Climate-Academy

Schlagwort: Forestry

  • Limited leeway: How much forest China can realistically reforest

    Limited leeway: How much forest China can realistically reforest

    Study assesses the real reforestation potential

    China relies in part on reforestation to reach its goal of climate neutrality by 2060. A new model analysis, based on global land-use data, four socioeconomic pathways (SSPs) and the dynamic vegetation model LPJ-GUESS, estimates how much new forest can realistically be established under existing political and ecological constraints—and what that means for climate and the economy.

    From theoretical to practical land potential

    Theoretically suitable areas for additional forest add up to between 111.4 and 118.4 million hectares depending on the scenario. After applying conservation constraints—including ecoregion rules (30.0 to 34.6 million hectares) and laws protecting agricultural land (3.5 to 11.4 million hectares)—the remaining practical area is 70.1 to 81.0 million hectares. This could raise China’s total forest area by 2100 to roughly 309.5 to 340.0 million hectares.

    Climate impact: increase yes, but limited

    Without additional afforestation, land-based carbon storage increases by 4.86 to 9.59 petagrams of carbon (PgC) by 2100. Reforestation raises that figure only moderately, adding another 0.48 to 2.82 PgC. The contribution is positive but limited compared with the emissions reductions needed to meet climate targets.

    Costs, revenues and distributional conflicts

    Using a social discount rate of 2 percent, the study estimates implementation costs of USD 97.5 to 139.3 billion. Far heavier are the opportunity costs from land competition and shifts in land use: USD 839.9 to 1,198.8 billion. Expected revenues from timber products amount to USD 903.8 to 976.4 billion, and social carbon benefits range from USD 468.7 to 2,739.4 billion. In the overall accounting, reforestation can be economically justified—depending on assumptions and regional implementation. However, because high-quality sites are often protected or used for agriculture, new plantings shift to less suitable regions, reducing efficiency and increasing local burdens.

    Land-use conflicts and regional imbalances

    Competition for land—with livestock grazing and cropland, for example—drives up opportunity costs and affects rural households. On marginal sites, carbon storage per hectare is lower and the climate benefit per unit area declines.

    Implications for policy and practice

    Reforestation remains a component of climate strategy but is not a cure-all. According to the study, what is needed includes: – targeted financial incentives that reflect regional differences and higher costs in marginal areas, – optimized forest management to increase carbon uptake per hectare, – integrated planning that accounts for food security and biodiversity protection.

    Financing and implementation

    Differentiated support mechanisms rather than blanket programmes can reward co-benefits such as biodiversity. Investments in management, maintenance and value chains for wood products can strengthen local incomes. International financing can help cushion high upfront costs and opportunity losses in economically weaker regions.

    Assessment

    China has substantial land reserves, but conservation rules, agricultural priorities and ecological limits constrain practical implementation. The additional carbon sequestration from reforestation remains modest. The central levers for meeting climate goals continue to be rapid emissions reductions in the energy and industry sectors; reforestation can complement those efforts if it is socially equitable and efficiently designed.

  • Satellites show: Europe’s forests have lost significantly more biomass since 2018

    Satellites show: Europe’s forests have lost significantly more biomass since 2018

    Since 2018 Europe’s forests have experienced considerably stronger biomass losses than previously assumed. Current analyses of Earth observation data point to this trend. Affected areas include not only weakened or young stands but also old, previously stable forests. The decline in woody biomass — in trunks, branches and roots — reduces forests’ CO2 uptake capacity and can release stored carbon back into the atmosphere.

    What the data show

    Spatially consistent analyses indicate a new pattern of large-scale losses since 2018 that cannot be explained solely by regular management. In several regions, damage has become more frequent and extensive, visible as reduced stand densities and sparser crowns.

    How remote sensing measures it

    Modern satellites combine radar, lidar and multispectral measurements. From these signals, woody biomass can be estimated across large areas and compared over years. Long-term, wall-to-wall observation makes it possible to rapidly identify trends and hotspots — independently of local inventory cycles.

    Drivers: drought and pests

    Prolonged dry periods weaken trees’ defenses. Insect pests such as bark beetles simultaneously benefit from warm, dry winters and longer growing seasons. Disturbances often overlap: drought facilitates infestations, the resulting canopy gaps dry out further and become more susceptible to erosion and structural shifts. Such cascades produce nonlinear damage — the combined effect of multiple stressors exceeds each one individually.

    Why old forests suffer particularly

    Older stands store large amounts of woody biomass but react sensitively to sudden water shortages. Historically shaped, even‑aged structures increase vulnerability when extensive areas reach advanced age at the same time. Conditions are aggravated on sites with shallow soils or at mountain margins, where persistent drought depletes soil moisture. Pure non‑intervention does not reliably protect everywhere under changed climatic conditions.

    Consequences for climate, economy and biodiversity

    As biomass declines, net carbon uptake falls. Locally, forests can temporarily become carbon sources when dying wood decomposes. For the timber sector this means lower predictable harvest volumes alongside more damaged timber — a combination that strains quality, logistics and profitability. Ecologically, structure, light regimes and species composition change: some species may benefit in the short term from increased deadwood, others lose habitat; in the long term, there is a risk of losing stable, species‑rich forest communities.

    What to do now

    Satellite‑based monitoring serves as an early warning system and should be linked with targeted field inventories. Adaptation strategies include structurally diverse mixed stands, regeneration with heat‑ and drought‑tolerant species and soil management measures to improve water retention. Where damage is severe, interventions are warranted: site‑adapted reforestation, selective removal of diseased trees and effective, ecologically sound protection against pest insects. At the same time, the sector needs flexible supply chains and methods to use damaged timber while limiting ecological risks.

    Adjusting policy

    Continuous Earth observation combined with local inventories provides the data base needed to set priorities: which stands are chronically affected, where are short‑term measures required? Support instruments for climate‑resilient management, stand diversification and assistance for adaptation measures gain importance. Europe’s forests remain central actors in climate protection — their role as carbon stores must, however, be actively secured.