Despite the international scientific community's consensus on climate change, a small number of critics continue to deny that climate change exists or that humans are causing it. Widely known as climate change "skeptics" or "deniers," these individuals are generally not climate scientists and do not debate the science with the climate scientists.

Any politician or scientist who tells you these [GMO] products are safe is either very stupid or lying.

For the sake of our health, our children and grandchildren and even our economic well-being, we must make protecting the planet our top priority.

Humanity is facing a challenge unlike any we've ever had to confront. We are in an unprecedented period of change.

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.

When I was a kid, being outside was the norm. Rain or shine, our parents would tell us to get out of the house.

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.'