Adapting to climate change: the vegan answer to declining agricultural yields

Rob Baylis, MSc, MIEMA, CEnv
July 2020

The decade between 2020 and 2030 is probably the most important in the history of humanity.

There is a choice to be made between two alternative futures.  The first is to treat the Climate Emergency with the same level of urgency as the Covid-19 pandemic by cutting emissions of greenhouse gases sufficiently to limit global average temperature rise to 1.5 degrees Centigrade above what it was before the industrial revolution. In doing this, the quality of everyone’s lives will be much improved through better jobs, lifestyles and health along with reduced air pollution, more natural open spaces, more comfortable homes and less scope for conflict.  This will be especially important for the most vulnerable people in societies across the globe who will otherwise suffer the increasingly unequal and unjust impacts of climate change.

Scientific analysis channelled through the Intergovernmental Panel on Climate Change (IPCC) tells us that this choice will necessitate a reduction of global greenhouse gas emissions to net zero by 2050[1].  To achieve this, the level of emissions in 2020 will have to be cut by 50% by 2030, halved again by 2040 and the remainder eliminated in the following decade[2].  ‘Net zero’ will mean that any unavoidable emissions will have to be absorbed by carbon ‘sinks’ such as through restoring forests.

The second choice is to take inadequate, token or no action to limit greenhouse gas emissions, or even to grow them as is happening now with increases in consumption of animal products in some parts of the world, Amazon deforestation, Australian investments in coal mining, enlarging airports and the G20 nations (including the USA & UK) providing £95.5bn of unconditional support for fossil fuel firms between March and July 2020[3].   This business as usual choice will trigger irreversible climate changes (tipping points).  It is currently projected to deliver a disastrous global average temperature of over 4 degrees Centigrade by 2050[4].

Regardless of which path is chosen to the future, humanity will be forced to adapt to the changes in climate that are already with us now and those that are on their way as a result of historic emissions and the remaining ‘carbon budget’ that cannot be exceeded if global average temperature rise is to be no more than 1.5 °C above what it was before industrialisation.  Climate change is the cause of slow but already unstoppable rises in sea levels, retreating glaciers, more erratic monsoons and increasingly severe storms and heat waves.  The more frequent and intense instances of flooding in Calderdale must surely be local manifestations of climate change and the very heavy downpours it brings.  

Adaptation to the consequences of climate change is rarely mentioned in the mainstream media other than in the context of flooding.  One example of this media vacuum was a landmark report published in September 2019 by the Global Commission on Adaptation.  That report, Adapt now: A global call for leadership on climate resilience[5] indicates, amongst other things, that food insecurity is worsening because of more intense and frequent droughts and floods.  These impacts will be accompanied by a greater prevalence of pests, parasites and disease thereby reducing the productivity of land further.  

The Adapt Now report contains a very chilling forecast that agricultural yields could decline by as much as 30% by 2050 if ambitious action is not taken to limit climate change[6].  This would be linked to global demand for food increasing by 50% and prices rising by 20% for billions of low-income people.  At the same time, the report posits a 70% or higher growth in consumption of animal products.

To accept growth in the consumption of animal products without question or without proposing action would seem to be misguided but that is what the ‘expert’ authors of the Adapt Now report do.  Their proposals for adapting to declining agricultural yields are confined to that age-old substitute for action – more research – along with ‘digital advisory services for small-scale food producers’ and ‘expanded access to and use of adaptive technologies and agroecological practices’ that support ‘climate-resilient crops, fish and livestock’.  Or simply, tiptoeing around the edges of the symptoms rather than tackling the root cause of the problem.

Whilst it is laudable to focus on small-scale food producers and co-operatives, especially those in the less privileged parts of the world that will suffer disproportionately from the impacts of climate change, the Adapt Now report proposes no actions to reform large-scale food production.

