China has planted trees on an unprecedented scale. Between 1990 and 2020, its forests expanded from 157 to 220 million hectares, a gain of 63 million hectares in three decades. According to Yao et al., a planting and densification scenario involving 4.47 billion trees would allow for storage of 5.9 ± 0.5 PgC. Growth rate and net absorption vary depending on species, stand structure, climate, disturbances, and management.
The Essentials
- Chinese forests expanded by 63 Mha between 1990 and 2020, bringing total stock to 220 Mha (Chinese National Forestry Inventory).
- Sequestration potential is estimated at 5.9 ± 0.5 PgC by 2060, but with an expected plateau after 2040 as stands age (Nature Communications, 2024).
- Carbon yield per tree declines after 20 to 30 years: biology imposes a limit that investment alone cannot push back.
- 87% of Chinese voluntary carbon credits from afforestation present a risk of being non-additional, according to Nature npj Climate Action (2026).
- Depletion of plantable land before 2050 transforms an expansion strategy into a management strategy, a regime change that neither centralized planning nor public funding had anticipated.
Sixty-Three Million Hectares in Thirty Years
Land suitable for afforestation remains limited.
China’s afforestation program ranks among the most ambitious environmental projects of the twentieth and twenty-first centuries. Launched in 1978, the program known as the “Great Green Wall” aimed primarily to combat desertification and erosion; its plantations also contribute to CO₂ absorption. The Chinese National Forest Inventory, conducted in four successive phases, documents this progression: the gain of approximately 63 million hectares comes from an FAO dataset compiled from national inventories and including interpolations.
This result carries considerable political and financial costs. Millions of farmers have been relocated or had their practices transformed. Billions of yuan have been invested over several decades. The state mobilized its administrative apparatus from the national level down to villages. In terms of the ability to concentrate resources on an environmental objective, China did what few liberal democracies would have been capable of organizing at that speed.
The gross climate result is real. 220 million hectares of forests in 2020, with an increasing share of plantations, constitute a significant terrestrial carbon stock. Yu et al. project a biomass stock of 21.6 to 24.3 Pg C in 2100, or 79 to 89 GtCO₂ in CO₂ equivalent of carbon content, and not a potential of 21.6 GtCO₂. The projected cumulative sink from 2020 to 2100 is 11.2 to 14.8 Pg C, or approximately 41 to 54 GtCO₂.
Operational technological capacities for carbon capture are not directly comparable to the projected carbon stock for this forest scenario.
But this figure warrants closer reading.
The Limits That the Growth Curve Conceals
A young tree grows quickly. It captures CO₂ at a high rate, converts light into woody biomass, extends its roots. Growth rate varies depending on species, stand structure, climate, disturbances, and management. Carbon stock continues to increase, but more slowly. Old forests may remain net sinks or become sources depending on climate, disturbances, mortality, and management; age alone does not establish a universal equilibrium point.
This biological mechanism is not a recent discovery. Foresters have known about it for a long time. What is new is its interaction with the climate agenda. China planted massively beginning in the 1980s and 1990s. Those trees are now twenty to forty years old.
The future dynamics of sequestration will depend in particular on stand age, their management, and disturbances.
Nature Communications (Yu et al., 2024) projects that forest biomass carbon stock will plateau as trees age, leading to a decline in the sink; Yu et al. situate the peak of the forest carbon sink during the 2020-2040 decades according to their statistical model and in the 2050s according to the biogeochemical model based on processes (DLEM). This projected forest peak likely occurs after the official Chinese peak target, set before 2030; the effective peak date remains a distinct empirical question.
There is a simple arithmetic tension here. If forests sequester less at precisely the moment when emissions remain high, the margin for climate maneuver shrinks. Afforestation is not thereby negated—the planted trees continue to store carbon—but the dynamic changes in nature. Managing an existing stock is not the same as creating a new one.
Money Cannot Plant Where There Is No More Land
The second constraint is geographic. Land suitable for afforestation in China—uncultivated soils, non-desert, with sufficient rainfall—is limited. Studies identify strong limits to afforestation potential, but do not conclude that it is largely exhausted before 2050. Historical plantations on unsuitable sites have experienced low survival rates; no evidence provided shows that current programs are systematically performing worse than the first waves.
This limit is qualitatively different from a lack of financing. It cannot be resolved by additional budget. A state can decide to plant an extra ten billion trees, but it cannot decree that sufficient suitable land exists. The physical constraint is a frontier that centralized planning cannot cross.
In debates on industrial decarbonization, particularly those opened by transition finance practitioners such as Benjamin Fremaux, who works on investments necessary for decarbonizing buildings and heating networks, the dominant question concerns the financing deficit: where to find the capital to build necessary infrastructure. Chinese afforestation illustrates a different trajectory: capital has been mobilized and the state has invested.
Biophysical and land constraints limit potential, but that potential also depends on management choices, densification, location, and survival.
This shift deserves to be taken seriously for what it reveals about climate strategies in general. Decarbonization based on biological compensation, planting to offset what is emitted, assumes that sequestration capacity grows in parallel with emissions. Yet biology does not follow the timelines of ministries. It follows its own cycles.
