Humans have only been trying to measure the temperature fairly consistently since about 1880, during which time we think the world may have warmed by about
+0.6 °C ± 0.2 °C.As we've already pointed out, the estimate of warming is less than the error margin on our ability to take the Earth's temperature, generally given as 14 °C ± 0.7 °Cfor the average 1961-1990 while the National Climatic Data Center (NCDC) suggest 13.9 °C for their average 1880-2004. We are pretty sure it was cold before the 1880 commencement of record and we would probably not handle the situation too well if such conditions returned but there has been no demonstrable catastrophic warming while people have been trying to measure the planet's temperature. If we have really been measuring a warming episode as we think we have, then setting new records for "hottest ever in recorded history" should happen just about every year -- although half a degree over a century is hardly something to write home about -- so there's really nothing exciting about scoring the highest number when looking at such a short history.
Please read the whole thing, it is fascinating with handy charts. Anyway the whole point of this bit is to link you to a fun snippet from Orson Scott Card (via. Tim Blair my favorite Oz columnist):
How can you tell who someone's god is? You look to see whose name they invoke as the cause of all things, good or bad. By that standard, the god of the devout Left is Global Warming; here is the Psalm of Al, from which the faithful constantly quote (King James Version):
1. Great storms ravage our cities, and the wise man saith: Global Warming hath done this.
2. Drought keepeth all storms at bay, and the wise man saith: This also hath Global Warming done.
3. Global Warming maketh the oceans rise; it maketh deep snow to fall;
4. Flood and fire, feast and famine, typhoon and tornado, hail and lightning, all things good and bad that come from sky or sea, Global Warming hath made them all.
5. And when our homes are beneath the waves, we shall know that Global Warming in its wrath hath seen our sins.
6. For our vehicles that glut themselves on oil, for the trees we cut and land we clear,
7. For the cooling and heating of our houses, for the plowing and harvesting of our fields, we are punished.
8. Whenever we burn carbon and release it into the air, we shall know that Global Warming seeth it, and is wroth.
9. O man! Thou hast flouted the great god of the sky, and by three degrees of temperature we shall be burned,
10. For Global Warming is a jealous god, and small and annoying is man.