Diet for a Cool Planet – Part Two

    If you missed Part One, you can read it here.

    Do a quick web search for “sustainable diet” or “climate friendly diet” or even the title of this essay, and you’ll get a slew of articles talking about little else but the need to eat less meat, particularly on Mondays. This is pretty much the only climate-friendly eating advice we’ve been given in recent years. And it’s certainly true that there are huge environmental, animal welfare, and human health problems associated with our industrial meat production system, and that if this were our only option, we should all be vegan. Yet hardly anyone seems to acknowledge that there is more than one way to raise an animal, and that there are ways to do so that are far less harmful than the industrial model that is so rightly criticized.

    When I first started learning about agriculture, I approached it from a permaculture perspective. And in permaculture, the cow is a real hero. She is the alchemist who, through the magic of her four stomachs, can turn the Earth’s vast stretches of inedible (to us) grass into rich butter, cream, milk, and meat. And her dung is an elixir to gardens everywhere. No wonder she is holy in India.

    Permaculturalists also see eye to eye with holistic management, a livestock grazing system developed by Allan Savory in the 1960’s in Africa. In this system, now employed on over 13 million hectares globally, cattle are the saviors of the climate and biodiversity. By intensively grazing ruminants in small paddocks and moving them often, mimicking the natural movements of wild herds constantly evading predators, they stimulate grass productivity and carbon sequestration in the soil. According to the UNCTAD, “pastoral livestock systems can even be carbon neutral.”[1]

    There are even methanotrophic microorganisms in healthy pasture soil that have evolved to metabolize some of the methane emitted by grazing herbivores; this is a frontier in soil science that is not yet well understood, but it is never accounted for in calculations that condemn all cattle as climate pariahs.  Grass and ruminants have coevolved for 90 million years, over a soil biome much older than even that, and they all fit together in an intricate balance we are only beginning to discern.

    So I was surprised when, after the FAO’s publication of Livestock’s Long Shadow in 2006,[2] the media and scientific community started piling on to the cow as public enemy number one to a stable climate. Those animals that eat grain – like chickens and pigs – were supposed to be better choices than the economical cow, or her ruminant cousins, sheep and goats. Yet permaculture has a low opinion of grains, being annual crops requiring regular tillage. All I had learned was turned on its head.

    How could this be? The answer is simple: methane. The same miracle of the ruminant’s gut microbiome that allows it to transmute rough grasses into some of the most nutritious and delicious foods on the planet also produces the infamous 28-times-more-warming-than-CO2 methane belches that push us closer to the climate brink. Fully half of the 24% of emissions caused by farming mentioned in the Nature Food study in Part One are coming from methane – so 12% of global anthropogenic GHG. And while some of that is from rice cultivation and compost, the lion’s share is from enteric fermentation: cows’ guts.

    But wait – methane may be more potent, but it’s also way less persistent than CO2. A molecule of methane only hangs around in the atmosphere for about 10 years, whereas CO2 will linger for centuries. So while all the CO2 emitted since the Industrial Revolution is still building up in the air, the methane burped a decade ago is already gone. The atmospheric methane sink has a large drain in its bottom, constantly emptying, while the CO2 sink drains at a slow trickle.

    What all this means is that if the global herd of cattle don’t increase in number, then they don’t cause an increase in global warming. The methane they produce is constantly being lost at more or less the same rate that it’s being produced. Unlike CO2, which ratchets up with each kilogram of carbon combusted, and will continue to trap heat on our planet for centuries after we burn our last tank of gas, methane concentrations adjust relative to current emissions.[3]

    It’s this aspect of methane that a new metric, known as GWP*, attempts to account for. Developed by a team of scientists based at the University of Oxford, including Professor Myles Allen, a contributing author of several Intergovernmental Panel on Climate Change (IPCC) reports, it seeks to replace the old metric, known as GWP100. GWP stands for Global Warming Potential, and the 100 means over the next 100 years. But this new metric aims to provide a much more accurate prediction of the actual warming potential of methane. Under this new calculation, the impact of methane released from cattle and sheep operations is typically reduced by 50% to 75%. Many farming organizations in the UK and New Zealand have signed on to a letter asking the IPCC and governments to switch to this new way of measuring the climate impact of methane.