The Voluntary Carbon Market Faces Its Own Numbers
The third tension is that of carbon credit credibility. Published on February 27, 2026, the article reports that an external study found a high risk of non-additionalness or low integrity for 87% of offsets in corporate portfolios; this is neither a Chinese sample nor specifically afforestation. Certain forest compensations may present additionalness risks. No examined source allows us to assert that foreign company compensation rests largely on Chinese forests that would have existed anyway.
This finding does not discredit Chinese afforestation as such. Trees actually absorb carbon. But it poses a problem of climate accounting. If carbon credits sold on voluntary markets do not correspond to additional absorption, the emissions they are supposed to offset remain in the atmosphere. The buyer has settled their accounting debt; the physical debt remains.
This problem of additionalness in compensation markets affects the entire voluntary market, from REDD+ credits in the Amazon to energy efficiency projects in Africa. The Chinese case illustrates with particular clarity the gap between the physical ambition of a program and its translation into financial instruments. A program can be real and its credits poorly calibrated simultaneously.
Regulation of the Chinese voluntary carbon market, like that of the developing ETS market, will need to resolve this tension if afforestation is to effectively serve as a price signal for industrial decarbonization. Without this rigor, the risk is that emitting sectors purchase accounting comfort that physics does not grant them.
The Impact of the 2040-2060 Period on Climate Calculation
Beijing’s stated objective of carbon neutrality is set for 2060. The contribution of Chinese forests to offsetting residual emissions will depend on their management, climate, disturbances, and the pace of emissions reduction.
Two trajectories can be envisioned. In the SSP1-2.6 scenario with continued afforestation, neutrality requires substantial reduction in energy and industrial emissions; land removals compensate only a fraction of residual emissions, while their potential eventually plateaus then declines. This trajectory presumes industrial and energy decarbonization at an unprecedented pace between 2030 and 2050; the acceleration of Chinese renewables provides arguments for this scenario, but emissions from the construction and heavy industry sectors remain a considerable unknown.
In another trajectory, emissions could remain high despite committed reductions. Depending on trajectories adopted, a deficit could emerge if reductions and sinks were insufficient. China might need to accelerate reduction of residual emissions and develop sinks and CCUS; CCUS already exists at industrial scale, but remains limited at the scale necessary for national neutrality.
The distinction between these two trajectories depends less on forest management itself than on the speed of decarbonization in fossil sectors. This link is at the heart of the problem: a climate strategy that relies on biological sequestration as a safety net assumes that net holds when needed. Yet the net has a biological expiration date.
There is a broader lesson for the climate strategies of all countries that bet on forests and nature in their nationally determined contributions. Biological carbon absorption is real, measurable, and precious. But it obeys temporal and spatial dynamics of its own, which do not automatically align with the horizons of climate agreements. Regenerative agriculture poses the same question at another scale: carbon storage practices in soils have ceilings, lag times, application conditions that cannot be decreed.
Managing What Is There Rather Than Planting What Is Missing
The regime change that Chinese afforestation approaches, from expansion to management, compels a reformulation of priorities. Planting is a visible action, measurable, politically valorizable. Managing an existing forest to maximize its resilience to fires, droughts, and pests is less notable, but determining for maintaining accumulated carbon stock.
Forest inventories and statistics, supplemented by data on fires, pests, and diseases, document the existence of real risks of forest loss. Forest fires and droughts pose risks to Chinese forests. Monospecific plantations, planted in waves with the same species for yield reasons, are more vulnerable to pest epidemics than mixed natural forests. A fire or dieback can re-emit a substantial portion of previously fixed carbon and reduce or temporarily reverse the sink, but it does not necessarily return all absorbed carbon to the atmosphere.
Forest management as a climate tool requires different investments: species diversification, health risk monitoring, maintenance of ecological connectivity, adaptation to precipitation change projections. These investments follow different logic than massive afforestation: they are diffuse, continuous, difficult to attribute to a discrete project. Carbon credit mechanisms can remunerate both afforestation or reforestation and certain forms of conservation or improved forest management; a comparison of their effective valuation would require precise market data and methodologies.
This is one of the structural adjustments that carbon markets and forest policies will need to negotiate over the next fifteen years. The price signal must reward preservation as much as creation. If only carbon sequestered in new trees is valued, incentives push toward planting where possible rather than protecting what is there. Yet as available land depletes, this incentive displacement becomes an increasingly costly design error.
Neither forest inventories nor growth models can alone settle the following question: to what extent will the biological ceiling of afforestation modify the carbon neutrality ambitions of major emitters. Chinese decision-makers, like their counterparts elsewhere, will need to choose when to explicitly integrate this ceiling into their trajectories, rather than letting it appear as a shortfall in 2050 accounts.
Sources
- Chen et al., China’s forest carbon sequestration potential and uncertainty, Nature Communications, September 2024, https://www.nature.com/articles/s41467-024-54846-2
- Nature npj Climate Action, Additionality risk in Chinese voluntary carbon credits from afforestation, February 2026, https://www.nature.com/articles/s44168-026-00350-w
- Chinese National Forestry Inventory, four phases documented (1990–2020), National Forestry and Grassland Administration of China
- Benjamin Fremaux, work on financing thermal decarbonization and the “finance-build-operate” model in building energy transition