Do you have 12 hours to watch Ken Burns’ latest opus, which debuts Sunday on PBS? It’s about national parks. Yup, the filmmaker who explored the Civil War, World War II, baseball and jazz in such loving detail devoted the past six years to Yellowstone and his brothers. And Yogi Bear is nowhere to be found. Burns wants everyone to know that “The National Parks: America’s Best Idea” — America’s best idea is equal rights but let’s not digress — is not a travelogue or a nature film. It’s much bigger than that, the parks are an extension of democracy, and Burns burns with passion about the subject.

“What if there were no national parks? If there were no national parks, then the Grand Canyon would be lined with mansions, and you and I and, more importantly, our children would never get to see that view. If there were no national parks, then the Everglades would be drained and it would be filled with tract housing developments and golf courses — and the world’s most exquisite, diverse habitat would be lost forever.”

Baltimore Sun TV critic David Zurawik writes that the film has “beauty and brains,” and, if you watch the first half-hour you will be hooked. He glows over the opening 14-minute overture… “It’s an eye-popping, brain-boiling montage of the magnificence of nature as it exists in our national parks.”

OK, boil my brain, Burnsie.