Jeppen, the first Great Depression was temporary - it ended with the Japanese invasion of China in 1937 and the German invasion of Poland in 1939. You say 'there is a lot of room to rearrange current energy consumption to allow for added growth.' This does not contradict my point, the economic problem is not rearranging current energy consumption, it is coping with falling energy consumption. And energy consumption is falling because energy has become too expensive. Economic growth could only take place in this situation if society and industry became more energy efficient and at the moment this is not happening enough. However, I agree with you that growth is (sometimes) a function of technical progress; but nothing short of molecular engineering will get us out of this predicament. On that note: www.myidea.net/ideas/node/326