What is Global Warming? Overview

So what is global warming?
Global warming is an increase in the average temperature of the surface of the Earth (air and oceans) over the last 100 – 200 years.

Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level.
IPCC Climate Change 2007 Report (1)

Global Warming: Earth on Fire

What is Global Warming C O N T E N T S Global Warming Overview Rise of Global Surface Temperature Rise of Global Sea Level The Science of Global Warming Case Study: Arctic Ice Cover Shrinkage Conclusion

Global warming is quite a recent phenomenon that came to international prominence only by the end of the 20 th century.

But man-made pollution was known to affect the climate system of the planet as long ago as the middle – end of the 19 th century.

It was first suggested in 1863 that changes in the composition of the atmosphere due to pollution could lead to climate change. In 1896 the Swedish scientist Svante Arrhenius made first actual calculations of the effect of greenhouse warming in which he estimated that a doubling of carbon dioxide [in the atmosphere] would increase the global average temperature by 4 ° C to 6 ° C. (2)

As a general guidance, we identify the following three main indicators of global warming:

• Rise of air and ocean temperature,
• Rise of global sea level, and
• Loss of snow & ice cover