With the world's human population now at seven billion and growing, and the demand for technology and modern conveniences increasing, we can't control all our negative impacts. But we have to find better ways to live within the limits nature and its cycles impose.

With an estimated population of nine billion people by 2050, we cannot continue to consume resources at the same rate and maintain our quality of life.

Doing all we can to combat climate change comes with numerous benefits, from reducing pollution and associated health care costs to strengthening and diversifying the economy by shifting to renewable energy, among other measures.

The environment is so fundamental to our continued existence that it must transcend politics and become a central value of all members of society.

If we continue to set human borders and the economy as our highest priorities, we will never come to grips with the destructiveness of our activities and institutions.

Most North Americans know that human-caused global warming is real, even if political leaders don't always reflect or act on that knowledge.

Environmentalism isn't a discipline or specialty. It's a way of seeing our place in the world. And we need everybody to see the world that way. Don't think 'In order to make a difference I have to become an environmentalist.'