What is global warming?

Global Warming is defined as the increase of the average temperature on Earth. As the Earth is getting hotter, disasters like hurricanes, droughts and floods are getting more frequent.

The observed and projected increases in the average temperature of Earth's atmosphere and oceans. The Earth's average temperature rose about 0.6° Celsius (1.1° Fahrenheit) in the 20th century, see temperature graphs below.



Fig. 1: Definition for global warming: Temp. increase in the last 1'000 years (graph from http://www.globalwarmingart.com/images/b/bb/1000_Year_Temperature_Comparison.png)




Fig. 2: Definition for global warming: Temp. increase in the last 150 years (graph from http://www.globalwarmingart.com/wiki/Image:Instrumental_Temperature_Record_png)




Fig 3: Definition for global warming: Temp. increase in the last 25 years (graph from http://www.globalwarmingart.com/images/a/af/Short_Instrumental_Temperature_Record.png)


Prediction for future temperature increase (global warming predictions)
According to different assumption about the future behaviour of mankind, a projection of current trends as represented by a number of different scenarios gives temperature increases of about 3° to 5° C (5° to 9° Fahrenheit) by the year 2100 or soon afterwards. A 3°C or 5° Fahrenheit rise would likely raise sea levels by about 25 meters (about 82 feet).




Fig 4: Definition for global warming: Temp. increase until the year 2100 (graph from http://www.globalwarmingart.com/wiki/Image:Global_Warming_Predictions_png.