It's all about sustainable development. When water is almost free, people move to the desert, put in golf courses and lawns and all sorts of things that use huge amounts of water. When gas is cheap, people move to the suburbs and opt to commute to work in gas guzzlers. When climate change is not a concern, we build coal-fired power plants, bigger houses, and use more air conditioning. Almost none of those developments is good.

One thing hasn't changed. The microeconomics I learned in the 70s still applies. People really do make decisions based on a rough cost-benefit analysis. If we pay the true cost of the water we use, the gas we consume, and the carbon we expel, we might actually make decisions that result in sustainable lifestyles.

In 1976 I campaigned for Morris Udall, who lost to Jimmy Carter in the Democratic primaries. I was impressed with his environmental positions, which included radical ideas like taxes to raise the cost of gasoline to decrease its use. Such taxes are anathema to most Americans. Now, we have gas prices high enough to cause a real change in behavior, with the profits going to the robber barons of the 21st century, the oil companies. Where would we be had we followed Udall's positions for the last 30 years?