage of radioactive wastes into the surrounding atmosphere which caused a large number of loss of human life and many genetic disorders due to radioactive mutations.
• El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO). It results in climate change.
  
• Snow blindness is a painful, temporary loss of vision due to overexposure to the sun's UV -B rays. Its symptoms include inflammation of the cornea.
  
• So, the correct answer is 'a,b,d'.

El Niño Southern Oscillation refers to the cycle of warm and cold temperatures, as measured by sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. These changes in tropical rainfall affect weather patterns throughout the world, particularly for the national agriculture, fishing, forestry, and energy sectors.

The greenhouse effect is a naturally occurring phenomenon responsible for heating surface and atmosphere of earth. It is caused due to the presence of greenhouse gases like CO$ _2$, CH$ _4$ and CFCs etc. An excess amount of these gases cause global warming. The greenhouse gases are responsible for the greenhouse effect.

The burning of fossil fuels leads to increase in the concentration of carbon dioxide levels in the atmosphere. Svante Arrhenius (1859-1927) was a Swedish scientist who was the first to claim in 1896 that fossil fuel combustion may eventually result in enhanced global warming. He proposed a relation between atmospheric carbon dioxide concentrations and temperature. He found that the average surface temperature of the earth is about $15^0$C because of the infrared absorption capacity of water vapour and carbon dioxide. This is called as the natural greenhouse effect.