What is the world wide yearly average temperature?

Question

from Al Gore's An Inconvenient Truth

Answer 1

About 15 degrees celcius.

Answer 2

actually the air temperature are vary between time and location.. so its difficult to us to generalize that..

but based on inconvenient truth by Al Gore Since around 1860 until 2007, the average air temperature near the earth’s surface has risen about 1.3 degrees Farenheit. If the temperature continues to rise at the current rate, some scientists (and politicians!) are predicting that the average air temperature near the earth’s surface could be as much as 6 to 11 degrees higher than now by the year 2100 A.D..