Battering down solar cells on the roofs of Wal-Marts in California. I think that will be some of the highest-return investments that anyone ever makes.

The language "it's too late" is very unsuitable for most environmental issues. It's too late for the dodo and for people who've starved to death already, but it's not too late to prevent an even bigger crisis. The sooner we act on the environment, the better.

I hate gold. It does not pay a dividend, it has no value, and you can't work out what it should or shouldn't be worth," he said. "It is the last refuge of the desperate.

Think how weird profit margins are: We've got high unemployment and financial crises - and world record profit margins. People think the American market is very cheap. We don't. The market quite incorrectly gives full credit to today's earnings.

Volatility is a symptom that people have no idea of the underlying value-that they have stopped playing the asset game. They're not buying because it's a company with certain attributes. They're buying because the price is rising. People are playing games not related to any concept at all of what the long-term value of the enterprise is. And they know it.

Everyone asks about gold. This is the irony: just as Jim Grant tells us (correctly) that we all have faith-based paper currencies backed by nothing, it is equally fair to say that gold is a faith-based metal. It pays no dividend, cannot be eaten, and is mostly used for nothing more useful than jewelry. I would say that anything of which 75% sits idly and expensively in bank vaults is, as a measure of value, only one step up from the Polynesian islands that attached value to certain well-known large rocks that were traded.

The potential for alternative energy sources, mainly solar and wind power, to completely replace coal and gas for utility generation globally is, I think, certain. The question is only whether it takes 30 years or 70 years.