Plant-Based Health Special Series: Does going vegan stack up for the environment?

By Matthew Stewart – BCom BAppSc [Human Bio] MOst PDC

2017 seemed to be a break out year for vegan diets. Many celebrities adopted vegan diets and news reports extolled plant-exclusive as the best way to avert the multi-faceted consequences of climate change. But is adopting a meat-free diet the best option to address environmental degradation including climate change?

Any discussion of the environment, sustainability, and climate change is overlapping and complex. Vital to the dialogue are the economics and energy costs involved for the current food production system and discussing future alternative methods to address our global predicament.  It’s also important to recognise that economics and energy are a subset of the environment and not the other way around.  Orthodox economics typically sees limitless growth in a finite system which is clearly madness given there are biological limits to growth in any system whether it be bacteria in a Petri dish or a herd of wildebeests on the African savannah.

First let’s look at the agricultural output and energy expenditure of ancestral populations. For every calorie of energy expended in producing food, hunter-gathers yielded 20 calories of food (1). There is an argument that population growth fuels intensification of production, which increases the risk for populations subsisting on these crops, which leads to new innovations which increased production. These changes allowed people to subsist with less labour and a more stable food supply with surplus to store and trade.  In this picture, technology is the hero and progress is always ‘good’.

However, this picture was challenged by the work of Danish agricultural economist Ester Boserup (2) who revealed that there was a diminishing return on labour with increasing intensification(3). In other words, with each additional unit of labour a smaller increase in production is achieved; workloads tend to rise while efficiency drops. This process is called agricultural intensification. It is true that this method produces more food than shifting cultivation but farmers have to work much harder. Why would a population shift to a system of agriculture with a steep cost in terms of labour and quality of life? Moving to a system of high production with less efficiency is driven by population growth or farmers compelled to by those in positions of power.

“Fertiliser is good for the father and bad for the sons.” – Dutch proverb 

Moving from a hunter-gather food production system to horticulturalism the yield decreases to 15 calories of food for every one calorie of work, and for intensive agriculturalists, four calories for every one calorie of work.  Modern mechanised farming systems such as used to grow corn in the American Midwest is even less efficient, using 10 calories for energy for every single calorie of food. Whereas energy in the hunter-gather systems come from human effort collecting stores of energy (plant or animal) that harnessed the photosynthetic activity of plants and from the recycling of biomass by the soil food web, the energy subsidisation of modern mechanised industrial farming comes from fossil carbon, debt, and government subsidies, either directly or indirectly.

The inefficiency of agricultural intensification is reflected by farmers’ incomes relative to their increased agricultural output since the advent of large-scale monoculture cropping of hybrid and GMO cultivars and heavy use of chemical fertilisers and pesticides. In Australia, wheat yield doubled in the 20 years from 1980-2000 however farmers’ profits halved during this period. In Canada, from 1926- 2016 gross farm production totalled $1.53 trillion.  Of that $1.53 trillion, $1.32 trillion went to input suppliers such farm machinery dealers, seeds suppliers, fertiliser sales, biocides and fuel. The average age of the dwindling number of Canadian farmers is 55, reliant on off-farm income, tax-payer supported tax schemes, debt (at record levels), and land sales (4). NZ agricultural production doubled between 1931and 19 57 and then doubled again between 1985 and 2005 but have farmers’ profits doubled and doubled again?

“The nation that destroys its soil destroys itself” – Franklin D. Roosevelt, 1937

Many innovations have propelled agricultural output to new highs but at increasing costs to the environment.  The development of the Haber-Bosch process in 1910’s Germany allowed the conversion of atmospheric nitrogen (N2) to ammonia (NH3) for the use in munitions in WW1 and afterwards in nitrate fertilisers as industrial military complexes developed during war time were repurposed for agricultural use to solve ‘the hunger problem’.  Nitrogen fertilisers have undoubtedly resulted in a massive increase in agricultural production. Canadian geographer Vaclav Smil calculated that were it not for the industrial fixation of nitrogen (5), the world’s population would probably not have exceeded 4 billion people — 3.6 billion fewer than are alive today. However, the Haber–Bosch process now consumes 5% of the world’s annual natural gas supply, with half of this resource squandered as nitrogen use efficiency is typically less than 50% with farm runoff causing significant disruption of biological habitats.

Prior to the early 20th century, the source of nitrogen in food consumed originated from animal manures, nitrogen fixing legume crops, and soil micro-organisms, since then the extensive use of synthetic nitrogen fertilisers has resulted in 50% of the protein and 80% of the nitrogen in our bodies having their origin in the fossil carbon fuelled Haber–Bosch process.  We literately eat fossil fuels. We are far from being able to replicate nature’s efficiency at converting some of the 78.1% of the atmosphere that is nitrogen to useful fertility, which is done by nitrogen-fixing bacteria (diazotrophs) at soil temperature, rather than at 450°C and 200 times atmospheric pressure in the Haber–Bosch process (6).

