We need to re-examine the relationship between agriculture and climate.
Today, agriculture is a major contributor to challenges facing our environment: land degradation, aquifer depletion, nitrogen runoff and greenhouse gas emissions, to name a few. These challenges are contributing to changing the composition of our atmosphere. Last month, scientists recorded the highest concentration of atmospheric carbon dioxide in human history: 415 parts per million (ppm). That represents an increase of 135 ppm since the start of the industrial revolution. Multiplied by the total volume of the atmosphere, 135 ppm is equal to one trillion tons – or a teraton – of carbon dioxide increase over the past 200 years.
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Despite the role that it now plays in contributing to the problem, agriculture also offers the most scalable, immediate and affordable solution for removing carbon dioxide from the atmosphere. This solution leverages a natural process that every plant undergoes, powered by a source that is always available, costs little to nothing to run and does not cause further pollution. This power source is the sun, and the process is photosynthesis.
A plant takes carbon dioxide out of the air and, with the help of sunlight and water, converts it to sugars. Every bit of that plant – stems, leaves, roots – is made from carbon that was once in our atmosphere. Some of this carbon goes into the soil as roots. The roots, then, release sugars to feed soil microbes. These microbes perform their own chemical processes to convert carbon into even more stable forms.
We have a trillion-ton problem, which cannot be addressed by the photosynthesis of a single plant. But when it comes to agriculture, we are not talking about one plant – we are talking about tens of thousands of plants per acre, and 3.6 billion acres of farmland worldwide. All of these acres, before they were cultivated, had soil carbon levels of between 3% and 7%. Today, they are at roughly 1% carbon. If every acre of farmland were returned to a soil carbon level of just 3%, one trillion tons of carbon dioxide would be removed from the atmosphere and stored in the soil. Again, a teraton. The size of the potential solution is equivalent to the size of the problem.
Putting carbon back in the soil
So how do we increase the carbon content of soil, while still cultivating the land? A small percentage of farmers are already doing this by employing practices known as “regenerative”. Five important regenerative practices are planting cover crops, no-till farming, rotating crops, reducing chemicals and fertilizers, and incorporating livestock. These practices are proven to both drive carbon into the soil, and keep it there. The resulting carbon-enriched soils are healthier, demonstrating better resilience to extreme weather, improved water permeability, increased microbial diversity, higher yields, reduced input requirements and even more nutritious harvests – all of which is better for both the land and the farmers’ bottom line.
If farmers provide the societal benefit of removing atmospheric carbon by adopting regenerative practices, it seems reasonable that they should be compensated for their effort. Today, the average farmer in the United States is making less than $40 per acre. If carbon is priced at $15 - $20 per ton, and growers adopting regenerative practices can capture 2 - 3 tons of carbon per acre annually, that represents an additional $30 - $60 towards their bottom line. This significant profitability boost is further supplemented by the economic benefits of transitioning to regenerative practices, such as lower input costs and higher yields. $15 - $20 per ton is also much less expensive than proposed alternatives for removing carbon dioxide from the atmosphere.
The potential to remove one trillion tons of carbon dioxide from the atmosphere is in our hands. We are not dependent on new technological breakthroughs. We know how to do this today. We just have to decide, collectively, that we are going to make it happen. This is an inherently collaborative effort, because the cost of transitioning global agriculture to regenerative practices cannot fall to farmers alone. It requires consumers, companies and governments to demand that food is grown in a climate-positive way, and that farmers are paid for their stewardship.
To be clear, I am not suggesting that a sole focus on agricultural soils is enough to address climate change. We still need to cut emissions. We still need energy systems that are sustainable. And we need widespread awareness of how everyone can reduce their footprint. But when capturing and storing carbon dioxide in the Earth's soils is paired with reducing our emissions, we have a real hope of not just slowing our advance towards the climate cliff, but stopping, turning around, and walking the other way.