Scotland’s future food production: Turning CO2 to carbohydrates

Ian Boyd argues for employing manufacturing principles to convert CO₂ into carbohydrates (sugars), enabling the production of proteins and oils for food systems. Scotland imports almost half of the food it consumes. Much of the calories in Scottish farm production are used for alcohol production or livestock feed, according to government statistics. Since Scotland uses little of its agricultural land to grow food for people—what can be done to improve the security of food production in Scotland?

The challenge

The next few decades present many challenges for humankind but one of the greatest of these is to find a way of supplying sufficient, healthy food to people while not degrading the environment to the extent that human health and welfare also become degraded¹. This is a trade-off between benefits and costs within the current food supply system².

Current indicators involving: biodiversity loss³; reductions in soil nutrients⁴; aquatic eutrophication⁵; unresolvable emissions of greenhouse gases⁶; declines in innovative ways of increasing food yield⁷; and the increasing frequency and impact of non-communicable disease caused at least in part by poor diets^8,9, point to a food system which is under stress. Expressed in terms of system dynamics, the food system is a long way from an equilibrium state¹⁰, meaning that at present inputs in the form of materials and energy are not sustainable through time. This should be concerning because food system failure would result in mass starvation and collapse of current political and economic norms.

Scotland is vulnerable to these effects partly because it is intimately linked into the global food system and because its “food” supply capabilities are, in general, not deployed to supply food at all. For example, according to Scottish Government figures, Scotland imports about 46% of the food it consumes (including vegetables and important commodities like wheat flour) and only 21% of calories produced in Scotland are for human consumption. Most of the calories produced in Scotland are used to make alcohol or are fed to livestock. Even if livestock are eventually used for food, use of food in this way can incur up to a 90% loss of food chain efficiency [a], thus exacerbating reliance on imported food. This implies that not only does Scotland export a large amount of its food production, much of the environmental impacts of food consumption by Scottish people are beyond its borders. Overall, Scotland uses relatively little of its suitable agricultural land to grow food which supports people.

The situation in Scotland has arisen because market processes drive economic rather than energy or nutritional efficiencies and are largely insensitive to strategic issues of food security. The food system is geared to making money rather than feeding people or the need create resilient supply chains.

Two general approaches are usually considered to deal with these kinds of problems¹¹. The most popular involves reform of the food production system. This can emphasise, for example: a more directed food policy involving better assignment of land to various functional uses, one of which is food production; reducing food support subsidies (mainly delivered through support payments to farmers and tax breaks on fuel); or incentivising production of specific kinds of foods like fruit and vegetables. However, experience of national-level policies towards food production have shown that they can introduce many negatives such as over- and under-production. In addition, it is very difficult for a small producer nation like Scotland to act on its own when its food economy is intimately linked to the global food economy. Even when policy is enacted at the level of the EU, food production policy has been enormously difficult to shift. Many attempts have resulted in ignominious failure, exemplified by “butter mountains” or “milk lakes” and the general failure of environmental measures within the Common Agricultural Policy to reverse, or even to stop, declines in biodiversity.

The second general approach has been to invest in research and technology development, in the hope that innovation can resolve the problem. Sometimes this is called sustainable intensification⁵, but there is a lot of evidence that the returns on investments in agricultural research are nowhere near sufficient to address the rising yield gap⁷ let alone the need to reduce the creeping, incremental use and degradation of land to support food production.

Meeting the challenges of food production has, therefore, proved to be problematic both for policy and technical innovation. Failed attempts at reform of the EU Common Agricultural Policy have demonstrated that there are very strong forces which tend to stabilise the food production system in its current form and which work to prevent reform. These happen largely because agricultural policy is a mixture of economic, environmental, and social policy but where social policy designed to keep farmers on the land (especially involving incentivising farmers to sustain outdated modes of production) gets the lion’s share of political attention. Both economic and environmental objectives for farming are consistently subdued because of the dominance of the political leverage held by farmers. In the language of system science, there are very strong stabilising feedbacks which defeat even the most determined reform agendas.

In these circumstances, what are the options available to satisfy the need for increased food production and to achieve this in ways which would alleviate further environmental degradation and to achieve this in ways which are politically feasible by keeping farmers happy? For all the reasons given above, reform of the current system of food production by agriculture is unlikely. However, in addition food production by farming cannot be scaled up, except by using more land or by producing from the current land at impossibly high (and likely environmentally damaging) intensities of production. Farming is also constrained technologically by inherent inefficiencies associated with fertilizer production[b], the stochastic effects of weather and disease[c], livestock production inefficiency[d] and the low underlying energy assimilation efficiency of photosynthesis[e]. The high latitude of Scotland in particular also reduces incident radiation which limits production.