Meat and dairy consumption accounts for at least 14.5% of worldwide carbon emissions[7] and so there is already a compelling case, on climate change grounds as well as health, ethical and other reasons, for a widespread switch to a vegan/plant-based diet.  However, animal products also account for 83% of agricultural land-use whilst serving only 37% of protein and 18% of calorie consumption[8].  Therefore, vegan/plant-based diets must be a solution to food insecurity and discriminatory injustice associated with the projected decline in agricultural productivity.

The IPCC’s Climate Change and Land report, published in 2019[9], did attract media attention because it was brave enough to address animal-based agriculture. It argued that ‘dietary changes could free several million km2 (medium confidence) of land’ by 2050.  Others have estimated that a global shift from animal to plant-based foods would reduce agricultural land-use by 76%, and water pollution by 49% compared with 2010 levels[10].

Recommendations to cut consumption of animal products are regarded by the media and politicians as contentious because people would need to change their addictions and habits to make the reduction happen.  Governments, particularly right-of-centre governments, are keen to avoid what they see as limiting personal freedoms[11].  Despite dietary change being a low-cost tool for tackling climate change, another key reason for institutional resistance to it  is the noisy and misleading objections from animal-agriculture’s vested interest groups and lobbyists.  Moreover in the UK, for example,  parliament is well known for being dominated by MPs with animal agriculture interests. In a future article, I will return to analysing the validity or otherwise of arguments by vested interest groups but dietary change has to be taken seriously if humanity is to adapt to a 30% decline in agricultural productivity.

Logically, there has to be two ways to make this adaptation.  Either, use more land for producing food, or eliminate inefficiencies in the production and use of food.  Given that the availability of land for agriculture is limited and there is much inefficiency in the use of existing agricultural land, it makes sense to tackle inefficiency as a priority. 

There are various aspects of inefficiency in food production.  One aspect is the estimated 9.5 million tonnes of food wasted in the UK every year[12].  Out of this, 380,000 tonnes of meat is wasted with a  value of £3 billion according to a  meat industry initiative Meat in a Net Zero World[13].  There is room for optimism here since both the public and private sector In the UK agree that food waste should be cut dramatically.

Not surprisingly, Meat in a Net Zero World fails to address the fundamental inefficiency inherent in meat (and other animal-derived foods).  Animals exploited for human food spend their lives converting plants into flesh, eggs and milks at the same time as releasing greenhouse gases, defecating, urinating and converting food into energy.  In contrast, vegans eat plants directly.  The result of this is that the mean area of land required to produce beef is 164m2 per nutritional unit compared with 3.4m2 for peas[14].  That’s 48 times more land for beef than needed to grow peas to provide the same level of nutrition. 

Part of the reason for the huge disparity in land requirements is the large areas dedicated to growing animal feed instead of food for direct human consumption.  Changing to a vegan/plant-based diet will therefore be crucial in liberating the land necessary to cope with the forecast drop in agricultural productivity if cuts to greenhouse gas emissions are not enough to limit global average temperature rises to 1.5 degrees Centigrade.   It will also release land for restoring natural vegetation, such as forests, to remove carbon dioxide from the atmosphere.


[2] J. Falk, O. Gaffney, A. K. Bhowmik, P. Bergmark, V. Galaz, N. Gaskell, S. Henningsson, M. Höjer, L. Jacobson, K. Jónás, T. Kåberger, D. Klingenfeld, J. Lenhart, B. Loken, D. Lundén, J. Malmodin, T. Malmqvist, V. Olausson, I. Otto, A. Pearce, E. Pihl, T. Shalit, Exponential Roadmap 1.5.1. Future Earth. Sweden. (January 2020.)


[4] Interpolated from


[6] This is in addition to forecasts that the UK has less than 40 years of fertility left in its agricultural soils due to intensive farming.


[8] Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360, 987–992


[10] Poore & Nemecek, op. cit.



[13] WRAP, 2020, Banbury, Meat in a Net Zero world

[14] Poore & Nemecek, op. cit.

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