- New research shows that a mix of natural forest regrowth and tree planting could remove up to 10 times more carbon at $20 per metric ton than previously estimated by the IPCC, the U.N.’s climate science panel.
- The study found that natural regeneration is more cost-effective in 46% of suitable areas, while tree planting is better in 54%, suggesting a tailored approach could maximize carbon capture.
- Researchers estimate that using the most cost-effective method in each location could remove 31.4 billion metric tons of CO2 over 30 years at less than $50 per metric ton.
- While the findings are promising, experts caution that reforestation alone can’t solve the climate crisis and emphasize the need to consider biodiversity and other ecological factors alongside cost-effectiveness.
Trees are allies in the struggle against climate change, and regrowing forests to capture carbon may be cheaper than we thought. According to new research published in Nature Climate Change, a strategic mix of natural regrowth and tree planting could be the most cost-effective way to capture carbon.
Researchers analyzed 138 reforestation projects in low- and middle-income countries to compare the costs of different reforestation approaches. They found it’s possible to remove 10 times more carbon at $20 per metric ton, and almost three times more at $50, compared to what the Intergovernmental Panel on Climate Change (IPCC) had previously estimated.
Neither natural regeneration nor tree planting consistently outperforms the other. Instead, the most cost-effective method varies depending on local conditions. Natural regeneration, which involves letting forests regrow on their own, is cheaper in about 46% of suitable areas. Tree planting, on the other hand, is more cost-effective in 54% of areas.
“Natural regeneration is more cost-effective in areas where tree planting is expensive, regrowing forests accumulate carbon more quickly, or timber infrastructure is distant,” said lead author Jonah Busch, who conducted the study while working for Conservation International. “On the other hand, plantations outperform in areas far from natural seed sources, or where more of the carbon from harvested wood is stored in long-lasting products.”
The research team estimates that by using the cheapest method in each location, we could remove a staggering 31.4 billion metric tons of carbon dioxide from the atmosphere over 30 years, at a cost of less than $50 per metric ton. This is about 40% more carbon removal than if only one method was used universally.
“It’s exciting that the opportunity for low-cost reforestation appears much more plentiful than previously thought; this suggests reforestation projects are worth a second look by communities that might have prejudged them to be cost prohibitive,” said Busch. “While reforestation can’t be the only solution to climate change, our findings suggest it should be a bigger piece of the puzzle than previously thought.”
To reach these conclusions, the research team gathered data from hundreds of reforestation projects and used machine-learning techniques to map costs across different areas at a 1-kilometer (0.6-mile) resolution.