Producing beef for the table has a surprising environmental cost: it releases prodigious amounts of heat-trapping greenhouse gases
Burgers or Tofu?
Annual beef consumption per capita varies from 120 pounds in Argentina
and 92 pounds in the U.S. to only a pound in the small eastern European
country of Moldova; the average is about 22 pounds per person per year. The
colors of the countries and the distortions of their usual shapes reflect
the amount by which beef consumption per capita varies from the world
average. World beef consumption per capita is growing, particularly in Asia,
because of economic development: as people earn higher incomes, they
purchase foods they find more desirable.
Eating and Driving: An Atmospheric Comparison
The greenhouse gas emissions from producing various foods can be
appreciated by comparing them with the emissions from a gasoline-powered
passenger car that gets 27 miles per gallon. The estimated emissions from
food production incorporate the assumption that 1,000 kilograms of carbon
per hectare per year (about 2,700 pounds of carbon dioxide per acre per
year) would have been absorbed by forests or other vegetation if the land
had not been cleared for annual food crops or fodder. Greenhouse
gases—carbon dioxide (CO2) and methane, for instance—trap solar energy and
warm the earth’s surface. Quantities of greenhouse gases are often expressed
as the amount of CO2 that would have the same global-warming potential:
their CO2 equivalent.
The High (Greenhouse Gas) Cost of Meat
Worldwide meat production (beef, chicken and pork) emits more atmospheric
greenhouse gases than do all forms of global transportation or industrial
processes. On the basis of data from the United Nations Food and Agriculture
Organization (FAO) and the Emission Database for Global Atmospheric
Research, the author estimates that current levels of meat production add
nearly 6.5 billion tons of CO2-equivalent greenhouse gases every year to the
atmosphere: some 18 percent of the worldwide annual production of 36 billion
tons. Only energy production generates more greenhouse gases than does
raising livestock for food.
A Growing Appetite
World beef production is increasing at a rate of about 1 percent a year,
in part because of population growth but also because of greater per capita
demand in many countries. Economic analysis shows that if all beef were
produced under the economically efficient feedlot, or CAFO (concentrated
animal feeding operation), system—which generates fewer greenhouse emissions
than many other common husbandry systems do—beef production by 2030 would
still release 1.3 billion tons of CO2-equivalent greenhouse gases. If
current projections of beef consumption are correct, even under the feedlot
production system the buildup of CO2-equivalent greenhouse gases could
amount to 26 billion tons in the next 21 years.
Prime Cuts: How Beef Production Leads to Greenhouse Gases
The largest fraction of the greenhouse effect from beef production comes from the loss of CO2-absorbing trees, grasses and other year-round plant cover on land where the feed crops are grown and harvested. Second most important is the methane given off by animal waste and by the animals themselves as they digest their food. This analysis of the U.S. feedlot beef production system was done by ecological economist Susan Subak, then at the University of East Anglia in England.
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