    So what if we reduced the 100 million strong North American cattle herd – would methane levels go down? Not if we didn’t exterminate all the wild ruminants that would seek to take their place. The pre-Columbus bison population is estimated to have been around 60 million. All those bison, plus an estimated 100 million small antelope, were emitting methane just like the cattle that European settlers replaced them with.[4] Were North American indigenous peoples responsible for climate change because they ate bison? Enteric fermentation – the process ruminants use to break down grasses – is a natural process that has been functioning on our planet for millions of years without triggering climate change. We have come along recently and replaced a whole lot of wild ruminants with domesticated ruminants, but in absolute terms I doubt we have managed to increase the global herd by much.[5] While the slaughter of bison and other wild ruminants is nothing to be proud of, should we not count it as a negative anthropogenic GHG emission if we are counting the emissions from livestock as a positive?

    Livestock living large

    A final knock against the cow I’ll seek to address is that she takes up far too much land. And it’s true: on a unit of food per hectare basis, livestock are far less efficient than plants at producing calories and protein. But a pasture it not a cultivated field. About one third of the world’s terrestrial area is natural grassland, and as much as 70% of farmland can only be grazed by ruminants (it’s too hilly, rocky, hot, cold, or arid for crops). Ruminants move through these pastures intermittently, with long rest periods in between. These lands are natural ecosystems with a full range of animal life occupying every niche, from gophers burrowing underground, to hawks patrolling the skies. If haying is done, it can be delayed several weeks to allow for threatened birds like the bobolink to nest and fledge. Compare this to a monoculture of corn or soy: sprayed with pesticides, it is a wasteland for every lifeform other than the one target crop. Livestock may take up more land, but they share it.

    Livestock are a problem when they are responsible for deforestation. Forests are one of the best carbon sinks we have, and we need more of them, not less. But often the forests we hear about in the tropics getting felled to make way for livestock are only being grazed for a year or two, then turned over to growing soybeans or other commodity crops. And, yes, the majority of those soybeans are destined for livestock feed, but we shouldn’t be feeding ruminants grains and legumes. We should only be consuming 100% grassfed beef and lamb. So grassfed beef shouldn’t be blamed for tropical deforestation.

    Ideally we would only eat ruminants raised on natural grasslands – those areas too dry to support the growth of trees. But I do live in a part of the world that wants to be a forest – a field left unmowed for a few years quickly starts sprouting pioneer tree species – and yet the flatter parts were cleared by European settlers in the 1800’s to make farms. As people moved to the cities and found other ways to make a living, some of the more marginal farmland reverted to forest.[6] In my hilly area, the fields that remain are still too small, irregular and undulating to justify the scale of modern field cropping, so most of them are just hayed once a year to feed a small number of beef cattle or sheep. It is not an efficient use of land, and from a carbon perspective it would be better if these fields were allowed to go back to forests, and the livestock sent west. However, there are some eastern ranchers who are employing the lessons from holistic grazing, increasing the productivity of their herds, while sequestering carbon in their soils. And there is real value in eastern consumers being able to know and buy directly from the people who produce their meat, rather than purchasing anonymous prairie steaks, to say nothing of the CO2 created trucking meat eastward. Nevertheless, there is a legacy deforestation in my part of the world, which is no less damaging to the climate than the current deforestation underway in the tropics, and we should be thinking carefully about whether the benefits of our local cleared landscapes justify their costs.

    The fundamental problem with the whole cattle-are-bad-for-the-climate argument is that it takes a completely natural ecosystem function – human animals eating other animals, who happen to emit methane – and conflates it with a wholly unnatural industrial process: humans pumping hydrocarbons out of the earth and burning them, releasing millions of years of stored CO2 in a blink of geological time. It is this sudden burst of combusted carbon that the Earth system can’t handle; it has been managing enteric fermentation just fine for eons.

