Well, I said the train is less polluting than airplanes. I think that is, it could be, if trains were fuller, if the fuel was cleaner (or the train track electrified). But the pollution isn't placed high in the air. This dark smoke appeared only when the train was straining to start, or going uphill--and there are a few squashed bugs on the windows, which were actually quite clean for most of the trip. The prairies were so flat and the sky so big, of course, something you know but again have to experience, mile after mile (and the mile signs were in miles, not kilometers). I sat in "Comfort Class," which is the term for coach, which I have to admit was pretty comfortable--and $1,000 cheaper than a sleeper. The service was fine. I was late to get on and got whisked down the platform by VIA staff. Leaving Jasper, a young couple had failed to return to their seat, so the train stopped while a truck raced to get them on board. Such service! Compare that to your airline.