What is Carbon Farming?
The basic principle behind carbon farming is pulling CO2 out of the atmosphere and sequestering it into the soil, effectively transforming agriculture operations from carbon emitters into carbon sinks.
An article in Modern Farmer lays out the five basic tenets of carbon farming as follows:
- No-Till: focus on perennial crops that don’t need tillage.
- Organic Mulch: cover small-scale plantings with mulch to reduce carbon loss.
- Compost: compost is rich in stable carbon. Spreading it directly over pastures will increase soil richness while decreasing the need for chemical fertilizer.
- Livestock Rotation: periodically moving animals is preferable to letting them graze continuously over a single area.
- Cover Crops: fast-growing plants like clover keep the ground covered through the winter and prevent carbon loss. Combining cover crops with cash crops during the growing season can help offset carbon loss from harvesting cash crops.
In my mind, carbon farming is inextricably linked to regenerative agriculture. In that same Modern Farmer article, Eric Toensmeier, author of The Carbon Farming Solution, argues for the use of “silvopastures,” or the practice of grazing animals among trees to compensate for the carbon released by the animals. For Toensmeier, silvopastures are the most effective way to reap the benefits of carbon farming. Carbon farming techniques like eschewing chemical fertilizers for compost and favoring livestock rotation over open field grazing fit neatly inside regenerative agriculture operations as demonstrated by farmers like Joel Salatin of Polyface Farms, who have already adopted such practices.
In effect, it is nearly impossible to engage in regenerative agriculture without also adopting carbon farming practices. Sure, you can split hairs by claiming that one can assume some carbon farming practices without qualifying as a regenerative operation. However, I will leave splitting hairs (and atoms) to the physicists of the world.
Why do we need carbon farming?
According to Grist, 133 billion tons of carbon, or roughly equal to a fourth of all human emissions since the Industrial Revolution, has been lost through soils. Modernization has only exacerbated the problem. Adding fertilizer to the ground can cause it to emit N2O, a greenhouse gas that is 300 times more potent than carbon dioxide. Farming techniques contribute to twenty-four percent of global greenhouse gas emissions and ten percent of the U.S. carbon budget.
By contrast, according to an MIT Review article, a 2018 National Academies of Sciences report claims global farmland could capture and store 3 billion tons of CO2 if farmers engaged in carbon farming practices. Furthermore, according to research from the Marin Carbon Project, sequestering 1 ton of CO2 per hectare on half the rangeland in California would offset 42 million emitted tons of CO2.
The good news is, thanks to pressure from dedicated activists, the legislature appears motivated to act. Under the Growing Climate Solutions Act of 2020, farmers would get credits for finding ways to reduce carbon emissions on their land. The farmers’ assigned credits could be sold on the market for $13-17 to groups looking to offset their emissions. (Although several organizations have written an open letter arguing the bill doesn’t go far enough.)
Why is carbon farming a hot button issue? (And why you shouldn’t necessarily trust the critics.)
Skeptics have pointed out that offsets do not discourage polluters from changing their habits. Furthermore, critics of carbon offsets as an efficient market argue it’s hard to determine how and if purchased offsets are being applied correctly.
WSTP interviewed Diego Saez-Gil, CEO and founder of Pachama, who’s combating that skepticism through transparency. In our episode “Diego Uses Artificial Intelligence to Make Carbon Credits Count,” Lex, Tony, and Diego discuss how Pachama uses satellites and computer engineering to certify that the carbon offsets companies buy are truly extracting the carbon as promised.
Verifying carbon offsets should mean less hesitancy for their adoption among green groups. However, it doesn’t address the most prevalent criticism of carbon farming, which is measuring soil carbon sequestration.
Arguably the most famous detractor is UC Berkeley Professor Ronald Amundson, and his 2018 paper arguing seasonal variation made measuring the amount of soil carbon too challenging. Additionally, in his WRI report, Tim Searchinger argued it was more beneficial to stop clearing land for farms, citing limitations on soil sequestration and limited updates to farming practices.
However, in an interview for the MIT Review, Calla Rose Ostrander of the Marin Carbon Project noted that the goal of carbon farming projects wasn’t just to sequester carbon but also to create agriculturally productive and climate-friendly soil.
Searchinger’s argument is primarily where I think critics get it wrong. Too often, any proposed climate solution is expected to immediately out-perform the status quo or risk being considered a failure and unworthy of future investment. However, reason suggests this is not how innovation works. As an example, let’s look at the resoundingly successful Obama-era SunShot program. The goal was to reduce the price of solar panels to make it competitive with coal. While solar is now infinitely cheaper than coal, that wasn’t true initially, and the transition didn’t happen overnight. Instead, it took years of investment and refinement.
It is almost as if critics assume environmentalists believe a single proposed solution to be a proverbial “silver bullet” to solving the climate crisis. On the contrary, as an environmentalist myself, those working on climate solutions are some of the most self-critical and intersectional minded people I know.
I believe critics of carbon farming fail to acknowledge the full scope of what the practice entails and how the field has already “grown up” through technological innovation.
Although in the past measuring carbon sequestration has been challenging, according to Wired, there are new handheld sensors for measuring carbon becoming available, as well as computer modeling that can account for seasonal variability.
Environmentalists accomplish nothing by endlessly splitting hairs and segmenting climate solutions. Instead, we need to collectively focus on ways to improve practices fast enough to make a difference. Take Carbon180, for example. In a Medium article, they laid out six ways to help the agricultural sector and the environment, including:
- Expanding the USDA’s conservation programs to improve soil health and carbon storage.
- Create a network of soil carbon demonstration trials (as many producers are unfamiliar with soil health practices.)
- Establish a national on-farm monitoring system.
- Bolster forest restoration efforts and hazardous fuels management efforts.
- Expand in reforestation efforts on public land.
- Invest in innovative wood technologies.
Climate change is a solvable solution. All that’s required is for us to build off each other’s ideas, rather than trying to tear them down.