The climatic advantages of pigging out.

The climatic advantages of pigging out

Growing carbon dioxide emissions -- principally from fossil-fuel combustion and deforestation -- represent the major human contributions toward a futre global warning. The beefy diets typical of Western industrial countries exert a less obvious, but still potentially serious, influence on climate warming, says energy analyst Florentin Krause, who calculated their effects while investigating greenhouse-gas releases for a Dutch-sponsored study (SN: 12/2/89, p.359).

Modern cattle-raising practices require setting aside large plots of land for pastures and feed-grain corps--land that might otherwise host carbon-storing forests, observes Krause, of the Lawrence Berkeley (Calif.) Laboratory. Reforesting that land would just about offset the deforestation needed over the next 30 to 50 years to create enough croplands to feed rapidly growing populations in developing nations, he calculates.

Per capita beef consumption is about 170 pounds per year in industrialized countries -- almost six times higher than in developing lands. Moreover, while beef demand over the past 20 years has remained stable in developing countries, it has climbed an average of 1 percent annually in industrial nations. "To meet global targets for climate stabilization," Krause contends, beef lovers may need to halve their beef consumption, planning more menus around less resource-intensive proteins.

Though vegetable sources offer a good alternative, concerned individuals need not eschew meat, he says. Producing pork takes only 10 to 30 percent as much feed as beef per unit of protein, he notes. A dietary shift to pork would offer another bonus: lower barnyard emissions of methane -- a far more potent greenhouse gas than carbon dioxide. "Anywhere from 5 to 9 percent of what a cow eats goes up in [methane] gas, compared to an average of just 1.3 percent in pigs," Krause explains. In fact, his data suggest cattle production for meat and dairy products represents at least 5 percent of the global-warning contribution from human activities.

Though chickens produce even less methane per unit of protein than pigs, overall a switch from beef to chicken would provide less climatic benefit. The reason? Per unit of protein produced, these birds "are about as grain intensive as cows," Krause says.