Gourmets are often able to cite a personal epiphany, a moment of insight that irrevocably changed the way they looked at food. Often such stories involve France or Italy, an overachieving carafe of vin ordinaire and a budding romance.
In Mark Bittman's case, the mind-bending moment came two years ago, long after he had become a famous cook, when a United Nations Food and Agriculture Organization report titled Livestock's Long Shadow landed on his desk.
Mr. Bittman, the popular New York Times food columnist and author of several bestsellers, including How to Cook Everything, fixated on a statistic. Global livestock production accounts for one-fifth of all greenhouse-gas emissions - more than transportation.
"The global-warming thing was a catalyst," Mr. Bittman said by phone last week from Oregon, where he was travelling on business.