The recent findings suggest that synthetic nitrogen fertilizers speed up the decay process of organic matter so that it is released into the atmosphere as carbon dioxide rather than stored in the soil as carbon. Both plants and organic soils, the studies demonstrate, operate as powerful "sinks," capturing the greenhouse gas considered by many scientists to be largely responsible for global warming.
How organic farming draws down carbon
The current body of soil science shows that all the cropland on Earth, if farmed organically, could sequester 41 percent of all the greenhouse gases in the atmosphere. The pastureland could sequester an additional 71 percent.If just half the world's cropland and pastureland were converted, organic soil could pull 55 percent of annual carbon emissions out of the atmosphere.
Healthy, nutrient-rich soil actually holds carbon dioxide and keeps it out of the atmosphere, where it contributes to the greenhouse effect and a warming planet—a warming planet that's causing more severe storms, weird swings in temperature, more severe allergies, an increase in the spread of insect-borne diseases, and all manner of other health and environmental problems.
The carbon dioxide gets there through photosynthesis, which is the process plants employ to pull carbon dioxide out of the atmosphere, use sunlight to convert it to energy, and then exude the rest through their roots, where the carbon dioxide gets stored in the soil. Microorganisms and beneficial fungi in healthy soil use the carbon dioxide as feedstock themselves, and the result is vibrant, nutrient-dense soil that produces vibrant, nutrient-dense food. (Read more about how eating sustainably grown food is one of the best things you can do for your health.)
Chemical farming doesn't foster that rich carbon-sequestering soil. In fact, through damaging farming practices, such as tilling the soil and growing a single crop year after year, cause carbon dioxide to escape and deplete the soil of nutrients. Farmers try to add them back with nitrogen-based fertilizers, another source of greenhouse gases. Any life left in the soil typically gets killed with pesticides. Livestock farmers add to the problem by cramming large numbers of animals into small spaces, where they produce methane, another greenhouse gas.
Related: Conventional Farming Ruined The Soil On Our Farm—Here's How We Saved It
"The increase in organic matter in the soil also helps preserve bio- diversity," says David Pimentel, Ph.D., a Cornell University agricultural ecologist working in collaboration with the FST. "All organisms depend on biomass—living and dead organic matter. The higher the biomass content, the more the biodiversity. You can see where organic farming and organic gardening fit in there clearly."
Related: Here's How Your Garden Should Change To Accomodate Global Warming
How you can help
Choosing organic produce at the grocery store, and supporting organic and regenerative farmers at your farmer's market, also make a difference. (Young organic farmers especially need your support.)
If you garden at home, garden organically. When you reject chemicals and choose instead to garden organically, Dr. Pimentel says, you address other issues of critical concern by embracing a system that is much less reliant on fossil fuels. "This has implications for our dependence on imported oil and natural gas as well as the climate change problem," he says. "You are preserving the soil and you are reducing the use of chemicals that are directly dependent on fossil energy use."