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.

There are a few obvious consequences and perhaps one subtle possibility. One obvious thing is that, to stimulate the economy, President Obama has committed to creating millions of green jobs that will leave a legacy - much as Roosevelt's public works did during the new deal.

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

These are not exhortations from overwrought extremists, but carefully phrased warnings from some of the world's finest scientists.

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.

The easiest way to make something cool is to get cool people to do it. Part of this might mean the president has to forget tensions with opponents, or people like Arnold Schwarzenegger who has actually been decent with oil issues. Maybe he needs to pull some of the cool people in and make them model the right behaviors.