Groundbreaking research suggests that making marginal improvements to agricultural soils worldwide could play a significant role in mitigating global heating and keeping the planet within the critical 1.5-degree Celsius threshold.

Farming techniques that enhance long-term fertility and yields also have the potential to increase carbon storage in soils, yet they are often overlooked in favour of intensive practices reliant on excessive artificial fertilisers, leading to increased greenhouse gas emissions.

Recent data indicates that implementing better farming techniques to store just 1% more carbon in approximately half of the world’s agricultural soils would be sufficient to absorb approximately 31 gigatonnes of carbon dioxide annually. This amount is remarkably close to the 32 gigatonnes gap between current planned global emissions reductions per year and the amount of carbon that must be cut by 2030 to stay within the 1.5-degree Celsius limit.

These estimates were carried out by Jacqueline McGlade, former chief scientist at the UN Environment Programme and former executive director of the European Environment Agency. Presently, she leads Downforce Technologies, a commercial organisation specialising in selling soil data to farmers. Leveraging publicly available global data, satellite images, and lidar technology, the company can now assess in detail how much carbon is stored in soils down to the level of individual fields.

McGlade emphasises that while farmers may face initial costs during the transition away from the excessive use of artificial fertilisers, their efforts will pay off in the long term. After two to three years, farmers can expect improved yields and healthier soils. Restoring 40,000 hectares (99,000 acres) of currently degraded farmland in Kenya, a region home to approximately 300,000 people, is estimated to cost about $1 million.

“Outside the farming sector, people do not understand how important soils are to the climate,” said McGlade. “Changing farming could make soils carbon negative, making them absorb carbon, and reducing the cost of farming.”

Moreover, the data provided by Downforce Technologies empowers farmers to potentially sell carbon credits based on the additional carbon dioxide their fields are absorbing. Soil has long been recognised as one of Earth’s major carbon stores, but until now, the ability to assess how much carbon soils in specific areas retain or emit has been limited. According to UN estimates, about 40% of the world’s farmland is now degraded.

Carbon dioxide removal, encompassing a range of technologies and techniques aimed at increasing the uptake of carbon dioxide from the air and sequestering it, is a growing area of interest. As the world approaches the critical 1.5-degree Celsius threshold of global heating above pre-industrial levels, the need for effective carbon sequestration solutions becomes increasingly urgent.

For arable farmers, sequestering more carbon within their soils could involve altering crop rotation, cultivating cover crops like clover, or adopting direct drilling techniques, which eliminate the need for plowing. Livestock farmers, on the other hand, can enhance their soils by growing more native grasses.

In addition to farming practices, hedgerows also play a crucial role in carbon sequestration within the soil. These hedges possess extensive underground networks of mycorrhizal fungi and microbes that can extend several meters into the field. Unfortunately, farmers have historically removed hedgerows to facilitate intensive farming, but restoring and maintaining these natural barriers can lead to improved biodiversity, reduced topsoil erosion, and decreased agricultural runoff, a significant river pollutant.