Here's a tangible plan to restore soil health in the next ten years

This year, COVID-19 has understandably dominated our attention - but another crisis is unfolding silently, beneath our feet.

More than a third of the world’s soil is already degraded, and the IPCC estimates that could rise to 90% by 2050 if nothing is done. Even moderately degraded soil produces 30% less food and stores around half the water of healthy soil.

Yet by 2050, we will need to produce up to 60% more food while nearly half the world’s population may live in ongoing drought conditions. Without action, the conflict between humans and wildlife - the root cause of this year's pandemic - will only intensify. Fixing soil would go a long way to alleviating this conflict by helping secure future food supply, reducing water stress, and mitigating climate change.

Of the three great bisospheres – soil, ocean, atmosphere – soil is the only one we have a fighting chance of remediating within a couple of decades given current technologies.

The need to fix soil health is hardly an original idea. Yet progress on a global scale has been painfully slow, for several reasons:

Recent science may take us a long way to an answer.

In particular, combining 176 years’ worth of soil data from the world’s oldest continuous scientific experiment (the Broadbalk and other long-term experiments at Rothamsted, England) with modern digital technology and systems analytics has given much more precise quantitative understanding of soil’s role in the carbon cycle and of carbon’s role in soil health. Three benefits stand out.

First, the work has confirmed three critical determinants of the functioning of any soil system – capacity, efficiency and resilience. Capacity is the ability to translate water and nutrients into outputs such as food. Efficiency relates to energy flows – how much energy is converted to outputs rather than dissipated? Resilience is soil’s ability to store water and nutrients until conditions improve. This is a framework to make sense of the enormous diversity of soil and climate across our planet while providing a much improved qualitative and quantitative understanding of the micro-scale processes involved.

Second, the work has enabled the prototyping of reliable, quick and low-cost measurement of soil health in real-time using networked digital probes. Access to these data in real-time has the potential to rapidly progress a “how to” library of best practices for soil health across geography and climate while providing objective measurement and hence the basis for relevant private or public incentives. Thinking has commenced on the protocols which would be needed to underpin this on a global scale.

Third, we now have, for the first time, a mechanistic theory for how carbon moves from the atmosphere to become stored in the soil, and the co-benefits that emerge. This, combined with the measurement break-throughs, is a step-change in using soil management practices and incentives to sequester carbon and improve those three critical determinants of the functioning of any soil system – capacity, efficiency and resilience.

In parallel with this progress, another key advance has been a decisive shift in some of the largest global corporates’ interest in soil health remediation, both as a profit opportunity and as a way of contributing to the Paris commitments. The above advances in soil science and measurement have been instrumental in igniting this corporate interest. They understand that, with cheap and reliable measurement in prospect, there is scope for effort, benefits, and incentives for soil remediation to be aligned.

This shift is happening at a time when the traditional institutions of global governance are becoming increasingly fragmented. A tendency for governments to “go-it-alone” with their COVID responses has resulted in startling disparities in the economic and social outcomes.

As the World Economic Forum’s Global Risks Report 2020 highlights, “waiting for the geopolitical system to ‘snap back’ would mean missing our last chance to address the world’s most pressing challenges.” Global corporates have the reach and governance to make an impact at the scale and pace required. These discussions have a long way to run, but are a hopeful sign of bringing serious corporate fire-power to the task.

The magnitude of the global task means that there will need to be deep pockets. However, the science points to an even more fundamental reason for tackling this through a network of global corporates – risk mitigation.

In particular, our increased understanding of soil health has highlighted that while soil carbon takes one or two decades to build up, stress events – for instance, drought or fire – can reverse that progress quickly. Here we need to turn to one of the staples of risk mitigation – the pooling of individual exposures into more robust portfolios. Pooling of global soil health initiatives will be critical so that localised stress events can be absorbed within an envelope of global progress. This is also one reason that we hope to attract at least one global insurance company – ideally more – to these corporate efforts.

This question of risk mitigation points us to another challenge that is only partly solved – the issue of public vs private benefits and costs. Recent science has helped us understand and quantify the public and private benefits of soil health. However, the heritage of economic analysis of public vs private goods is one of focussing more on the stream of positive benefits (and associated costs) rather than explicitly focusing on the mitigation of risks. In the case of soil health, we need to focus on the full suite – benefits, costs and risks – both in the public and private sphere. To repeat the earlier point, of the three great bisospheres – soil, ocean, atmosphere – soil is the only one we have a fighting chance of remediating in within a couple of decades given current technologies.

Farmers and farming practices are front and centre in thinking about soil health restoration. We need to build a new partnership with farmers but also widen our focus. Forestry practices are an obvious candidate to benefit and contribute. Water utilities are another candidate – for instance, quantifying soil’s ability to store water allows cost-benefit analysis of dam construction versus soil remediation for drought and flood alleviation. Likewise, we know how to minimise the run-off of fertilisers into watercourses, allowing us to quantify rational incentives to reduce run-off. The waste industry will be a critical source of carbon and nitrogen inputs for soil remediation. In short, our better understanding of the role of soil in the global carbon cycle allows a much wider focus, notwithstanding that farming practices need to remain central.

Can we restore global soil health in ten years? Do we have any choice?

The ideas articulated here have emerged from an ongoing collaboration with Prof Hugh Harley, University of Sydney and a group of global corporates.