    While methane is the main GHG created by livestock, they are also responsible for some nitrous oxide and carbon dioxide emissions. These are created by growing and processing feed, manure management, and transportation. This again points to the desirability of eating animals who have only eaten grass, taking feed production out of the equation. And concentrating large numbers of animals in small areas inevitably leads to problems of manure management; when water is used to flush manure away and then stored in lagoons, anaerobic bacteria go to work and create methane as a by-product. A full 10% of Canadian agricultural emissions stem from manure.[7] The solution is to keep livestock dispersed over the landscape, adding their manure in healthy doses that the land can absorb and use to fertilize plants. As a report from the UNCTAD put it, “An optimal combination of crop farming and animal husbandry produces the most efficient nutrient cycles,”[8] which is another benefit to having local livestock production, even in areas that would naturally be a forest.

    The above flies in the face of the commonly accepted thinking that condemns all livestock as climate criminals. It argues that we need to think about methane differently from CO2, that we should think about biologic animals’ stomachs as distinct from internal combustion engines, and that livestock’s impact on the landscape is not the same as plant crops. We should also be drawing clear distinctions between thousands of cattle crammed into a feedlot, finished on artificially fertilized and pesticide sprayed GMO corn and soy, and 100% grass-fed animals being rotationally grazed on natural pastures, with their manure being turned into high-value compost that nourishes the vegetable crops we need and love to eat. Grain finished beef uses twice the energy as grassfed beef, because of the energy to fertilize and transport the grain, and to transport the livestock to the feedlot.[9]

    I am not alone in making this argument; there are many environmentally-minded people working in regenerative agriculture, permaculture, and academia who would agree that regeneratively raised livestock have been unfairly vilified and tarred by the same brush as industrially raised animals.[10] As these people like to say, it’s not the cow, it’s the how.

    Just one example of this is a 2019 study commissioned by White Oaks Pastures, a family farm in Georgia, USA, that looked at the “carbon foodprint” of the beef they produce. They found that for each pound of beef they produced, 3.5 pounds of carbon were sequestered in the soil, thanks to the rotational grazing of their cattle. Their cows were storing more CO2 equivalent in the soil they grazed on than they emitted during their lives.[11] There are many other examples.

    As for pigs and chickens, to whom we feed grain, and dairy cows, who eat grass but also must eat some grain to produce the amount of milk we’ve bred them to, I see them as less climate-friendly, because it is harder to sequester carbon in soil that is being tilled regularly to grow grain. However, if the grain is being grown organically, there is a greater chance that carbon is being sequestered. Add to this the fact that it is also grown without the GHG emissions of artificial fertilizer. [12]

    Seafood is a whole other story, and beyond the scope of this essay. Let me just say that personally, I feel pretty good about eating shellfish – they don’t require any feed, and they actually clean the water they live in. Check out or former Newfoundland fisherman Bren Smith’s book Eat Like a Fish: My Adventures Farming the Ocean to Fight Climate Change for an inspiring new model of ocean farming seaweeds and shellfish regeneratively.


    A Diet for a Cool Planet, in 9 Recommendations

    A caveat: I recognize that the recommendations below usually require more time to source and money to buy, and so are not available to everyone. You need to have the resources to shop at farmers’ markets, health food stores, or buy directly from producers. I do believe that many more of us in high income countries could take advantage of these options than currently do. But on behalf of those of us who can’t, we should all be pressuring governments to make quality, healthy, and environmentally sustainable food a basic right that everyone can afford.


    1. Buy organic

    At its best, the organic label means the farmers who grew it applied to all aspects of their operation the concept of working-with-nature that is foundational to shifting agriculture from a GHG emitter to a GHG sink. At its worst, certified organic producers are still applying an inputs-based industrial model to growing food, treating the soil like a sterile medium to hold their plants up in. But at least they still can’t use highly damaging synthetic nitrogen fertilizers. So buy organic whenever you can.