Transforming food production: converting CO2 to carbohydrates

In broad terms, solving this conundrum over the coming decades will only happen by increasing food production using the principles of manufacturing rather than those of farming. This requires a technology transition using a combination of chemistry, process engineering, robotics, and genetics.

The key to unlocking the translation of raw energy and chemical inputs to edible outputs, is to split CO₂ to create formaldehyde, methane, or glycerol (a refined version of the Formose Reaction¹² which is currently at ‘Technology Readiness Level’ TRL 3-4)[f] as intermediates to produce carbohydrates like glucose, maltose, galactose, fructose, sucrose, and starch^12,13. These can either be used directly to formulate foods or fed into biogenic reactors to produce proteins and oils which can then be used in food formulation (currently at TRL 8-9)¹⁴. Most of our knowledge about these processes involving the chemical synthesis of food from CO₂ derive from research to support space missions¹⁵ but they are also recognised as having potential to be scaled to create food production systems on Earth and which have greater efficiency than current food production systems^13,16.

At the core of this is energy to split CO₂. Solar or other renewable energy (possibly including Small Modular Nuclear Reactors) would be needed as the basic input but would have the potential to make food with negative greenhouse gas emissions. Using CO₂ from flue gases used to burn biomass for heat production would add further to the advantages of such a process. The chemical outputs could be used as feedstock for current micro- and macro-biological systems of food production. The eventual aim would be to produce carbohydrates at megaton scales.

This kind of manufacturing could make a significant step towards decoupling human food production from resource consumption. Agriculture is 2-5 times less resource efficient than the next-least efficient industrial sector meaning there is vast scope for transformation. There are many reasons for this low efficiency (some mentioned above) but reducing these requires out-of-the-box thinking and action. For example, photosynthesis produces carbohydrate at about 1% efficiency; energy harvesting by photovoltaics (or from wind power in Scotland) could produce carbohydrate with an efficiency of >6%^13,16,17. Analysis for space missions shows that this non-biological route to carbohydrate production, if appropriately optimised and scaled, and if connected to sources of renewable energy, is the most promising route by which to achieve human sustainability¹⁵.

Optimisation and systematisation are needed to make this kind of production system price-competitive with traditional agriculture. Scotland is well-placed to be a leader in this field because it has abundant renewable energy, abundant freshwater, high quality research, a substantial chemical industry and a local need to reform its approach to food production in order to enhance food security, reduce damage to the environment and meeting its greenhouse gas reduction targets. I suggest that the Scottish Government, with the input from the RSE, should sponsor the production of a report about the opportunities there are for Scotland to build added value into its renewable energy resources by building production processes for feedstock to supply the global food industry. This could be a new era in industrial chemistry for places like Grangemouth.

• This article is part of a series from the RSE’s Environment Community of Interest. The aim is to stimulate informed public debate on the many aspects and elements of this complex and vexed subject. We’d love to hear your thoughts about this piece, email us on publicpolicy@therse.org.uk.
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• The RSE’s blog series offers personal views on a variety of issues. These views are not those of the RSE and are intended to offer different perspectives on a range of current issues.

References

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3 Godfray, H. C. J. Food and Biodiversity. Science 333, 1231-1232 (2011). https://www.science.org/doi/10.1126/science.1211815

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12 Lambert, J. B., Gurusamy-Thangavelu, S. A. & Ma, K. B. A. The Silicate-Mediated Formose Reaction: Bottom-Up Synthesis of Sugar Silicates. Science 327, 984-986 (2010). https://www.science.org/doi/10.1126/science.1182669

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[a] Food chain efficiency is defined here as the percentage of energy and materials within food which could have been grown or allocated for the purpose of feeding people, is lost as a result of reallocation for other purposes.

[b] Fertilizer production uses about 2% of global energy production and 1.4-5% of global greenhouse gas production

[c] The effects of extreme weather are forecast to create greater challenges for conventional agriculture. Both climate change and global trade (because of the disease it tends to transport) are also forecast to increase challenges from disease.

[d] See note a

[e] When operating optimally, plants normally convert only 3-6% of the sunlight they are exposed to into energy. This compares with more the 20% for contemporary photovoltaic cells used on domestic roofs.

[f] Technology Readiness Levels are used to assess the progress in a technology towards full scale use. It is on a scale of 1-9, where 1 is a new insight or invention and 9 is a fully commercialised product.