Global Warming is the increase in average temperature of earth surface. Over the past century, Earth has warmed by around 0.9 degree C.
Yes, its a very serious matter, that we should worry about. If global warming keep on increasing like this it can one day change the whole condition on earth in a negative way, many species of animals and plants will disappear, including humans. Major effect of Global warming are climate changes (sudden increase and decrease in temperature without any order like now it is going) Frequent heat waves, rising sea level, melting of glaciers, natural disasters like floods, and droughts, failing crops. These will cause the lack of food in the whole world and people will die from appetite, various diseases as glaciers had melted, as according to many scientist in glaciers there are 100 of bacteria and viruses are trapped which can cause a great damage to life.
We are facing Global warming on large scale because, we human are exploiting our earth for our own profit and requirement ignoring the fact that in future we have to face great consequences. we know everything but our greed for more made us do wrong every time regardless that what we are doing is wrong. Human activities like air pollution, industrialization and deforestation, volcanic eruptions and solar variations are major causes of global warming. and the most important depletion of ozone layer. It is the only layer that protect earth from it direct heat rays i.e. Ultra violent rays which is the major cause of global warming. The reason of depletion of it is chloro fluorocarbon, carbon monoxide, etc hot gases that comes 70 to 80 % from Air conditioners and refrigerators. These gases are hot so they goes up in the atmosphere easily and react with ozone and break it into Oxygen and O elements (ozone is made of 3 particles of O).