The best ways the bioeconomy can lower global emissions from agriculture and food
Between 2023 and 2050, the world must avoid or absorb 24.9 gigatonnes of carbon to have a chance of keeping global warming to within 2 degrees by 2100.
Last week’s feature covered how bio-based materials and biofuels can best contribute to these targets. Here, we turn to how bio-manufacturers can bolster carbon reduction within food and agriculture.
We look at why bio-based arable farming inputs, insect-based feed, and bivalve biomaterials are the most effective bio-based strategies for achieving lower emissions in agriculture.
Though historically overlooked by both state and private investors, especially when compared to biofuels and industrial fermentation, the IPCC has highlighted these solutions as among the most cost effective mitigation strategies with the fewest ecological drawbacks.
Why agricultural emissions matter
Bio-based goods don’t just lower net carbon emissions at the point of end consumer use. They also affect global carbon budgets more indirectly by altering how much carbon is stored in land and habitats.
This is because the biobased industries are inextricably dependent on agriculture, forestry, and other land use activities for its feedstock. Also known as the AFOLU sector, it includes all the way that humans can interact with the land and oceans.
AFOLU offers 20-30% of the carbon cuts we need to make by 2050 to limit warming to 2 degrees by the century’s end. All IPCC mitigation scenarios limiting assume a large role for it.
There are two reasons why AFOLU is so key to mitigation. First, according to the IPCC, AFOLU is ‘inextricably linked with some of the most serious challenges … to have ever faced humanity’ like biodiversity loss and environmental degradation. Second, it is also the source of all biomanufacturing feedstock.
After habitat management, agriculture is the part of AFOLU with the biggest potential for carbon cuts. In theory, agriculture could lower its carbon emissions by between 1.8 and 4.1 gigatonnes of carbon dioxide a year. If we take the optimistic upper estimate, this is 114 gigatonnes between 2030 and 2050: well above the global reduction target for two degrees.
Biotech for carbon-storing soil
Their supply-demand relationship means the ability of bio-industry and AFOLU to contribute towards global carbon cuts are closely intertwined.
A lot of whether AFOLU including agriculture will achieve its carbon reduction potential depends on scaling bio-based industries: the calculations for agriculture’s potential carbon cuts assume that some of its biomass will help displace petrochemical products by feeding into renewable goods. Going in the other direction, bio-based industries can enhance the carbon storage of land by sourcing feedstock cultivated using sustainable techniques.
Another way the bio-based industries can boost agriculture’s contribution to global mitigation goals is by innovating in biotech that increases soil carbon storagel. The market is seeing a burst of new bio-based arable farming inputs for just this purpose.
One of them is the company Loam, with their seed coating product CarbonBuilder. In farm-based trials for barley, it increased carbon units stored between three and six times per hectare compared to zero and two under other land management practices.
Another startup, Alkama, is developing a microbial replacement for chemical fertilisers targeted at UK wheat farmers. Its founder ultimately aims to replace all chemical inputs with bio-based ones, while maintaining similar yields.
While the bio-based product Alkama is developing will lower crop yields compared to chemical fertiliser, its selling point is that farmers will save on input costs. The bio-based alternative is cheaper than the fossil based product.
The main hurdle here is incentivising businesses to adopt new and largely untested biotechnologies in what is already a low-margin industry. To overcome this, companies like Loam will often connect farmers to carbon offset markets, providing them with digital technologies to measure how much more carbon crop soils are absorbing after switching to their inputs. Farmers can sell the carbon they are preventing from entering the atmosphere as offset credits.
Alkama’s proposition to farmers is that bio-based may reduce yield but still increase margins by offering a lower price-point compared to chemical fertiliser. What’s more, farmers using their product can gain an organic certification, which could get them a higher price for their products on the market.
Insect feed: low hanging fruit for cutting agricultural carbon
Biotech startups are also marketing carbon-reducing agricultural inputs to livestock farmers. Insect-based animal feed is getting a lot of attention in this area.
