Lowering Our Carbon Foodprint

by Michael J. Caduto

In the mid-1970s, one of the seminal, transformative books read by millions worldwide was Frances Moore Lappé’s Diet for a Small Planet. Fast forward to Earth Day 2021 when Sustainable Woodstock and Pentangle Arts hosted Ms. Lappé for a live, virtually-broadcast talk during which she said she was originally inspired to write her book largely out of a concern that rampant population growth would outstrip the planet’s ability to feed humankind. Diet for a Small Planet revealed that growing grain for direct human consumption requires far less land than growing grain to feed cattle in order to produce meat. Therefore a plant-based diet would enable the world’s farmers to feed a vastly greater number of people. (Lappé’s Earth Day event was presented with support from Vermont Humanities and the Sierra Club Upper Valley Group.)

On average, livestock must consume 25 calories of plants in order to produce a single calorie of beef. The ratio for pork is 15-to-1, and for chickens it is 9-to-1. With nearly 8 billion people on Earth today, if the world adapted a plant-based diet, we could reduce the amount of land needed to feed everyone by 75%—from some 10 billion acres to 2.5 billion acres. If the farmland currently used to grow grain to feed beef cattle were instead used for poultry feed, the caloric and protein needs of an additional 120 to 140 million people could be met, based on the average U.S. diet. 

No one was focused on climate change in 1971 when Diet for a Small Planet was first published, at a point in time that just happened to coincide with when the rise in global temperature began to accelerate at an exponential rate. We eventually realized that, as the percentage of our diet that is derived directly from plants increases, our carbon “foodprint” drops proportionately. A person can reduce their carbon foodprint by 73% just by adopting a plant-based diet.

Of course, due to individual diet-related health needs, cultural and spiritual traditions and our strong rural desire to support local farmers, a completely plant-based diet it not always realistic. However, increasing the proportion of your diet that is plant-based will greatly reduce your carbon foodprint. For example, reducing the amount of red meat that you eat can quickly decrease your carbon foodprint by 25%.

A global shift to a more plant-based diet would also decrease the pressure to keep clearing more forest land for grazing animals and growing grain to feed livestock. This would in turn preserve forestlands, like those in the Amazon, that store and sequester vast quantities of carbon, thus acting as buffers against climate change. It would also enable the restoration of immense areas of habitat, slowing the disastrous loss of species that we are now experiencing in the midst of a human-caused Sixth Extinction.

Perhaps the biggest concern with the global effort to reduce carbon emissions generated by industry, households, transportation and agriculture isn’t whether we can eventually accomplish our carbon-reduction goals (the successful campaign to repair the hole in the ozone layer shows what we can accomplish on a global scale), it is whether we can do so in time to preserve some semblance of the world we know and love from the impacts of global warming. Installing solar arrays, erecting wind turbines, engineering more efficient and affordable electric vehicles and batteries, etc.—all take time, money and resources.

In the midst of this temporal dilemma in our critical fight against global warming, dietary change offers a realistic opportunity for individuals to significantly reduce their carbon emissions NOW simply by increasing the proportion of the diet that is based on consuming plants. This doesn’t mean that everyone will, or has to become vegan or vegetarian, but there are steps that everyone can take to lower their carbon foodprint:

  • Reduce consumption of meat and dairy.
  • Purchase meat and dairy from local and regional farms, rather than from sources that produce energy-intensive animal products that are raised on feedlots and transported hundreds or thousands of miles to reach the grocery store.
  • When consuming animal-based foods, choose those with the lowest carbon foodprint. For example: The production and transportation of locally-sourced, grass-fed meat and dairy generates a lower carbon foodprint than factory farming operations. Locally-sourced food travels shorter distances from farm to table, and buying locally supports regional farms and farm workers while investing in the local economy. Meat and eggs from locally-grown, free-range chickens and eggs have some of the lowest carbon foodprints of all animal products. One detailed study in the UK showed that the greenhouse gas emissions (GHGs) generated when producing eggs laid by free-range chickens (per kilogram of protein) is 625% less than the GHGs emitted when raising meat from chickens, and 3,250 times less than the GHGs emitted when raising meat from commercially-produced beef cattle. The carbon foodprint of milk protein was smallest of all, at just 1/5th the CO2 emissions of free-range chicken eggs.

Individuals, organizations, businesses and governments throughout the world are working hard to design and build new infrastructure and energy systems that will reduce carbon emissions for the long-term. But every one of us has the ability to make basic dietary choices today that can significantly accelerate our response to climate change by drastically reducing our carbon foodprints.

The carbon foodprint of protein derived from eggs laid by locally-raised free-range chickens is 3,250 times smaller than that of commercially-produced beef. Photo credit: Michael J. Caduto


  • Read Frances Moore Lappé’s Diet for a Small Planet, and Anna Lappé’s Diet for a Warm Planet. (Please support your local bookstore!)
  • Pick up some of the excellent cookbooks that are full of recipes that offer no end of delicious plant-based meals, such as Moosewood Cookbook by Mollie Katzen, Sweet Potato Soul by Jenné Claiborne, The Vegetarian Epicure by Anna Thomas and The New Vegetarian Cooking for Everyone by Deborah Madison.


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