Dear Umbra,

My girlfriend recently made a trip by train (about 600 kilometers, I’d guess), and it made me wonder just how much more ecological it is to travel by train instead of by car. What’s your take on this?

Ottawa, Ontario, Canada

Dearest Canadian Michael,

The train, it is better. The car, it is the worst. That is my take, and I found a legitimate source that agrees — namely, my favorite book. Let’s all recite together: The Consumer’s Guide to Effective Environmental Choices, from the Union of Concerned Scientists.

All aboard.

Photo: Gareth Hill.

The UCS compiled its research, and the research of others, into an easy-to-understand table on page 57 of the paperback edition (for those of you who are following along at home). The table includes trains, airplanes, cars and trucks, motorcycles, and intercity buses. I’ve tried to understand original mobile-source emissions data from various government sources and, let me tell you, I’m concerned, but I ain’t no scientist. We want data per passenger mile, and we want it for a huge range of information. How much fuel is consumed? How many people are on the typical run from Quebec to Ottawa? Do we measure only greenhouse gases? How about the impact of manufacturing trains and automobiles? What about the small pretzel packets on the train vs. the large bag of potato chips in the car?

Praise Hermes, the UCS is here to help. It evaluated the impacts of different forms of transport in terms of global warming, air pollution, water pollution, and habitat alteration. Trains definitely come out ahead of cars, with better ratings in all subcategories except common air pollution and land use. (Data are for U.S. trains, by the way. Canadian rail may have better emission controls that bring the air pollution number down.)

But the important take-home message is that your girlfriend is a righteous eco-head. Second important take-home message: Buy the book. It’s $15 U.S., $21 Canadian. Easy to read, simple charts even a research assistant can understand, and chock-full of answers to the questions that stuff my mailbox. I’m happy to remind you all about it every few months, but I think you’ll be happier with me and with yourselves if you each get a copy of your very own.