But is eating a vegetarian, or mostly vegetarian, diet better for the environment? This week, the Environmental Working Group (EWG) tried to answer that question with a new report on the environmental impact of farming.
The group's analysis of beef, chicken, pork, vegetable, and fish production concluded that beef produces serious amounts of climate-changing greenhouse gases, while vegetables do not. But it's not just beef that's heating up the plant. Fish production and cheese making are huge contributors of greenhouse gases, with farmed salmon and canned tuna emitting more than some forms of meat, and cheese generating more emissions than pork. (If you'd like to read the full report, view it on EWG's website).
For those who choose to eat meat, the report's authors stress that grass-fed livestock is the way to go (in agreement with a recent Department of Agriculture study finding that grass-fed cows produce fewer greenhouse-gas emissions). Not just because pastured animals are less polluting, but also because their meat is a healthier choice. Studies have found grass-fed beef has lower levels of saturated fat, higher levels of healthy omega-3 fatty acids, and more vitamin E, beta-carotene, and B vitamins.
Here are five other interesting facts the report revealed about farming and the environment:
#1: Lamb tops the list. In terms of greenhouse-gas emissions, lamb was the worst, generating 50 percent more emissions of greenhouse gases than beef production, and six times more greenhouse gases than producing chicken (which generated the lowest greenhouse-gas emissions of all the meat production analyzed). Sheep, like cattle, are ruminant animals that generate a lot of methane (a delicate way of saying they pass a lot of gas). And methane is a potent greenhouse gas—25 times more damaging than carbon dioxide. Lambs also produce less edible meat per pound of live weight than cattle do. It takes a lot of greenhouse-gas-emitting fertilizers and pesticides to raise the food lambs eat, compared to the small amount of meat a farmer can harvest from them.
#2: Much of farmed salmon (44 percent) is thrown away. Food waste accounts for 20 percent of meat and dairy's environmental impact, and farmed salmon has one of the highest waste rates. Considering that it takes up to five pounds of wild fish to feed a pound of salmon, there are a lot of fish being pulled from the oceans to feed salmon whose meat just gets thrown away. To cut down on food waste, whether it be salmon or other forms of high-greenhouse-gas-emitting meat and dairy, buy as much as you know you'll eat, and freeze any leftovers (here are a few tips on freezing cheese).
#3: Meat and cheese have hidden costs. A four-person family skipping meat and cheese one day a week is the environmental equivalent of not driving for five weeks. Behind lamb, beef, and cheese production are the two most greenhouse-gas-emitting foods Americans eat. All the corn and grain grown to feed conventional cattle result in high levels of methane, a potent greenhouse gas. And in some areas of the world, rainforests are being razed in order to raise more cattle. Such deforestation is the world's largest driver of climate change. One reason cheese generates such high emission levels is that it requires so much milk to produce it, and all that milk comes from gassy cows. Less-dense cheeses, such as cottage cheese, are less polluting.
#4: You can make beans less gassy, simply by cooking them using a pressure cooker. Most of the greenhouse gas emissions associated with meat are generated on the farm in the production of feed and the processing of the meat, whereas most of those associated with plant proteins like beans and vegetables are generated once you get them home, during the cooking and waste-disposal process. Using a pressure cooker cuts cooking time in half and reduces beans' greenhouse-gas emissions by 25 percent, the report found.
#5: Tomato season is great for the planet. This is probably the best news of the study. Of all the foods included in the analysis, only lentils ranked lower than tomatoes with regard to greenhouse-gas emissions. Just make sure you eat them! Waste accounted for a larger portion of plant-related emissions than meat's because decaying produce emits methane; 20 percent of tomatoes' emissions were attributed to waste. So eat, can, or otherwise preserve all those summer tomatoes before they go to waste!