With the United Nations Climate Change Conference (COP28) underway in Dubai this week, agriculture is once again a key topic. Half of the Earth’s habitable land is farmland, and when fields are disrupted with heavy machinery, the soil – which stores three times as much CO2 as the atmosphere – releases large amounts of this trapped carbon.
The discussion couldn’t be more timely: last month, a new paper from a team of scientists, including researchers at NASA and Columbia University’s Earth Institute, suggested that the world will cross the 1.5 degrees Celsius warming threshold by the end of this decade.
The good news is that around the world, scientists are working on ways in which agriculture can become part of the climate solution, helping to restore the environment instead of adding to its burden. Here are five particularly promising solutions.
Soil Carbon Capture
Regenerating soil could improve its ability to act as a carbon sink, successfully locking in greenhouse gases. Studies have predicted that improving soil and land management, like reducing tillage and increasing nitrogen-fixing legumes, could offset somewhere between five and 10 percent of global greenhouse gas emissions.
One promising approach is enhanced rock weathering, which based on the ability of silicate rocks to draw CO2 down from the atmosphere as they erode over tens of thousands of years. Climate scientists are looking to accelerate this process of carbon removal through crushing large silicate rocks into fine particles, and adding this to the soil.
“CO2 is fixed as bicarbonate molecules which is then washed through soil, into rivers and ultimately the sea where they’re fixed in the ocean for probably hundreds of thousands of years,” says Steve McGrath, Head of the Sustainable Agriculture Sciences Department at Rothamsted Research in the UK.
Another exciting approach is adding beneficial microbes to the roots of crops, which accelerate the conversion of CO2 into minerals that permanently remain in the soil. Leaps portfolio company Andes has partnered with farmers in the Midwest to deploy its microbial seed treatment on 50,000 acres this year, with more expansion expected next year. Its microbial solution offers an additional income stream for farmers whose fields become carbon sinks – a win, win, win for people, farmers, and planet.
Cover Cropping
Cover cropping is another major way of changing soil carbon content through encouraging farmers to minimize tillage and protect the soil by covering it with grasses, legumes and other plant life that can help to pull CO2 from the air through photosynthesis.
Last year, a paper from scientists in the U.S. and Morocco suggested that cover crop practices could help to convert many hot and dry Mediterranean ecoregions, which occupy nearly 15% of the total global land area, into significant carbon sinks.
One innovative cover cropping technology being explored in the U.S. is CoverCress, originally a Leaps investment that is now majority owned by Bayer. It is a rotational cash crop that combines both grain production and the environmental benefits of a cover crop without disrupting other harvests. The seed oil extracted from CoverCress grain is designed to have a lower carbon intensity score, with research suggesting that it could yield a sustainable aviation fuel.
Alternative Proteins
The need for more environmentally friendly replacements to conventional meat farming remains as strong as ever. COP28 will be the first climate change conference to have a major focus on food, highlighting that animal-based food systems are responsible for a third of all human-driven greenhouse gas emissions.
In the coming years, more hybrid combinations of plant-based proteins and fermentation-derived proteins are anticipated to reach the market, as a way of solving ongoing changes in taste, texture, and nutritional value. While the cost of producing cultivated meat remains a major hurdle, production costs have still fallen by 99 percent in less than a decade. Analysts have suggested that if costs follow a similar trajectory to the falling cost of human genome sequencing, cultivated meat could theoretically reach cost parity with conventional meat farming by 2030, with some companies showing progress even faster than that.
Notably, cultivated meat is still real meat scaled up from animal cells in a bioreactor, as opposed to fermented or plant-based alternatives. I recently had the opportunity to taste cultivated ground pork at the pilot facility of Leaps portfolio company Fork and Good in New Jersey. It was remarkable how similar it tasted in terms of texture, flavor, and mouthfeel. If this meat was in my dumpling, I would truly never notice a difference.
Sustainable Irrigation
Earlier this year, David Hannah, Professor of Hydrology at the University of Birmingham, wrote that sustainable water management could act as the ‘climate connector’ at COP28, initiating collaborations to build the planet’s resilience to climate change.
If this is to happen, there is a need for greater investment in new sustainable irrigation technologies, practices that do not deplete water in rivers, lakes, and aquifers, or impair environmental flows.
Dr. Lorenzo Rosa, a principal investigator in the Department of Global Ecology at the Carnegie Institution for Science at Stanford, highlighted solar-powered drip irrigation systems as an example of a more environmentally friendly technology. These systems use small solar-powered pumps to deliver precise amounts of water directly to the roots of crops, reducing water waste in the process.
“This is a water efficient low-carbon irrigation technology which should be implemented,” says Rosa. “However, adoption has been very slow.”
As with cover cropping and soil carbon capture, Rosa believes that policy incentives are required to convince farmers to commit to technologies that enable the production of food with less water. With climate change set to increase the year-to-year variability of water resources, there is also a growing global need for next-generation water storage facilities that can help reduce water scarcity.
One promising new way of storing water is called managed aquifer recharge, which refers to the intentional release of water back into layers of porous rock or sediment where it can be stored for subsequent use. Porous rock contains microscopic spaces through which liquid or air can pass. This would avoid some of the negative environmental impacts of storing water in large dams. Research has previously highlighted that the creation of such dams involves flooding vegetation or deforestation, reducing the natural absorption and fixation of atmospheric carbon dioxide.
Using Biologicals Instead of Synthetic Fertilizers
While global food systems are heavily reliant on synthetic nitrogen fertilizers to keep crop yields high, the production of these fertilizers was responsible for 2.1% of all global greenhouse gas emissions in 2018, according to a study published in Scientific Reports last year.
Investing in fertilizers derived from naturally occurring substances, called biologicals, represents another path to reducing the carbon impact of agriculture. One example is biochar or biological charcoal, which can be made from either human or animal waste and stabilizes carbon, which is released more slowly back into the atmosphere.
Studies have estimated that adding biochar to agricultural soil could help sequester between 0.3 and two gigatonnes of CO2 every year between now and 2050. Because biochar has a distinct honeycomb structure, it can also store nutrients and water, improving the quality of the soil and reducing the need for industrial fertilizers.
Such is the growth in crop biologicals that this sector is now forecast to outpace that of conventional agrichemicals towards the end of the decade, with a compound annual growth rate of 14% through 2029.
While agriculture has a significant impact on climate and the health of the planet, there are plenty of strategies at our disposal to improve our practices in the coming years. If policymakers at COP28 and around the world back these solutions, they could go a long way to helping keep the climate crisis in check.
Thank you to David Cox for additional reporting and research on this article.
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