For the global temperature, the input is ~99.98% light and a tiny amount of heat from the earth’s core etc, and the output is light to space. The earth receives ~174 petawatts 24/7 365 and you can't really hide energy on that scale for very long. (http://en.wikipedia.org/wiki/Earths_energy_budget) You can directly measure this stuff so it's not really a guess.

PS: He used "tera-watt scale" which is about as true as saying watt scale. Well he was only off by 1000x so it's not quite that bad.