Certain species of insects can efficiently digest and convert organic waste into larvae and exoskeletons. These can be processed into energy-dense, protein-rich feed. From a value chain perspective this is important as insects convert low-value, low-nutrient materials into high-nutrient matter.
These low-carbon proteins could replace globally dominant livestock feeds based on soy, which tend to be grown cheaply in places like Brazil at the expensive of biodiverse, carbon-storing forests.
Insect-based animal feed has garnered wide scientific consensus on its carbon-reducing potential, with the IPCC has listing it as one of the most direct and rapid ways that bio-based technologies could help lower agricultural emissions.
It appears that scaling insect-based alternatives is one of the most effective ways that biomanufacturing can contribute to carbon goals. It is also a good example of how bioeconomy-based measures to avoid or sequester carbon emissions from agriculture are so appealing from a mitigation perspective: it avoids the need for immature or untested technologies like carbon capture and has fewer technical barriers to deploying quickly.
A big investment oversight in the bioeconomy right now is bivalve production, one of the few food production systems that can be carbon negative.
One study reckons that expanding bivalve farming could, if expanded within ecological limits, store 1.19 gigatonnes of carbon per year – 17.63% of total 2020 emissions.
Even without expanding cultivation, existing waste pools from the aquaculture industry are huge. In China, around 10 megatonnes of shellfish waste per year is landfilled, hinting at the potential size of a mature circular bivalve sector.
There are many higher value uses for various shellfish wastes. The biggest name in shellfish valorisation right now is London-based Shellworks, which is turning out cosmetics packaging using polymers derived from bivalve waste.
French company Bysco, founded in 2021, uses a byproduct from the mussel farming industry to make an ecological alternative to fibreglass – a material used for the bodies of boats.
A Japanese startup called Hotamet is making protective helmets from the 40, 000 tonnes of shells discarded each year by the northern Japanese scallop food industry. The calcium carbonate content in the shells makes it an ideal feedstock for heavy-duty protective gear.
Ideally, governments would simultaneously subsidise bivalve cultivation under sustainable agriculture programmes while investing into shellfish-based biomanufacturing startups like these. This would expand the feedstock supply and demand simultaneously.
Government support would also open the possibility of targeting investment at end uses where bivalve bio-materials could replace plastic products in the greatest volumes.
So far, however, no country has mounted a circular economy scheme targeted at aquaculture and fisheries waste. This is despite the fact that the carbon reduction gains of bivalve waste valorisation would be high compared to the capital costs needed to kickstart an integrated sector connecting cultivators and bio-manufacturers.
Just as with biofuels and biomaterials, whether and how far agriculture and food-related biotech advances global net reductions goals rests on how it affects land use. The ecological impacts of expanding aquaculture production, for example, are extremely context-sensitive.
The feasibility of AFOLU-based mitigation, including those supported by bio-manufacturing industries, are also hampered by “uncertain permanence”. These are difficulties with predicting how long a certain activity will prevent carbon from entering the atmosphere.
For example, carbon-sequestering bivalve farms will store carbon only for as long as the company stays in business. Yet mitigation measures are only effective when they are durable – atmospheric carbon lingers over very long timescales.
Barriers to bio-based mitigation
Bio-based inputs that increase crop soil carbon retention, insect feed, and the valorisation of bivavlve waste are biomanufacturing sectors with huge climate mitigation potential. They are also among the cheapest economic and technological climate mitigation tools to implement.
The limiting factor here is not technological know-how but funding. The IPCC report says that the $0.7 billion a year already spent on AFOLU carbon mitigation falls short of the $400 billion per year needed to realise its potential.
Nonetheless, the funding needed to decarbonise in AFOLU is smaller than current subsidies given to agriculture and forestry. Diverting a portion of current budgets to fledgling industries in these three areas would go a long way to lowering the carbon intensity of the food system.
The science on these low-cost strategies is clear. The funding, in theory, available. As companies that target emissions from food and agriculture pile up ready for investment and scaling, there is little except political will preventing them from becoming integrated into national and global carbon reduction pathways.