A new study has found that the environmental impact of beef production is significantly worse than that of dairy, poultry, pork and eggs. According to one expert, cutting down on red meat would actually have more impact on carbon emissions than abandoning cars. The study has been published in Proceedings of the National Academy of Sciences.

Livestock production is known to have serious impacts on the environment; it affects air and water quality, ocean health, competes with biodiversity and is the largest land user in the world. It also affects global food security given the fact that the crop calories fed to animals for human consumption are sufficient to meet the calorie needs of 4 billion people, which is concerning since it has been estimated that we need to grow 70% more food by 2050. Furthermore, it is responsible for around 20% of global greenhouse gas emissions. However, quantifying the environmental effects of livestock has been a challenge but remains a necessity in order to highlight changes necessary in order to promote sustainability.

To address this issue, researchers quantified the impacts on land, irrigation water and greenhouse gas emissions for 5 livestock categories in the US: beef, dairy, poultry, pork and eggs. Lamb was not considered since consumption is relatively low in the US. They found that while the impacts were comparable for the last 4 categories, the impacts for beef were significantly higher.

Producing beef was found to require around 28 times more land than the other categories, 11 times more water and resulted in 5 times more greenhouse gas emissions. Furthermore, when they compared beef with other staples such as wheat and rice, the impacts were even more obvious with this meat requiring 160 times more land and producing 11 times more greenhouse gas emissions.

While the researchers accept that there are gaps in the data and that follow-up studies are required, they state that the take home message is clear: beef production requires significantly more resources than other livestock categories. They also go on to suggest that minimizing beef consumption would be an effective way to reduce the environmental impacts of our diet.

Cows are incredibly inefficient at converting grain to meat; the loss of 1 kilogram of beef has the same effect as wasting 24 kilograms of wheat. While not all cows are fed on grain, grass-fed cattle still have greater impacts on the environment than other livestock categories.

Meat consumption is a delicate issue for many, but the researchers are not saying that you should stop eating steak and burgers entirely; rather that reducing your intake will significantly cut your carbon footprint.

“Governments should consider these messages carefully if they want to improve overall production efficiency and reduce the environmental impacts,” Prof Mark Sutton at the UK’s Center for Ecology and Hydrology told The Guardian. “But the message for the consumer is even stronger. Avoiding excessive meat consumption, especially beef, is good for the environment.”

[Via The Guardian and PNAS]

[Header image "Steak!" by Sheila, via Flickr, used in accordance with CC BY-NC-ND 2.0]