Well, in the short term, the demand for oil is inelastic, that is, it doesn't respond much to price changes. And so, when there are fluctuations in availability of oil, you get these big spikes and movements in oil prices. And we've seen quite an increase in oil prices over the last few years, as you know.
Over the longer term, higher oil prices actually have a benefit, which is they encourage conservation and they encourage alternative supply sources.
Coal, of course, is actually a very promising source. It's, of course, a traditional source of energy, but assuming we can find ways to address the environmental implications, and there are many promising directions there, coal could be a very big part of our energy diversification in the future.
So my expectation is that as long as the markets are allowed to work, together with some support for research and development from the government, together with clear and effective regulation, that we will solve our energy problems and that that solution is going to come not just from one single magic bullet, it's going to come from a wide variety of different alternative sources, including, I think, coal.