It is the process in which heat from the sun is trapped in the earth's atmosphere as a result of pollution. Scientists think that the earth's surface has risen by I degree over the last 100 years. 
I degree over many years may not seem like much but global warming can be devastating to our planet.

Carbon dioxide pollution spewing from our cars and power plants is building up in the atmosphere and causing global warming.  According to scientists, global warming will damage coasts and crops, encourage the spread of infectious diseases and lead to the extinction of many plant and animal species.

The Environmental Protection Agency (E. P.A ) outlines the many effects of global warming including climate change, expansion of deserts and rising sea level.

The effect of global warming on humans is also dramatic. The risk of internal health problems because their cardiovascular systems will have to work harder. 
Global warming increases ozone in the atmosphere, which can cause lung damage.