The WorldWatch Institute have published the first in a two-part series examining the potential environmental and economic impact of greater localization of food. And, as always, they've put together an interesting read for the current issue of WorldWatch Magazine. One that summarises the local food movement, including Food Miles, 100 Mile Diets and Locavores. Then they unearth a bunch of farming and transport studies and poke into their findings. After which they pull back a bit, so they can see the paddock from the peas.
We suggest you read the full article. But some of the juicy titbits are noted below.The Leopold Center for Sustainable Agriculture famously found that US food travelled an average of 1,518 miles (about 2,400 kilometers) from gate to plate. Yet looking at local markets, such as Iowa, they concluded locally sourced food travelled an average of just 44.6 miles (72 kilometers). They calculated that the" conventional food distribution system used 4 to 17 times more fuel and emitted 5 to 17 times more CO2 than the local and regional (the latter of which roughly meant Iowa-wide) systems."
Similar studies in Canada and Sweden came to much the same conclusions.
Something About Dairy
What you eat matters at least as much as how far it travels. One study by Carnegie Mellon University researchers observed that:
"No matter how it is measured, on average red meat is more GHG [Greenhouse Gas]-intensive than all other forms of food," responsible for about 150 percent more emissions than chicken or fish. In their study the second-largest contributor to emissions was the dairy industry."
Meat and dairy contribute 58% of the total food emissions from a typical Swedish diet. And globally livestock account for 18% of all greenhouse gas emissions-more even than all forms of fossil fuel-based transport combined.
Referencing again the Carnegie researchers:
Replacing red meat and dairy with vegetables one day a week would be like driving 1,160 miles less. "Thus," they write, "we suggest that dietary shift can be a more effective means of lowering an average household's food-related climate footprint than 'buying local.'"
Food Miles Not the Whole Story
But as Rich Pirog author of the USA study said, "food miles/kilometers don't tell the whole story. "Food miles are a good measure of how far food has traveled. But they're not a very good measure of the food's environmental impact."
Many other variables enter the equation like transport mode and cultivation methods. Potatoes trucked in from 100 miles away have the same greenhouse gas emissions as spuds shipped by rail from 1,000 miles away. Swedish shoppers would be greener buying Spanish tomatoes grown in open fields, than local Swedish grown in fossil-fuel-heated greenhouses. That is until a climate change induced drought forced Spanish growers to use water intensive irrigation.
Organic vs Local
They discuss the benefits of organic food production: often lower greenhouse gas emissions because no fossil fuel synthetic fertilizers and pesticides are used. Other pluses include: greater farmland biodiversity, less irrigation, diversity of crops, native biodiversity, and integrating crop and livestock production. Here again they cite Christopher Weber of Carnegie Mellon University saying,
"the production practices matter a lot more than where the food was actually grown. If buying local also means buying with better production practices then that's great, that's going to make a huge difference."
But they do acknowledge that while the local farmer may not be growing organic, at least the customer has the opportunity to engage directly with him/her and help build up trust such that the farmer may implement more environmentally benign farming practices.
They like Michael Pollan's mantra of: "Eat food. Not too much. Mostly plants," going on to suggest: You could sum up the ecological case for eating locally by adding one more sentence: "Mostly what's in season and grown not too far away."
But ultimately they believe there are limits to localised food. Observing that, "Large concentrations of people live in areas not suited to growing certain staple crops," pointing out that "... population density itself works against relocalization of the food system." WorldWatch's possible solutions include greater investment in rail infrastructure helped to reverse the trend toward transporting more food by inefficient semi-truck? And a carbon-pricing system incorporated some of the environmental costs of agriculture that are currently externalized?
Sarah DeWeerdt has written a great piece, adroitly encapsulating the many issues confronting our food system. Read it.
Photo credit: Flickr and WorldWatch