Last month we wrote about ultra-processed foods to figure out just how significant they are to climate change (answer: less than many people assume). Some readers loved this article, and others didn’t, so this month I wanted to address the main point of critical feedback we received. This is the distinction between sustainable diets and climate-friendly diets.
In the post on ultra-processed foods, we pointed out that dietitians believe that reducing ultra-processed foods is the most impactful thing we can do to make the food system more sustainable. I still believe this is a false assumption we’re making, but in that post we made the mistake of conflating “sustainable” with “climate-friendly.” The difference between sustainable and climate-friendly is important, because “sustainable” captures so many different factors, can be measured with lots of different indicators, and there are often interesting, difficult, and complicated trade-offs between those factors. What’s climate-friendly (low greenhouse gas emissions) might not be what’s best for fresh water use, or for local soil quality.
For example, among livestock, cows are ruminant (produce methane in digestion) and pigs are not, so producing beef is much worse for the climate than pork. However, pigs also produce lots of manure and can pollute local air and waterways with their waste. This means that switching from beef to pork is likely to reduce your climate footprint, but might cause more local pollution (depending on how it’s managed on the farm). Many of these trade-offs are hard to measure and vary by farm, making “sustainable food” complex and invisible to consumers who cannot visit farms or view the entire supply chain.
You might know that we’ve pushed back against popular claims about local food. Most people assume that local food is more climate-friendly than global food, because intuitively it demands lower transportation distances, and so should generate less emissions. But as we’ve talked about often, this isn’t the case when emissions are actually measured, and local food can in fact be worse for the climate, because growing conditions are crucial to things like fertilizer use. This is a surprising finding for climate activists and foodies, but the research has been replicated many times now and reliably finds the same result. However, it’s possible that local food has sustainability benefits, such as educational opportunities at local farms, which may help people learn about growing produce or livestock, for example. I think this means that we could explore the wider sustainability benefits of local food, but that we should not be focused on the procurement of local food as a climate action. I also think we should be clear about what specific goals we have when we promote local food.
One analogy is to think about “sustainable” food as similar to “health.” It’s difficult to make any general statements that apply in all cases as “healthy.” Sure, most people should eat more veggies and fruit, but this advice is complicated for people with irritable bowel syndrome or kidney disease, or people who are struggling with disordered eating. Mental health, social determinants of health, and other factors tend to complicate our nutrition messaging. I think a similar issue happens with sustainability as a very broad goal–there are many factors to consider, and it’s hard to make generalizations.
This is one reason that when we set out to establish Drawdown Dietetics, we wanted to focus on climate change within sustainability, so we can be specific and clear when interpreting the research evidence, and to help us put out recommendations for action. The downside of this strategy is that our messaging and recommendations may come across as simplistic or ignoring other areas of sustainability. I recently listened to a podcast on animal welfare and factory farming, which is long but excellent, and the speaker describes a problem of British grocery chains being so focused on their climate goals that they’re unwilling to make even small changes that would benefit farm animal welfare, because it might increase greenhouse gas emissions. This is clearly a problem.
All of this said,
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Climate change is an immediate, urgent threat that absolutely needs to be addressed as quickly as possible. We see our role as continuing to understand and communicate where dietetics could be addressing climate change more effectively. If there are trade-offs, those need to be noted so a decision can be made, but it’s still crucial that we look at greenhouse gas emissions data to support work dietitians and others do in various settings.
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The beauty of our two main recommendations–plant-rich diets and reduced food waste–is that they are pretty generalizable across the board for climate change and sustainability. If we waste less food, less food of all kinds needs to be produced in the first place, so every environmental indicator benefits. Eating less meat and more plants also means affecting all, or almost all, environmental indicators. A vast amount of Earth’s land mass is now dedicated to raising livestock or to growing crops to feed that livestock. Switching from meat to plants essentially guarantees we’re using less planetary resources and causing less pollution. Less food waste and more plant-rich diets means food that is more sustainable and more climate-friendly.
The data visualization below has helped me to grasp the scale and significance of our current meat-centric diets in rich countries:
You read that right: 77% of all agricultural land produces 18% of the world’s calories through meat and dairy.
At the moment, we are destroying the world’s forests and other wild spaces to make room for farm animals. No matter which indicator you look at–land use, chemical use, pollution, soil health, or biodiversity–this issue should be well known among dietitians.
Reducing ultra-processed foods will not do nearly as much for the environment as helping people to eat less meat and more plants, and wasting less food everywhere we work.
For a wider perspective than this one, the ICDA Sustainability Toolkit has added a couple of interesting pieces on UPFs and their environmental impacts, published in the Journal of Cleaner Production. These articles cover the environmental impacts for UPFs beyond greenhouse gas emissions.
Thanks for reading! Keep sending us your thoughts and feedback! And if you have a question about food and climate change, email us at [email protected] and we might be able to answer it in a future post.
Anneke