I can't cite a source, but I remember "learning" when I was a kid that an early-20th-century Farmer's Almanac predicted that soon enough, the streets would be made impassable by all the horseshit from all the horse-drawn carriages. What the writer didn't envision, of course, that an unseen development would change the course of everything.

I think of that this morning because of this, a front-page story in the Globe about athletes' concerns about air quality at the Beijing Olympics this summer. I've known for years — and, duh, so did the International Olympic Committee — that air quality in Beijing is so bad that it is often one of the first comments a recently returned visitor will offer.

But now that Ethiopian distance-running legend Haile Gebrselassie has said he's going to skip the marathon because he's concerned about his career and even his health, he brings an opportunity to the world to focus on what sulfurous-coal burning can do for quality of life.

I see now that the Olympics won't just be a showcase of the world's best athletes, it will also be a chance for TV viewers worldwide to see street scenes of all the antiquity set against all the new construction, while in the foreground, people will be walking around with face masks trying to filter our all the particulates. And for commentators to talk about how unprepared they were for the shortness of breath they experience sooner because of the bad air quality.

In this country, especially, things like that have the potential to raise the consciousness of people who still aren't focusing on how environmental degradation will actually degrade their lives.