Soil carbon - what is it good for?

A while back I was on a soil carbon working group with the Science for Nature and People Partnership (SNAPP). Our recent journal article is about soil carbon and soil health. It’s a good read, and only 1,800 words: https://www.nature.com/articles/s41893-019-0431-y or https://rdcu.be/bWGfa if you don't have access.



The lead author did a phenomenal job getting the text to be clear and succinct, and the opening two lines actually sum it up very well:
"Soil-based initiatives to mitigate climate change and restore soil fertility both rely on rebuilding soil organic carbon. Controversy about the role soils might play in climate change mitigation is, consequently, undermining actions to restore soils for improved agricultural and environmental outcomes."

In other words: scientists disagree about how effective soil carbon is as a climate change mitigation strategy. We disagree a lot - more than you'd expect. Everything from "this is our best bet to start scaling up now" to "building soil carbon will not result in any net climate mitigation." So we argue about it a lot.

But that debate hides the fact that we generally strongly agree that rebuilding soil carbon is good for farmers and ranchers. Most agricultural soils have lost carbon over time. Regaining it can mean less erosion, better water retention, and better crop resilience to stress. With good management it can even mean less fertilizer use and cleaner water. How much carbon is ideal in different landscapes, and how to best increase it, varies. But it's worth remembering how strong the consensus is on the value of building soil carbon from an agricultural perspective.

Read the paper here: Soil carbon science for policy and practice
There's also a press release here: Building A ‘Solution Space’ for Soil

reThink Soil: A Roadmap to U.S. Soil Health

We just released a new report on the potential benefits of adoption soil health practices in the U.S., and the conclusions are pretty exciting! You can read a brief overview, the executive summary, and the full paper at http://nature.org/soil. Much of the analysis was done by consultants we worked with, but I provided lots of scientific guidance and review throughout the process.

The web page has a good summary of some of the key points, but to put it even more succinctly, we argue that the adoption of three soil health practices (no-till, cover crops, and crop rotations) on U.S. row crops could have massive benefits both to society (e.g. improved water quality, reduced GHGs) and to the farmers implementing them (reduced soil erosion, improved soil quality and resilience).

For instance, if half of the farmland used to grow corn, soy, and wheat were to adopt all three practices, it could generate $7.4 billion in total benefits, and if all the farmland for those three crops adopted them it could be $19.6 billion (note that it's not double because some farms already use some of these practices). If you take the more optimistic upper range of our estimates, total societal benefit for 100% adoption of all three practices could be $49.8 billion. A lot of the science is uncertain, so these estimates are rough but we drew on the best available data to come up with them, and we are confident that the magnitude of the opportunity is valid even if the exact numbers are off.