[wcoenen]

As Moore said about exponentials: "It can't continue forever. The nature of exponentials is that you push them out and eventually disaster happens."

Global energy consumption in 2008 was estimated to be 474 exajoules. The energy received by the earth from the sun is 5 million exajoules. So the difference is about a factor 10,000.

Assuming that we find a replacement for hydrocarbons (fusion, thorium?) and a modest 2% growth rate, that means we're only log(10000) / log(1.02) = 465 years away from having to deal with an amount of industrial waste heat equivalent to a second sun shining onto our planet. This is obviously absurd. We'll run into serious problems that will stop our growth long before that.