In the New York Times, Gina Kolata reports on recent work to test the implications of obesity for global warming. The findings: American weight gain has made driving more common (for those who can barely walk) and plane flights less efficient (with bigger seats and fewer passengers). In total, it costs us 1 billion gallons of gasoline per year, and all the attendant CO₂-emissions. After the OPEC embargo of the early 1970s, health economists had a slightly different focus: A potential solution to the energy crisis was floated in a 1978 paper called "The energy cost of overweight in the Unites States." (It's not clear if these studies take into account the energy savings associated with obesity, in the form of a smaller population.)