what is global warming?

Global warming is a gradual increase the planet’s average ground and atmosphere temperature across whole earth. Studies have showed that the global temperature has increased by one degree in the past century.
The human activities have increased the carbon dioxide (CO2) and other green gasses and that the beginning of the risk. The scientists believe that a rise of (CO2) will lead to further global warming. The human activities are partly responsible of what have happened in last the century by producing the green gasses.
The climate has changed in the most earth areas. The number of the hurricanes increased, ice caps melting as satellites images approved. The deserts spots become larger. The scientists say it would be worst if the humans did do thing to stop the disasters which may happen in five decades further.