The “State of Carbon Dioxide Removal” report is one of the first independent assessments of how much CO2 is currently being removed from the atmosphere, and how much will need to be scrubbed out, year after year, to stabilize greenhouse gas levels by midcentury. It’s an important contribution to the climate conversation and a topic that will be getting a lot more attention going forward.
But here’s where the report misses the mark: It underestimates the enormous potential for Mother Nature to do the work of carbon removal herself. And in that same vein, it fails to acknowledge a growing frontier of technological innovation that can aid and significantly amplify the power of natural climate solutions.
The authors of the Oxford report call for an aggressive ramp-up of “novel” CO2 removal strategies. These range from low-tech biochar and biofuel production with carbon capture and storage, to more fantastical contraptions such as mechanical trees and other machines designed to suck CO2 out of the air and convert it to carbon bricks, or other storable forms. The report finds that carbon dioxide removal from new technologies must increase “by a factor of 30 by 2030… and by a factor of 1,300 (up to about 4,900 in some scenarios) by mid-century.”
While I heartily support novel, climate-smart technology investments — I routinely celebrate them in this column — we are still years if not decades away from developing machines that can perform carbon dioxide removal on a scale that’s even close to what nature can do. Billions of dollars are being invested in so-called direct-air-capture technologies (mechanical trees and the like), but none yet have succeeded at scale.
Meanwhile, forests, grasslands and well-managed farmlands currently remove and sequester billions of tons of carbon dioxide from the atmosphere each year via photosynthesis. Exactly how many billions is up for debate. The University of Oxford study says that terrestrial ecosystems currently remove 2 billion tons of C02 a year and estimates that this number could double to 4 billion by 2050. But that’s below the low end of potential removal estimates cited in the Intergovernmental Panel on Climate Change, which predicts that terrestrial ecosystems could eliminate roughly 5 billion to 8 billion tons of CO2 from the atmosphere per year by 2050, simply with improved land stewardship practices.
Trees and crops perform a kind of lemons-to-lemonade climatic miracle as they breathe in carbon dioxide through their leaves and funnel it not only into useful materials such as corn, cotton and wood, but also through their roots into the ground, where carbon becomes the lifeblood of fertile soil.
Gregory Nemet, a co-author of the “State of Carbon Dioxide Removal” report and a public policy professor at University of Wisconsin at Madison, told me that pretty much all successful CO2 removal to date has come from natural climate solutions like protecting forests, planting trees and better managing soils. So I asked him, “Why not invest heavily in that?” To my mind, supporting and expanding the extraordinary potential of natural ecosystems to perform carbon removal is what investors and policymakers should be focusing on — not fantastical machines.
A premise of the report, Nemet said, is that “there’s a limit to what nature-based climate solutions can do.” But I see that limitation as a failure of creative thinking.
For one, it assumes that we’ll stick with current land-use patterns, which are heavily skewed toward agriculture: Farmlands currently cover well over half of the United States and about 40% of global land surface. The vast majority of those lands are dedicated to grain and conventional livestock production. But a combination of new technologies and policies can make it possible to grow more food on far less land. And land liberated from agricultural usage can be re-wilded and reforested — thereby turning billions of tons of carbon pollution into living ecosystems.
There’s no question that better management of forests and farmland can substantially reduce our atmospheric warming even within the next decade — and, further, that exponentially more carbon can be removed from the atmosphere if we invest in technologies that support and extend the power of nature. (Disclosure: My brother Bronson Griscom co-wrote a major study on natural climate solutions and leads ongoing research in this area for Conservation International.)
The biggest challenge with these natural solutions is that they are delivered by a complex set of ecosystems spread across the earth. It’s crucial to develop low-cost monitoring technology so this vast network can be measured and managed. Remote surveillance systems including satellite and radar that can track changes in land use with increasing detail can go a long way to help, as can devices that attach to trees to monitor rates of carbon sequestration.
Investors and policymakers should also support the development of microfinance systems that can reward populations with the richest forests — mostly in the equatorial nations — for the sustainable management of these essential carbon sinks. Some will be compensated for not cutting down trees. Others will be paid to sustainably manage agroforestry operations and to harvest trees in a way that benefits the long-term health of the forest. This would be a system far more sophisticated than PayPal, one with software that monitors and evaluates complex indicators of ecosystemic health and delivers payments accordingly via cellphones carried by farmers and forest managers in the field.
Above all, we need investment in climate-smart agriculture technologies from AI tractors and robotic weeders to vertical farms, GMO and CRISPR crops designed to withstand increasingly stressed growing conditions. I also have great confidence in the shift toward regenerative farming practices that can substantially increase both fertility and the capacity to sequester carbon dioxide in the earth’s soils. And there’s tremendous potential to shift land-use patterns on a grand scale through the creation and adoption of demand-side technologies — most notably meat alternatives such as plant-based products and cultured meats that require dramatically less land for the production of high-quality proteins.
Let me be clear that I’m not opposed to the more far-off technologies espoused in the University of Oxford report. Some important recent progress has been made by the Swiss company Climeworks, for example, and the Canadian company Carbon Engineering in the development of machines that function like giant C02 vacuums. In the long term we need all the solutions we can get, from machines and nature alike.
But our climatic clock is ticking, and right now we must focus our energy and investment on the most expedient path. For a long time, climate advocates resisted the discussion of carbon dioxide removal for fear it would distract from the urgent need to mitigate emissions. We certainly can’t let polluting industries off the hook. But we can’t ignore the importance of carbon removal any longer. Nor should we put too much emphasis, near term, on carbon-sucking machines.
The path forward requires humility. And if climate change has taught us anything, it’s that nature is a whole lot smarter and more powerful than we are. It’s time we acknowledge that the killer app of carbon dioxide removal is Mother Nature. Let’s invest in her.
More From Other Writers at Bloomberg Opinion:
• Cities Would Literally Be Cooler With More Trees: Lara Williams
• Global Warming Tests California’s Innovative Spirit: Faye Flam
• How Will Geoengineering Work? Look to Game Theory: Tyler Cowen
This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.
Amanda Little is a Bloomberg Opinion columnist covering agriculture and climate. She is a professor of journalism and science writing at Vanderbilt University and author of “The Fate of Food: What We’ll Eat in a Bigger, Hotter, Smarter World.”
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