    1. Know thy farmer

    Beyond the organic label, there’s not a lot of information a consumer can glean at the grocery store about how a product was grown. There is no (wide-spread, at least) regenerative label yet. To find out how much a farmer is tilling, or how much they use cover crops, or how many trees or wetlands they conserve on their farms, or how they heat their greenhouses, you’re going to have to exit the grocery store aisles and do a little digging online and at your local farmers’ market. But please, be considerate; most farmers are working really hard, doing the best they can with the resources available to them, and customers asking loaded questions about farming practices can easily get our backs up. Just express a genuine interest in how things are produced, buy at least something to thank them for their time, and then let your wallet express your judgement next time you visit the market.


    1. Consider eating more perennials (and don’t sweat the food miles)

    I’m hugely in favour of getting to know your local farmers (see #2), but there are many great perennial foods that can’t be grown anywhere near Canada, and we shouldn’t worry too much about the carbon foodprint of these delicacies. Boats are very efficient.


    1. The last food mile might be the worst

    Boats may be efficient, but using an SUV to pick up a carton of milk isn’t. This is where there is a potential conflict between #2 above and #4; spending a morning visiting a farmers’ market, a small retailer, and a farmstand can easily use much more gas than loading up the car at Costco. One solution is to sign up for a Community Supported Agriculture (CSA) share or other foodbox program that can be delivered directly to your house or to a nearby drop-off point; it is much more efficient for one vehicle to drive around making deliveries than for 50 customers to all hop in their cars and drive to the farm. Since the beginning of the pandemic, there are also a lot more local farms offering online stores and home delivery. If you prefer shopping in person, consider walking, using a bike, or taking public transit. Try to think ahead about grocery needs and do your shopping on your way home from work. If you do want to drive out to the country to visit a farm store, offer to pick up some stuff for your neighbours, or make a day of it and visit several at once – many regions have agrotouristic routes promoted by local organizations (in the Outaouais you can find them at


    1. When it comes time to replace home appliances, get the most efficient you can

    Our stoves and fridges can suck a lot of energy, so try to get the highest Energy Star rated ones you can afford. Also consider if the brand is known for its longevity, as a lot of energy is consumed in manufacturing.


    1. Send food packaging packing

    Some packaging will always be necessary, but we can certainly reduce it, by buying more raw ingredients and cooking ourselves, rather than prepared foods, or by frequenting one of the growing number of zero waste stores, where you bring your own reusable packaging. If you can’t reduce, try to at least choose recyclable or compostable packaging.


    1. Waste not, warm not

    Treat food as sacred. Wasting it is an affront to the life given by the plants and animals you eat. Keep on top of leftovers and best before dates. Repurpose bones and vegetable scraps into nutritious soup stocks. Cook what is in your fridge, not your cookbooks. If you have to throw food out, compost it (vermicomposting is accessible to even apartment dwellers, and more and more municipalities are introducing regional collection and composting).


    1. Eat animal products if you want to, but source them well

    At a minimum, beef and lamb should be rotationally grazed, and fed a 100% grass diet. If they hail from natural grasslands, or were raised using “silvopasture” – pastures mixed with trees, which can sequester up to three times as much carbon as regular pastures – then even better. Animals that can’t eat much grass, like pigs and chickens, should be fed organic grains, although even these non-ruminants benefit from living on pasture – they will eat some grass, and be much happier and healthier out in the open. So always look for pastured eggs, for instance, if you want the yellowiest yolks. Because of dairy supply management in Canada, where most milk is consolidated in centralized tanks before being distributed, it’s rare to be able to source milk or other dairy products directly from a farm and know their production practices.[13] In this case, the best you can do is to buy organic.


