Do you ever find yourself standing still in a grocery store, overwhelmed by choice? I do. Frequently. Our food system is complex, and considering the health, economic and environmental trade-offs involved in choosing products can be a challenge. As an intern at the David Suzuki Foundation, I spent my summer reviewing the published scientific literature on the environmental impacts and trade-offs between different protein sources. Chicken versus beef versus fish versus pork versus plant-based proteins... Which is better, you ask? Well, here are a few things I have learned:
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1. Trying to compare the environmental impacts of different dietary proteins is not easy
This is especially true when trying to compare land-based protein (e.g., beef, chicken or pork) to aquatic protein (e.g., fish or shellfish). All food-production systems have an environmental impact, but they don't all have the same type of impact. Carbon emissions are a big concern in beef production, biodiversity impacts are a big issue with most types of trawl gear, and the ecological impacts of feed are a problem in farming carnivorous fish. Trying to compare these impacts is like trying to compare apples to oranges; they are kind of the same, but totally different.
2. Trying to compare the environmental impacts of different dietary proteins is not easy... but researchers around the world are doing it
Creating a balanced picture that allows us to compare the environmental impacts of different protein-production systems is necessary so that governments, consumers and producers can make informed decisions. As such, researchers, non-governmental organizations and governments around the world are applying different methodologies to try to compare proteins. Life-cycle analysis (LCA) — a quantitative assessment tool used to evaluate the environmental effects of a product throughout its lifecycle from production to landfill — is the most commonly used assessment method. Many other comparative methodologies exist, however, and they all have associated benefits and drawbacks. No single methodology will be able to provide a complete picture, but they are a good start and if combined could lead to strong results.
3. What the research is saying about environmental impacts of different dietary proteins
Research has focused mostly on comparing the global warming potential of producing different proteins; that is, the amount of greenhouse gases emitted per unit of meat production. Generally, from this perspective lamb and beef have substantially greater impacts than legumes or shellfish, while chicken and finfish fall somewhere in between. There is significant variation in the data, however, due to differences in production systems, management and regulations, and the plant or animal that is being produced. And while greenhouse gas emissions are important to consider, they represent just one of many environmental impacts of protein production. Some studies examine land, water and nutrient use as environmental impact indicators, but these studies are less common.
4. Beef, chicken, fish, pork, tofu, beans... Which should you choose?
Unfortunately, after four months of research I still don't have a definitive answer, but an easy place to start is by eating less animal-based protein. A 2011 report by the Environmental Working Group found that eating one fewer burger every week for a year was the equivalent of taking your car off the road for more than 500 kilometres, and if everyone in the U.S. ate no meat or cheese just one day a week for a year it would be equivalent to taking 7.6 million cars off the road. People are starting to take notice of the environmental and health benefits of this. The City of Vancouver, for example, proclaimed June 12 to be Meatless Monday, making it the first in Canada to take action on this issue.
When you pick a protein, a good rule of thumb is the lower down the food chain the less likely the environmental impact... legumes and shellfish are a good bet!
5. Want to know more about the environmental impacts of different dietary proteins?
Check out our Food and Climate Change page for more information and how you can be part of the solution.