The Daily Mail uncovers those dastardly scientists have been pulling the wool over our eyes for years and actually the planet's A/C is set to cool. Global warming is the unusually rapid increase in EarthâÂÂs average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels. The global average surface temperature rose 0.6 to 0.9 degrees Celsius (1.1 to 1.6ð F) between 1906 and 2005, and the rate of temperature increase has nearly doubled in the last 50 years. Temperatures are certain to go up further.