Build high-speed, electrified trains over the most-traveled corridors. It'sreally hard to power carbon-free airplanes, but electrified trains are much easier. We'll be a half century behind the Japanese, but better late than never.

I feel more confident than ever that the power to save the planet rests with the individual consumer.

Earth Day gathered up those strands, and dozens more, and knitted them together in the public consciousness as "environmental" issues. The nation was pretty startled when 20 million people hit the streets. Congress, which had adjourned for the day to go back to its districts, was blown away.

With time environmental issues got much more complicated. It is pretty easy, if you know what you are doing, to stop a company from pouring poison into a lake where kids swim. It is much harder to address all the myriad greenhouse gases emitted by different sources - from petrochemical refineries to hundreds of millions of peasants cutting down trees for their incredibly inefficient cook stoves.

We shouldn't fuel the future with the polluting methods of the past, ... We have the technology to power our future in ways that don't threaten our health or poison our planet. Let's choose to use it.

Environmentally, business in America in 1970 was very similar to business in China today. Even if a CEO wanted to be a responsible corporate citizen, he (and they were all "he's" then) simply couldn't invest a billion dollars in pollution controls to produce a product that was indistinguishable from those of his competitors. His products would be priced out of the market. Passing laws that created a clean, level playing field for whole industries had to be a core focus of the 1970s.

By the year 2000, such renewable energy sources could provide 40 percent of the global energy budget; by 2025, humanity could obtain 75 percent of its energy from solar resources.