Climate change has emerged as perhaps the single biggest threat to the future of our planet and its inhabitants. While some may view it as a distant problem, its effects have already begun to take their toll.

Given the breadth and urgency of climate change and its impact, what actions can we as individuals take to mitigate this crisis? Just as consumers have switched to compact fluorescent light bulbs and are driving and flying less, each of us can, and must, take a closer look at the amount of meat, egg and dairy products we consume and how they were produced.

Indeed, the production of meat, eggs and milk is having a tremendous impact on the planet and plays a major role in climate change. In 2006, the United Nations Food and Agriculture Organization released a report that found that producing meat, eggs, and milk emits more greenhouse gases into the atmosphere than cars, SUVs and other vehicles.

The animal-agriculture sector contributes 18 percent, or nearly one-fifth, of human-induced greenhouse gas emissions. This includes deforestation for grazing farm animals and growing feed crops, industrial fertilizer production for corn and soybeans, farm animal waste storage and disposal, and significant energy expenditures on farms and in transporting live animals and finished meat, eggs and dairy.

While much of the discussion about greenhouse gases has focused on carbon dioxide, methane and nitrous oxide have even greater global warming potentials. One ton of methane has the global warming potential of 23 tons of CO2, and one ton of nitrous oxide has the global warming potential of almost 300 tons of CO2.

According to the U.S. Environmental Protection Agency, cattle raised for beef and milk production in the United States account for 20 percent of the nation’s total methane emissions. Some of these emissions result from enteric fermentation, which occurs during digestion in cattle. Methane is also emitted by farm animal manure.

From 1990 to 2005, U.S. methane emissions from pig and dairy cow manure increased by 37 percent and 50 percent, respectively. This elevation, according to the EPA, resulted from the shift towards rearing pigs and cows in larger facilities where liquid manure management systems (or “manure lagoons”) are increasingly used. During the same period, changes in the U.S. poultry industry – including confinement in high-rise houses and an overall increase in the numbers of birds raised for meat and eggs – contributed to a 10 percent rise in nitrous oxide emissions.

It is important to remember that all animal products are not equal when it comes to animal welfare or climate friendliness. Most of the nation’s 10 billion farm animals are warehoused by the hundreds or thousands in factory farms where they are treated like mere meat-, egg-, and milk-producing machines.

The U.S. Department of Agriculture and EPA estimate that confined farm animals generate approximately 500 million tons of manure annually, three times more raw waste than produced by Americans. Factory farm waste is notorious for polluting air and water, and these operations pose such a health threat to workers and communities that in 2003, the American Public Health Association began calling for a moratorium on these industrialized animal factories.

For individuals who choose to eat meat, egg and milk products, the most important buying decision is to stay away from items made from animals confined in factory farms. To avoid these products, it is generally safe to seek out organic items and products from animals who were raised outdoors on pasture.

The head of the Intergovernmental Panel on Climate Change – the group of scientists jointly awarded the Nobel Peace Prize last year along with Al Gore – recently said that three steps we should each take are to drive less, shop less, and eat less meat.

An article published last year in the leading independent medical journal, The Lancet, suggested that consumers reduce our individual meat intake both for health reasons and to combat climate change. The authors wrote that, for the world’s higher-income populations, greenhouse-gas emissions from meat-eating deserve the same scrutiny as emissions from driving and flying.

Indeed, we can make a difference – for animals and the environment – at every meal. We can avoid factory-farmed products; reduce our consumption of meat, eggs, and dairy; and replace animal products with vegetarian options. Every bite we take is an opportunity to make a difference.

Gowri Koneswaran is Director of Animal Agricultural Impacts for the Humane Society of the United States and co-author of “Global Farm Animal Production and Global Warming: Impacting and Mitigating Climate Change,” an article to be published in a forthcoming issue of the journal Environmental Health Perspectives. She will be giving a free presentation at 7 p.m. on Wednesday, April 9 in the Bell Museum Auditorium.

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