The lapse rate or average change in temperature is about 6.5C/km which means we have to change altitude by a mere 15m per 0.1C change. Furthermore, it has come to my attention that whilst Father Christmas comes down many chimneys – which happen to be about 7.5m tall, there is no mention of him ever climbing up.
Thus there must be a net gain in global temperature which we can work out as follows:
There are 7billion people on earth. Assuming 3.5/household, that is 2billion households. Or the increasing in temperature experienced by father Christmas (who doesn’t climb out of the chimney) is
2,000,000,000 x 0.1 /2 = 100,000,000C