Tonight, my friend Norine and I had the privilege of screening some excerpts from Ken Burns’ newest documentary, The National Parks: America’s Best Idea.

What can I say? The man is a poet. He imbues each of his films with such a genuine love for the subject that I can’t help but be drawn in.

Never mind that I don’t follow baseball, or that my high school music teacher forever ruined jazz for me. Ken Burns’ films transcend my tastes and personal history. Which is why—even if you’re not a nature-lover—I highly recommend tuning in for The National Parks on PBS, beginning September 27.

I also highly recommend hearing Will Steger speak, if you get the chance.

Will was the keynote speaker during the second half of the evening. At first I thought it a rather odd juxtaposition that the famous polar explorer should be talking about global warming after the screening of a Ken Burns film. But gradually, it started to make sense.

The U.S. National Parks system was begun several generations ago as a means of preserving those incomparably beautiful, wild areas for future generations. Back then it was a rather daunting task.

Now, we’re faced with the challenge of preserving the planet for future generations—a VERY daunting task.

Most of the photos and statistics Will presented were pretty grim. If the data are correct, global warming is already far more advanced than most of us realize.

Thank God I was sitting next to Norine. Earlier in the evening, I’d been fretting about where we’d parked our bikes. “What if I can’t see the lock combination in the dark? What if we can’t unlock our bikes for the ride home?” I asked. “Imagine the best-case scenario,” replied Norine.

She whispered the same thing in the auditorium as I shot her a worried look.

Imagine the best-case scenario. There is still hope. If each of us makes only one small change, imagine the power our collective actions could have.

I’ve vowed to make one small change. What will you do to stop global warming?

Here are 50 ideas to get you started.