The average surface temperature of the Earth increased over the 20th century by 0.6C and, as it continues, a level of 1C increase is nearing. An increase of one degree celsius across the planet's surface means huge changes in climatic extremes. The projections for the scenarios we are likely to be facing in the  coming centuries can be correlated to temperature increases of 1 to 6 degrees celsius.

The Hadley centre calculates that a 1 degree increase would eliminate fresh water from a third of the world's land surface by 2100. Deserts would reappear in the mid-west United States as sandstorms move across miles of former prairie.

Low lying atoll countries like the Maldives will see sea levels rise and mainland coasts like the Gulf of Mexico will see stronger and stronger hurricanes as the ocean warms. While these areas may still be on the brink, the Arctic may already have passed the point of no return, with the disappearance of 720,000 square kilometers of supposed permanent ice in one year.