Or how to pick winners in a hurry. The winners in question are likely to include everything from new economic systems which are genuinely sustainable through high and low technologies to all kinds of societal and individual behaviour change.
We know that large changes are going to arrive because sooner or later we are going to have to power civilization on straight sunlight as the stored sunlight of fossil fuels runs out. Are we reaching the beginning of that transformation now as the energy realists believe, or do we have all kinds of unconventional fossil fuels that we shall be able to tap for another few decades?
The smart money, what's left of it, is starting to lean towards energy realism, for a whole host reasons including economic and geological. As that happens, the question of which civilizational techniques and technologies to back really becomes critical. The next question will be: how on earth shall we judge what will work and what will fail? Who should be helped to produce what innovations in industry, society, governance? It is quite clear that help will be needed, and as luck would have it, getting help from the government is suddenly all the rage. Humans became homo technicus (I apologise for the neologism) a long time back - perhaps 35,000 years ago - and now we rely on technology for almost every aspect of daily survival.
Here in California, one of the world centres of solar and green technology, the question is particularly pointed: how to help many kinds of green and clean technologies, experiments and, one must hope, potential solutions. Venture capital is suddenly very shy and both consumers and credit are squeezed like a Victorian girdle. As with so many other things in this brave new world of the last five minutes, all eyes are on government as the last hope. It does seem rather like a death-bed conversion, but if the economic crash can re-introduce the idea that government is necessary for civilisation - good government that is - then that may help us judge not only what technologies to help, but also what paths society should try to follow as it deals with limits to growth arriving earlier than even the soothsayers of the Club of Rome envisaged.