Paul McCartney and his daughters aren't trying to make us all full-time vegetarians, though they themselves eschew meat.
"It's an environmental conversation, not a vegetarian one. It's ok to just give up meat for one day. It doesn't make you a vegetarian if you hate vegetarians. It doesn't make you a cranky, hemp wearing pot smoker. It's alright, it's allowed. It doesn't make you a kind of person you don't want to be. It just means you are doing something positive," Stella McCartney said in June when she and her dad and sister launched their Meatfree Mondays campaign.
Lowering our meat consumption will lower our carbon emissions - potentially having as much of an impact as if we all leave our cars at home and get on our bicycles to ride to work. On a personal basis we can cut our carbon in half with just three steps, one of which is weekday vegetarianism.
The McCartney's gentle approach - suggesting less meat instead of pushing no meat - may also have some sustainable agriculture benefits, supported by scientific research.
Cornell researchers looked at land requirements of the diets of New Yorkers and found that low-fat vegetarian diets took up the least amount of land, less than half an acre per person, while high meat and dairy diets required more than 2 acres.
Here's the interesting part, however. If a local, sustainable food production system is what we are aiming for, then a mixed diet may be the most efficient use of the land we've got. Fruits and vegetables need lots of high-quality cropland, while pastureland of lesser quality can be used to support grass-based farming.
"It appears that while meat increases land-use requirements, diets including modest amounts of meat can feed more people than some higher fat vegetarian diets," Christian Peters said in a report Cornell's research on Science Daily.
This basically echoes what sustainable agriculture advocates and small farm advocates have been saying for a while. Joel Salatin of Food Inc. is the most ardent of the grass farming advocates, but he is not alone.
And meanwhile, how much meat? For New York, Cornell's researchers actually established a number and it was 2oz. per person per day, or 14 oz. per week. Which makes meatless weekdays and occasional splurges seem like a very smart thing.
Read more about meat-free weekdays at TreeHugger and Planet Green
Green Food Matters
::Try a Weekday Vegetarian Diet: Eating Green Food Without Taking the Plunge
::How and Why to Eat Less Meat
Take if From a Beatle: Cut Your Carbon Footprint by Making Mondays Meat-Free
Climate-Friendly Cows Make Meat Eating a Little Less Bad
The Eco-Diet Isn't Just About Food Miles
Read more from Graham Hill on Huffington Post
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