There is a difference between natural catastrophes-those extreme events in nature, such as earthquakes that cause widespread damage- and man-made environmental Catastrophes, for which we, human beings. are responsible Man-made disasters pollute huge areas and cause extensive damage to animals, plants, and even to human beings. Examples include oil and chemical spills, accidents in nuclear power plants. over fishing in seas. and large-scale destruction of forests. The increased greenhouse effect also belongs to the category of man-made environmental catastrophes.


 HOW ARE OIL AND CHEMICAL SPILLS CAUSED? 


Chemical accidents are caused by technical problems, human negligence. and errors committed by people employed in chemical factories or in the transportation of chemicals. This happens time and again. but luckily very big accidents occur only rarely. An example would be the big chemical accident that took place in the Indian city of bhopal in 1984. oil spills happen mostly in the seas, when oil tankers accidentally overturn in the water. An overturned oil tanker pours out copious amounts of oil that flows through the water surface and submerges plants. animals, and water birds. causing many of them to die wretchedly







WHAT HAPPENS IN AN ACCIDENT IN A NUCLEAR POWER PLANT?



The reactor of nuclear power plant contains radioactive substances that are very dangerous for human beings. Such plants are monitored very carefully If a technical fault goes unnoticed there can be uncontrolled chain reactions  in the reactor. The internal pressure rises enormously within a few minutes and there is an explosion. This Is exactly what happened in 1986 in Chernobyl, an NPP in ukraine. A huge cloud of radioactive substances formed over Europe; it first settled over the Scandinavian countries, and then travelled to the Mediterranean countries via Poland and germany. The radioactive substances reached the soil through rain. People, who switched off the reactor and later cleaned up the area died from the effects of radiation.




WHAT ARE THE CONSEQUENCES OF OVER FISHING?


Over fishing means the practice of catching fish faster than they can reproduce through natural processes. over fishing inevitably leads to the depletion of other marine species including birds and mammals. As a result, the food chain  gets disturbed and animals and plants start reproducing in an uncontrolled way. The natural  equilibrium between the living communities in a marine ecosystem gets disturbed —and this is a serious environmental catastrophe.