The twin problems of soil degradation and increasing greenhouse gas (GHG) emissions are two of the largest challenges facing the world today. Degraded soils lead to reduced yields and thereby undermine global food security, and what is more they contribute to desertification, exacerbating global warming and feeding a vicious cycle of further land degradation. Meanwhile, emissions of GHGs – particularly carbon dioxide – have continued to climb despite repeated pledges by world leaders to reverse the trend, and global temperatures have reached 0.74℃ above the 1961-90 average. In order to meet the targets set by the Paris Agreement in 2015 and keep global warming to below 1.5℃, global emissions would need to fall by 7.6% per annum between now and 2030.
The link between these two complex global challenges was, until recently, largely overlooked. The world’s soils store an estimated 1,500 gigatonnes of organic carbon, or 1.9x the amount of atmospheric carbon (800 GT). Soils continue to be degraded and eroded; an estimated 24% of global soils now degraded to some extent, including 50% of agricultural soils. Meanwhile agriculture, forestry and other land use together contribute an estimated 24% of total GHG emissions. By restoring soils and increasing soil organic carbon, agriculture could go from being part of the problem to the solution. Indeed, increasing soil organic carbon by just 0.4% per year would stop the rise in atmospheric carbon altogether, thereby mitigating the worst effects of climate change.
How could we bring about such a transformation? The answer is to provide the right incentives for the stewards of the world’s soils, namely farmers. Soil restoration must become a commercial priority for farmers rather than a trade-off and the way to achieve that is to unlock value for those that employ regenerative practices, rewarding them in the form of carbon credits.
The idea of carbon trading is not new; there are already 61 carbon pricing initiatives around the world, covering 22% of global GHG emissions and raising US$ 45 billion of revenues in 2019. There are 14,500 registered carbon crediting projects, generating 4 billion tonnes of CO2 equivalent in carbon credits. However, today less than 2% of this relates to the agriculture sector. Instead, the vast majority of carbon credits have gone towards forestry and renewable energy, despite the fact that the monetary and opportunity costs associated with soil restoration are significantly lower.
What explains this? One key problem is verification: a well functioning market relies upon credibility, and measuring soil organic carbon is a fiddly business requiring soil samples and expensive laboratory tests. Forestry projects (42% of carbon credits over the last 5 years) and renewable energy (33%) are significantly easier to verify and as a result these carbon credit schemes have seen dramatic growth in recent years.
There are several early-stage schemes exploring the agricultural carbon trading opportunity, including Indigo Ag and Nori in the US, and government-backed initiatives in Australia and New Zealand. The USDA’s COMET-Farm tool and the Cool Farm Tool, amongst others, allow farmers to quantify their emissions, biodiversity and water footprint and thereby inform decisions to improve sustainability.
However, the practicality of gathering sufficient data remains a challenge; a truly scalable and affordable solution is the missing piece of this particular jigsaw. The good news is that technology may offer a solution. Hummingbird Technologies is a remote sensing and data science company specialising in crop analytics. We have recently developed the ability to verify certain regenerative agricultural practices, such as tillage type and the use of cover crops. By rolling out this verification technology to farmers and other stakeholders around the world, we hope to accelerate the maturation of carbon credit schemes for the agricultural sector and thereby unlock huge value for farmers whilst facilitating global-scale soil restoration.
Head of Sustainability at Hummingbird Technologies
 Oelkers & Cole (2008)
 Bai et al. (2013)