A colleague at an apparel brand recently shared this Atlantic Magazine article, written by Gabriel Popkin and Quanta Magazine on soil carbon sequestration. It was an excellent read, and sparked Dr. Samantha Mosier in our discussion group to share a second article, All Soil Carbon is Not Created Equal, written by Jocelyn Lavellee and Francesca Cotrufo on the same topic – another great read for those working in the field.
Both articles provide helpful insights into soils, but it struck our team at Native that the Atlantic’s article may be manufacturing a dichotomy between dynamic and static soils that we have not found to be in play, and that our experience is not only shared by our partners such as Dr. Mark Ritchie, but likely by other practitioners who are currently working on soil health and soil carbon sequestration in practice.
The article posits that the IPCCC and others have over-forecast the role soils can play in sequestering carbon and, by extension, in helping limit temperature increases to 1.5 degrees Celsius by 2050. This over-estimation, according to the article, is a result of forecasters assuming all carbon that goes into the soil remains in the soil, rather than recognising the dynamic cycling of carbon amongst the atmosphere, plants, soil, and the creatures living in that soil.
At Native, our focus since 2000 has been catalyzing specific types of climate action – practices, behaviours, and technologies – left behind by existing incentives and conventional investment structures. As of 2018, this included initiatives to sequester carbon in soils through the managed grazing of livestock, so we thought it would be helpful to share our own experience. Thanks to local partners like Western Sustainability Exchange in Montana, leading ranchers in the northern Great Plains region of the U.S., and scientists like our partner Dr. Mark Ritchie, we have come to appreciate the dynamism of soils. Thanks to our long history of designing, building and operating climate action projects with twenty-year or longer operating lifetimes, we have also come to appreciate the extreme importance of never over-estimating the climate benefits of any single undertaking.
Our soil carbon modeling is designed to forecast how much carbon may accrue in a given hectare of soil if livestock are grazed on that soil in a sustainable way over a given period of time, and provides a view of all types of carbon that may move into the soils. From this modeling we look only at the figures for carbon that is forecast to move into the deeper layers of those soils. It is only that amount we estimate to remain in the soil for a meaningful period, and it is that amount our actual soil carbon measurements will confirm or refute over a thirty-year period, and beyond. In this way, we are very careful not to over-estimate the role agricultural soil carbon sequestration can play in our 1.5C future.
And while we believe that role to be highly significant, we also see soil carbon sequestration only alongside a myriad of other efforts that transform our food systems, our energy infrastructure and our built environments, as Johan Rockström clearly outlines in his recent TED Talk: 10 years to transform the future of humanity, or destabilize the planet.
And the good news is that there are many reasons to increase soil health through livestock grazing management. Even in a scenario where soils hold less carbon than predicted over the long term, and if the long-term measurements were to show this to be true, ranchers and farmers will still reap the benefits of improved forage and drought resilience; ecosystems will still be protected with less erosion, healthier riparian zones and wildlife habitat.
Our take-away from the Atlantic article is that we hope it does not sew seeds of hesitancy to act and to include sequestration and improving soil health as part of a climate strategy. While there is much to learn – and we ourselves pledge to share what we are learning from putting the science into practice with ranchers across the globe, from the U.S. to Kenya to Argentina – there is still much to do.
We have spent too many decades doing too little. Let us be cautious, pragmatic, rigorous and transparent so that we can take the necessary steps forward and take the actions we know we can take now. Let us make conservative forecasts, then track and measure ‘actual’ outcomes, so we can direct investment into those actions that prove impactful, while also investing to learn what more we can add to the growing list of exciting ways to transform into a zero carbon future.
To continue the conversation on soil carbon with Native, check out our podcast with Sustainability Defined.