Long-Term Studies
Life cycle impacts of forest management and wood utilization on carbon mitigation: knowns and unknownsBackgroundForests currently remove 2-3 GtC yr⁻¹ from the atmosphere, while global wood harvest exceeds 3-4 billion m³ yr⁻¹, creating complex interactions between forest carbon stocks, harvested wood products, and the substitution of wood for more emission-intensive materials. Lifecycle assessment (LCA) is widely used to evaluate these interactions, but differing system boundaries, baselines, and treatment of carbon pools can lead to very different conclusions about mitigation benefits. Clarifying where evidence is robust and where major uncertainties remain is essential for designing coherent forest-climate policy. Open access copy available |
Forest carbon in Amazonia: the unrecognized contribution of indigenous territories and protected natural areasBackgroundAmazonia stores an estimated 80–120 Pg of aboveground carbon, and changes in this stock have global climate implications. Indigenous territories (ITs) and protected natural areas (PNAs) together cover roughly one-third to one-half of the Amazon region, yet their specific contribution to maintaining forest carbon has often been overlooked in regional mitigation discussions. Quantifying their role is important for designing REDD+, climate finance, and land rights policies that reflect on-the-ground conservation performance. Open access copy available |
Towards a modular multi ecosystem monitoring, reporting and verification (MRV) framework for soil organic carbon stock change assessmentBackgroundSoils store roughly 1,500–2,400 petagrams (Pg) of organic carbon globally, more than the combined carbon in the atmosphere and vegetation, making soil organic carbon (SOC) a critical component of climate mitigation and land degradation neutrality targets. Many initiatives assume that relatively small annual increases in SOC across large areas could offset gigatonnes (Gt) of CO2, but these claims require robust, comparable monitoring systems. Current MRV approaches often focus on single sectors and use heterogeneous methods, limiting their usefulness for cross-ecosystem accounting and results-based finance. Open access copy available |
Overestimated natural biological nitrogen fixation translates to an exaggerated CO2 fertilization effectBackgroundBiological nitrogen fixation (BNF) supplies a substantial fraction of reactive nitrogen of ecosystems, typically estimated in the tens to over 100 Tg N yr⁻¹ globally, thus constraining how strongly plants can respond to rising CO2. Many Earth system models (ESMs) parameterize BNF such that nitrogen does not strongly limit CO2 fertilization, potentially inflating modelled land carbon sinks and underestimating future atmospheric CO2 concentrations. Quantifying this bias is important for realistic carbon budget and mitigation assessments. Open access copy available |
Emerging climate impact on carbon sinks in a consolidated carbon budgetBackgroundOpen access copy available |
Enhancing climate change mitigation in protected areasBackgroundProtected areas (PAs) cover roughly 15–17% of the Earth’s land surface and contain a large share of remaining intact ecosystems, many of which store high densities of carbon. With global terrestrial ecosystems absorbing about 3 GtC yr⁻¹, understanding how much of this sink is associated with PAs is important for integrating biodiversity and climate strategies. However, evidence on PA effectiveness for carbon protection, across thousands of sites and multiple biomes, is dispersed and unevenly synthesized. Open access copy available |
Aboveground and belowground tree biomass and carbon stocks in the miombo woodlands of the Copperbelt in ZambiaBackgroundMiombo Woodlands occupy an estimated 2.7 million km² across southern Africa and support millions of people through fuelwood, charcoal, and non-timber products, while also storing substantial carbon. In Zambia’s Copperbelt Province, woodland conversion and degradation for charcoal and agriculture risk reducing carbon stocks, but local biomass values are poorly constrained, leading to uncertainty in national estimates and REDD+ baselines. This study responds to the need for site-specific biomass and carbon data in one of Zambia’s most industrialized and heavily used miombo regions. Open access copy available |
Global Carbon Budget 2023Background“Global Carbon Budget 2023” extends this annual budget series with data up to 2022 and a projection for 2023, including for the first time explicit treatment of carbon dioxide removal (CDR) and new constraints from atmospheric oxygen measurements. Atmospheric CO2 averages 417.1 ± 0.1 ppm in 2022 and is projected to reach about 419.3 ppm in 2023, reflecting continued net accumulation despite temporary pandemic-related emission reductions. Open access copy available |
Global Carbon Budget 2022Background“Global Carbon Budget 2022” extends the series of budgets to 2021 with a projection for 2022, documenting that fossil carbon dioxide (CO2) emissions likely surpass pre-COVID pandemic levels. Atmospheric CO2 growth remains high, with decadal mean growth around 5.2 GtC yr⁻¹ for 2012-2021 and concentrations exceeding 414 ppm. Open access copy available |
Global Carbon Budget 2021Background“Global Carbon Budget 2021” updates the budget to 2020 and projects 2021, analyzing the rebound of carbon dioxide (CO2) emissions after the initial downturn during the COVID-19 pandemic. Atmospheric CO2 continues to increase, with decadal mean growth reaching ~5.1 GtC yr⁻¹ for 2011–2020 and concentrations surpassing 412 ppm. Open access copy available |
