. What is global warming? Explain causes and effects of global warming.

Explanation

Causes of global warming are increasing concentration of greenhouse gases (ie.,` CO_(2)` `CH_(4)` CFCs and` N_(2)O`) in the atmosphere.
Effect of global warming: Global warming, a consequence of higher concentration of green house gases, has the potential to affect weather and climate, stratosphere and thermosphere, rise in sea level, species distribution and food production.,br> 1. Weather and climate : Global mean temperature rose by 0-60 C during the 20th century. It is going to increase further by` 1-4^(@) - 5-8^(@)`C between 1990 - 2100 AD.
2. Stratosphere and thermosphere :Warming of troposphere will cause cooling of stratosphere and thermosphere. The whole atmosphere will shrink. Cooling of stratosphere will increase the size of ozone holes and thinning of ozone shield at other places. Cooling of thermosphere will disrupt communications and the shielding effect of ionosphere.