Climate mitigation potential for targeted forestation after considering climate change, fires, and albedo
This week, we deep dive into a paper recently published in Science Advances. The study was led by Shijing Liang, affiliated with the School of Environmental Science and Engineering of the Southern University of Science and Technology in Shenzhen (China), and the Institute for Global Change Biology and the School for Environment and Sustainability of the University of Michigan, Ann Arbor (USA).
This paper presents a refined estimate of how much carbon could be sequestered globally between 2021 and 2100 if forestation efforts were targeted optimally – omitting areas with minimal mitigation effects – while accounting for climate feedbacks, fire disturbances, and surface albedo effects. The Earth system model simulations suggest a carbon mitigation potential of roughly 31.3 to 69.2 petagrams (Pg, where 1Pg = 1 billion tonnes) of carbon equivalent (or 114.8 to 253.9 Gt of CO2) under a sustainable socioeconomic pathway. Importantly, the gains are highly regionally variable, with tropical zones showing the greatest promise, while mid‐ to high‐latitude regions exhibit more nuance and risk. The study emphasizes that simplistic area-based planting targets may overestimate benefits if they neglect disturbances or albedo penalties. The authors argue that forestation planning must integrate dynamic climate risks, fire regimes, and surface reflectance tradeoffs for robust nature-based mitigation strategies.
One of the original contributions of this study is its integration of multiple, often neglected feedbacks and trade-offs into forestation potential assessments. Past satellite-based or bookkeeping estimates frequently assume static climate conditions, ignore the possibility of fire converting forests back into carbon sources, and do not account for how darker tree canopies could reduce surface reflectance (albedo) and thereby increase local warming. This work couples a full Earth system model with disturbance and radiative feedback modules, enabling more realistic simulations of how planted forests interact with evolving climate, fire risk, and surface energy balances. By doing so, the authors avoid the pitfall of overestimating carbon gains and bring forward a framework that more faithfully captures the complexity of nature-based mitigation. Moreover, the use of spatially explicit “suitable area” maps, which filter out environmentally sensitive lands and human-use conflicts, enhances projections’ practical value.
In terms of results, under a “sustainable shared socioeconomic pathway,” global forestation (afforestation + reforestation) could yield cumulative mitigation of 31.3 to 69.2 Pg carbon equivalent (Ceq) from 2021 to 2100. Regionally, tropical and subtropical regions dominate the carbon returns, owing to faster growth rates and lower fire risk, while in mid- and high- latitudes, the benefit is more heterogeneous—some areas suffer from albedo penalties or elevated fire risks, which can dampen or even negate net carbon gains. The authors find that inappropriate planting in high-latitude snow-covered or dry zones could reduce reflectance so much that warming offsets part of the carbon sequestration benefit. They also show that fire disturbances can erode carbon gains, especially under warming trends. Overall, the results underscore that the “right tree in the right place” is key: to maximize mitigation, forestation strategies should avoid regions with high disturbance or strong albedo trade-offs, and instead favor locations with high resilience, low fire hazard, and minimal reflective drawbacks.
Here is a list of the main takeaways of this paper:
- Global forestation may sequester ~31.3 to 69.2 Pg Ceq (114.8 to 253.9 Gt of CO2) between 2021 and 2100 if optimally targeted — much lower than naive estimates that omit other feedbacks, such as surface albedo effect.
- Tropical zones offer the highest carbon mitigation per area, due to fast growth and lower fire risk; mid/high latitudes are far more variable.
- Fire disturbance under climate change can reverse forestation gains, making long-term stability a critical factor.
- Albedo effects matter: planting in snow or high albedo regions can reduce surface reflectance so much that warming offsets carbon benefits.
- Effective mitigation requires spatial targeting and avoidance of sensitive lands or human-use conflicts — area metrics alone are insufficient.
Read the full paper here: Climate mitigation potential for targeted forestation after considering climate change, fires, and albedo