    1. See food as the solution, not the problem

    We spend so much time staring a screens now, most of us feel lucky to be able to get out into nature once and a while. Yet every day you put nature into your mouth. Despite our best efforts to synthesize, industrialize, process, and package the nature out of the food we eat,[14] it is still bits of life grown by natural processes that we consume, and as such it is our most intimate and regular interaction with the natural world. Use each meal as a time to connect with the natural world around you, and to deepen your understanding of the interdependency of all life on this planetary oasis we find ourselves on. Loving food can be a gateway drug to loving nature. Food allows us to put the “sustenance” back into sustainability. The Earth sustains us, and climate change is just one manifestation of us having forgotten this. Let food be your daily reminder.


    [1] Wake Up Before It Is Too Late: Make Agriculture Truly Sustainable Now for Food Security in a Changing Climate, UNCTAD

    [2] The report made the startling claim that, at 18%, livestock’s share of human GHG emissions was larger than the entire transportation sector. Later it was pointed out that, while the report’s authors included a whole life-cycle analysis of livestock emissions in their calculations, they only counted tailpipe emissions for vehicles. The FAO then lowered their estimate to 14.5%.

    [3] Atmospheric methane concentrations have increased 2.5 times from pre-industrial levels, but the fossil fuel industry also emits a lot of methane. It was recently reported that natural gas may be almost as bad as coal, once you factor in all the small leaks in piping infrastructure. Natural gas is primarily methane, after all.

    [4] They were also building some of the deepest, richest soils in the world.

    [5] Perhaps artificial fertilizers have allowed us to grow more feed and thus increase the worldwide ruminant herb somewhat above natural levels. Just another reason to get off artificial fertilizers and feeding cattle grain.

    [6] However, this forest regeneration peaked in New England in the late 20th century, and a second wave of deforestation driven by urban development is now underway.

    [7] Tackling GHG Emissions from Livestock Production, National Farmers’ Union

    [8] Wake Up Before It Is Too Late: Make Agriculture Truly Sustainable Now for Food Security in a Changing Climate, UNCTAD

    [9] A Carbon-Friendly Beef Enterprise – Is It Possible?, Christine Jones, PhD,

    [10] Check out Meat: A Benign Extravagance, by Simon Fairlie.


    [12] In a perfect world, we would feed these animals all our waste food, which is about a third of what we grow. This is what farmers used to do, before grain got so cheap. Maybe we can get back to that again someday.

    [13] In my region, the only farm I am aware of that you can buy directly from is Biemond (, an hour south of Ottawa.

    [14] The drive for lab-grown meat is just the latest attempt at this.

    3 thoughts on “Diet for a Cool Planet – Part Two”

    1. Pingback: Diet for a Cool Planet – Part One - Sean Butler

    2. Hey Sean — as per our discussion on email about prehistoric animal abundance…
      So there was one topic that you mentioned that I looked into a few months ago, as it had tickled my curiosity. The question that I had asked myself was, “Exactly how abundant were all of the wild animals before humanity went and changed everything?” — Those buffalo herds on the plains that you mention being a prime example. I’ll just give you a very brief overview of what I found and a couple of sources.

      -Total mammal biomass today is 8x more than in prehistory, from 20 million tons carbon 100,000 years ago to 160 million today
      -Wild mammals are down by 85% since prehistory, from 20 million tC to 3 million tC
      -Humans and livestock now make up 98% of terrestrial mammal biomass.

      So we have far more cows and livestock today than the prehistoric North America ever had in wild animals. I think that this all comes down to efficiency of land use and covering up the seasonal ‘gaps’ in food that wild populations must deal with.
      -Fields are now optimized for cattle forage production vs. a natural ecosystem where all the parts are selected (via natural selection) for being able to outcompete other species that would invade and replace them.
      -Deer populations in the Gatineau Hills are constrained by food availability in late winter, while cows are not.

      Sources of info:

    3. Hi Sean – I really appreciate you wrangling all of this and setting it down in a way that I too can almost get my head around. I also love the comments you made in #9 – seeing food as the solution and not the problem.

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