Regenerative Agriculture to Combat Climate Change and Feed the World (5-minute Read)
A few posts ago, I talked about regreening, afforestation and reforestation. Let’s dive a bit deeper here. Humanity and the sustainability revolution also includes agriculture. IPCC has made it clear that regenerative agriculture is one of the keys to solving the climate crisis.
Soils are where our farmers grow foods and raise domesticated animals. Civilization began several thousand years ago when early human learned how to cultivate plants for food instead of just hunting and gathering. Soils are a natural carbon sink, storing several times more carbon than the atmosphere. But global soil carbon stocks have been declining due to the conversion of landscapes to croplands and overgrazing from increasing livestock. The global agriculture sector needs to close an estimated 11-gigaton GHG gap between expected emissions in 2050 and those needed to hold global warming below 2 degrees Celsius, while increasing food productivity to feed a likely population of 10 billion. We cannot afford to let the health of soils deteriorate, become unproductive and possibly deserts.
Regenerative agriculture is a land management practice that prioritizes soil health by rebuilding organic carbon and can improve carbon sequestration of soil and increase its water retention and reduce erosion. Key practices include no- or low-till farming, the use of cover crops and crop rotation, agroforestry (farmland integrated with trees and shrubs), nutrient recycling, the use of biochar (charcoal-like, thermally decomposed biomass), and managed livestock grazing.
Tilling has been practiced by farmers for millenniums. By plowing the soil, farmers can disturb the roots of weeds and bury the stubbles of harvested plants in the soils. However, in doing so, organic matters are exposed to the air, digested by bacteria and carbon is released into the atmosphere as a result (and nitrous gas as well from decayed fertilizers). Other than tilling, heavily mechanized industrial farming also promotes monocropping, and also commonly exposes farmland after harvest. Such practices limit the ability of soils to replenish nutrients, and exposed soils are the major reason of soil erosion. Mind you, ecologists tell us that it takes 1,000 years for nature to give us one meter of soil. It is a sin for us to let soil to become futile and got blown away. Our ancestors and many indigenous people had learned that crop rotation and planting cover crop during fallowing were useful methods to maintain the fertility of farmland and also retain it.
Good news is non-till farming is becoming more popular, especially in the US, thanks to the good work of the Department of Agriculture and many non-profit organization.
Prevention of overgrazing is another old agricultural practice. In the old days, grassland was allowed to recover after grazing and so the organic matters in the soils could be maintained and grass could grow again for grazing again. According to one study, the use of cover crops on 85% of annually planted US cropland could sequester around 100 million tons of carbon dioxide per year, offsetting about 18% of US agricultural production emissions and 1.5% of total US emissions. The sequestration potential of cover crops would be up to about 0.55 gigatons of CO2 per year if applied to 25% of global cropland. A gigaton is roughly equivalent to water in 400,000 Olympic pools.
Industrial husbandry operations raise animals in close quarters, deploy growth hormones and massive amount of antibiotics, feed them with soy or corn meals and hays harvested from monocrop farmland which uses fertilizers and pesticides. The energy input for one pound of beef is 20 times of most plant-based food. Such practices exacerbate our reliance on fossil fuel and further degradation to farmland besides make us unhealthy. One of the many ways to reduce GHG emissions is to eat food varieties lower in the food chain, or simply plant-based diet.
The application of biochar can sequester carbon and improve the condition of some soil types and improve food security by improving yields by as much as 25% in the tropics. Biochar is wood treated under heat without oxygen, a process known as pyrolysis. It is a very stable form of carbon, decays over a very long period, is made mainly from waste wood and can help soils to retain water and prevent soil weathering. The world has not yet widely produced and used biochar but its benefits are quite well known. We hope that government policies and farmers will help to increase its application.
Continued work and research are needed to address uncertainties about the technical and practical potential of carbon sequestration in soil and vegetation. Importantly, sequestered carbon must remain in the ground, untouched – and not re-emitted from future land use changes – in order to contribute to climate change mitigation. Agricultural solutions must be scalable for significant (large-scale) emissions reductions. Growing human populations, and the increasing demand for animal products, continue to put pressure on food productivity and incentivize further land use change. Soils have reduced capacity to sequester carbon at higher temperatures, so the potential for increasing soil organic carbon will likely decrease as climate change intensifies this century.
All in all, carbon sequestration in soil and vegetation has the technical potential to reduce atmospheric CO2 levels by 156 ppm this century. This alone can solve a huge part of the GHG emission problem that brings us climate change.
Based on several studies, farmers using regenerative practices may see greater profits and greater resilience to climate change. Therefore, eating organic foods is not just a fad, or to be trendy. It is equitable for farmers, good for our health, reduces GHG emission, protects soil fertility for our future generations and lessens (may be eliminate) the need to turn forests and wetlands into farmland.