The symbolism - and the substantive significance - of planting a tree has universal power in every culture and every society on Earth, and it is a way for individual men, women and children to participate in creating solutions for the environmental crisis.

Third world nations are producing too many children too fast...it is time to ignore the controversy over family planning and cut out-of-control population growth.

Some people accuse me of exaggeration, so let me be clear. Those people seek nothing less than the complete and utter destruction of the American way of life.

Because these consequences are distributed globally, the problem masquerades as a distraction. Because the length of time between causes and consequences stretches out longer than we're used to dealing with, it gives us the illusion that we have the luxury of time. Neither of those things is true.

I have felt for a long time that the pathway to solving the climate crisis is through the building of a massive grassroots army of men and women who will go out there and win the conversation on climate, and persuade businesses, and universities, and towns to switch to renewable energy and to reduce emissions. And the big change from ten years ago is that people are way more receptive, not only to the message that we have to act, not only to the message that now we can act, we have the solutions now - that's the biggest change - but also willing to make a commitment that we will act.

American democracy is in grave danger from the changes in the environment in which ideas either live and spread or wither and die.

Consider what kind of car you get. Buy cars and other products that have the least impact environmentally.