Carbon tracks.

• Position: MATTERS OF SCALE - Table

Estimated carbon emissions per passenger-mile traveled (grams of [CO.sub.2]): Automobile 130-390 Commercial -jetliner 180-280 Bus 110-190 Train 100-180 Walking (if all calories came from top sirloin) 900-1,600 (from ground beef) 500-1,500 (from 2% milk) 200-400 (from apple) 50-100 (from typical U.S. diet) 160 (from vegan diet) 30 Cycling (all calories from top sirloin) 500-900 (from ground beef) 300-500 (from 2% milk) 100-200 (from typical U.S...