Cutting the carbon from your diet
I’ve been digging more deeply into the question of what you should eat if you’re looking to lower your carbon footprint. I’ll have a few posts on this topic coming up, because it’s one of those vexed issues with lots of tradeoffs and corner cases and tricky considerations. But let’s start off by keeping it simple: eat less red meat and dairy.
A lot of people, myself included, happen to enjoy eating meat and dairy. Take solace in fact that “less meat” isn’t necessarily the same as “no meat.” Take further solace in the fact that chicken, fish, and eggs aren’t nearly as problematic as beef. In some future posts, I’ll try to ease the pain with practical tips. For now, though, let’s look at the data.
A recent study dug into the “food miles” debate with a more a comprehensive analysis of the climate impact of food production and transportation, based on the consumption of a typical U.S. household. The results were surprising: although food travels on average over 1,000 miles from farm to plate, this transportation accounts for only 4% of the carbon impact of the average American meal. In other words, even in the ideal scenario that you lived on a farm, you’d only be shaving 4% off your food footprint by eating locally — the rough equivalent of driving 1,000 miles less per year.
On the other hand, shifting just one day per week of red meat consumption to chicken, fish, or eggs achieves a reduction equivalent to 760 miles of driving. Shifting one day of red meat per week to fruits and veggies is the equivalent of 1,160 miles of driving. Swapping red meat entirely for other meats reduces the equivalent of 5,340 miles of driving. And going fully vegetarian is practically like giving up a car: 8,100 miles of driving. And when you think about it, this is good news for most of us. Cutting down food miles can actually be rather difficult. Cutting back on meat is fairly simple.
It’s worth unpacking the study a bit further. First, some perspective: local food devotees have motivations beyond just greenhouse gas emissions. There are plenty of good environmental, economic, social, and culinary reasons for favoring food grown nearby. Likewise, many considerations beyond climate change affect people’s personal decisions around meat consumption. Food can’t be reduced to a single issue.
And now some subtler considerations:
* The study considered the case of the average American household. If you’re reading this blog, there’s a good chance you’re not the average American household. You may already take steps to green your consumption choices, in which case the savings available to you from cutting meat consumption are smaller. Still, reducing your intake of beef and dairy is one of the simplest ways to shed CO2 from your diet.
* The study looks at aggregate food groups, which is entirely unhelpful if you’re trying to figure out how the organic raspberries from Chile compare to the conventionally grown peaches from California; or how the grass-fed, pasture-raised beef compares to that farmed salmon. Needless to say, there is considerable variation in production techniques within food groups. On the other hand, most of us aren’t cooking most of our meals, so the broad rules of thumb are still generally quite useful.
* Beef is even worse than the study makes it appear. The life cycle analysis doesn’t account for land use changes from beef production. A lot of rain forest gets chopped down to make way for cows.
* Consider skipping the soda. The beverage category isn’t a huge source of emissions, but I suspect it’s one of the easiest to cut. (And of course you’ve already given up the bottled water, right?)
* The study contains some unintentional weight-loss advice. Dairy (milk, butter, and cheese) is CO2-intensive and also quite energy dense. Shifting dollars into fruits and vegetables will cut not just carbon but calories from your diet.
* If you’re already a vegetarian, considerations such as food miles and organic farming techniques become proportionately more important. The absolute amount of carbon reductions available don’t change, but the relative importance of these factors increases.
* Globalization of the food supply doesn’t appear to be the big deal you might think, because trucking is so much worse, from an emissions perspective, than ocean shipping. (Planes, of course, are dreadful.)