According to studies by the Millennium Institute, the world currently grows enough food for 10 billion people, 4600 calories for every man woman and child – twice as much as we need to thrive (7).  The issue is not a shortage of food but the location of food production and distribution, and post-retail waste. Hunger is caused by poverty and inequality, not scarcity.

What is remarkable is that the supply side of the agricultural equation is often discussed but the demand side is not. Population control is rarely mentioned in climate change and the overshoot of Earth’s carrying capacity. The median UN population estimate for 2050 predicts an additional 2.5 billion people, the emissions from whom would be the climate equivalent of adding two United States worth of carbon emissions to the planet.

Analysis by Brian O’Neill at University of Colorado, Boulder found that promoting family planning and small family norms would yield between 16 and 29 percent of what is necessary to avoid catastrophic climate change (8), yet this is never mentioned when discussing solutions to climate change.

In high-income countries such as the USA, United Kingdom and New Zealand, post-production – including storage and transport – contributes a large proportion of the food system’s greenhouse-gas emissions. A UN report reveals that people in developed countries throw away more than 30% of their food after they buy it.

So, will a swap to vegan food products change the unsustainability of the current food production system and its reliance of chemical fertilisers, pesticides and fossil carbon-powered mechanisation and transportation and food wastage outlined about? It is unlikely to be near enough to avert climate change and a transition to low carbon future.

The companies that are developing vegan meat substitutes are not addressing soil erosion, fossil fuel use, market skewing subsidies or carbon loss from soils due to tillage.  These venture-capital and multinational food processor-backed corporations are not marketing high-nutrient cultivars of carrots or high-protein cereals crops, rather they are racing to market with variations of ultra-processed nutrient-poor products based on cheap commodities such as grains, pulses, legumes, and vegetables or energy intensive cell-culturing (9).

This is reminiscent of the 1980’s and 90’s when some of the same corporations developed ultra-processed low-fat products from the same commodity products for the ‘heart-healthy’ and weight-loss market.

The current method of industrial agriculture in western developed countries is unsustainable. Most farmers and vegans would agree that meat production in confined animal feeding operations (CAFOs) is inhumane. But the problem is not the cow or the sow but the how; it is the current methods of agricultural production characterised by large-scale monoculture of pasture and crops, heavy use of chemical fertilisers and pesticides and GMO cultivars that lead to a loss of diversity, impoverished farmers, and massive soil erosion. About a third of the world’s soil – enough to feed 1.5 billion people – has already been degraded with 24 billion tonnes of fertile topsoil lost every year. New Zealand loses 192 million tonnes of soil to erosion every year with just under half of this loss from pasture and crop land (10,11). At the current rates of degradation, the UN’s Food and Agriculture Organization estimates the world has less than 60 years of topsoil left (12).

There are calls to make agriculture more sustainable. Sustainable agriculture has been described as ruining the land more slowly. What is required is restoration or regenerative agriculture.  Regenerative agriculture describes farming and grazing practices that, among other benefits, reverse climate change by rebuilding soil organic matter and restoring degraded soil biodiversity—resulting in both carbon drawdown and improving the water cycle. Small groups of farmers in Australia, USA, and New Zealand are implementing this approach with impressive results for their land and livelihood (see resources below).

We still operate out of a cultural meme that we humans are superior to everything else in nature, that we are big-brain mammals and can always come up with technology that is superior to anything nature does. New more sophisticated technology is prized and the more of it the better, no matter the cost. The criticism is that organic and regenerative methods are extolled by nostalgic Luddites and elitists who care only for those who can afford boutique produce. While this regenerative agriculture is reminiscent of the kind of agricultural practices of the past, what sets it apart is sophisticated knowledge and application of natural biological processes only recently revealed by modern science. A move to a high-knowledge, low technology, soil cherishing agriculture is required (13).

Those that stand to gain from this approach are the farmers and those who would directly benefit when farmers benefit; consumers. The entities that stand to lose revenues and profits are those that have ‘monetised Nature’ through the patenting of plant traits, pesticide resistant GMO cultivars, production of agro-chemicals, pesticides, herbicides, insecticides, fungicides and chemical fertilisers.

Consumers need a better understanding of the carbon cycle (14), water cycle and nitrogen cycle (15) to make more informed buying decisions rather than scare mongering marketing tactics of fake meat producers.

For more on Regenerative Agriculture

  • Call of the Reed Warbler: A New Agriculture – A New Earth, by Charles Massy (2017) University of Queensland Press.

Charles Massy writes on Australian farmers conversion to farming with the land rather than against it to restore the ecology, diversity, and profitability of their farms.

Nate Hagens PhD – Limits to Growth: Where We Are and What to Do About It


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  4. Standing Senate Committee on Agriculture and Forestry. Agriculture and Agri-Food Policy in Canada: Putting Farmers First! Senate Canada; 2006.
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