A recent study published in Nature suggests that the restoration and protection of forests worldwide could remove approximately 226 gigatons of carbon from the atmosphere. This figure is equivalent to roughly 20 years of emissions from burning fossil fuels at current rates. The study provides a more reliable estimate compared to a previous controversial analysis that only considered the potential benefit of restoring trees to degraded land. Experts believe that the findings offer clarity and confidence regarding the significant role of forests in combating the climate crisis. However, some critics question the achievability of the new estimate.
The research indicates that although uncertainty remains about the precise amount of carbon forests can absorb, the evidence is strong enough to warrant action in planting, restoring, and safeguarding forests. Nevertheless, certain experts, like ecologist Joseph Veldman from Texas A&M University, express skepticism towards the study’s numbers. Veldman argues that much of the carbon benefit would come from planting trees in ecosystems like grasslands, where they don’t naturally belong, posing a threat to biodiversity.
The study builds upon earlier research from 2019, which estimated that 205 gigatons of carbon could be sequestered through forest restoration across a vast area of land. However, that study faced criticism for assuming an overly high carbon capture rate per hectare of forest. In contrast, the new study by Thomas Crowther’s group employed satellite and ground-based data, using machine-learning models to estimate global forest carbon. The convergence of findings from these two methods increases confidence in the estimate.
The study also highlights the potential carbon storage capacity of mature forests, including not just trees but also dead wood, leaves, roots, and soil. Protecting existing forests from logging could result in the absorption of 138 gigatons of carbon. Additionally, restoring tree cover to areas where it once existed could capture another 88 gigatons of carbon, although significantly lower than the 2019 estimate.
The authors acknowledge that the demand for timber and wood products will limit the carbon uptake potential of forests. They emphasize that they do not advocate for eliminating timber use but rather highlight the full potential of forests in carbon capture.