I have always been fascinated with those who try to look over the horizon and see things that are coming at us.

I've learned the importance of changing people's minds at the grassroots level so that whoever does run will have a much better chance of encountering public opinion that reaches a critical mass and brings about a change not only in White House policies but in the Congress and in the state legislatures and all around the world.

The signs that the world is spinning out of kilter are increasingly difficult to misinterpret. The question is how to convince enough people to join a critical mass of urgent opinion, in the U.S. and the rest of the world.

CO2 is the exhaling breath of our civilization, literally... Changing that pattern requires a scope, a scale, a speed of change that is beyond what we have done in the past.

Often, sustainability is discussed only in the context of energy. Energy sustainability is essential - but the word has a much broader meaning. It means long-term thinking about how we manage our businesses, invest in social spending, and plan for the future. This requires vision and leadership, and it requires citizen engagement.

New England has a harsh climate, a barren soil, a rough and stormy coast, and yet we love it, even with a love passing that of dwellers in more favored regions.

My father's generation's crisis was fighting fascism. Ours is fighting climate change. It is much harder because you can't see it, it is not an obvious threat. But the solution is in our hands.

The Moon stabilizes Earth's obliquity. Well, almost. The tilt actually varies between 22 and 24.5 degrees - and the variation is enough to induce such environmental inconveniences as the occasional ice age. Without the Moon, it might be much worse.