Long-term national climate strategies bet on forests and soils to reach net-zero

As net-zero becomes a central principle of climate policy, countries are beginning to consider the practical and policy dimensions of deploying carbon dioxide removal (CDR) to achieve national climate targets. Although 124 countries have agreed to net-zero emissions targets, CDR is rarely made explicit in policy plans. This study asks how CDR is integrated into long-term national climate strategies (LT-LEDS), what methods are prioritized, how residual emissions and removals are quantified, and what feasibility constraints and cooperation needs are identified. The purpose is to provide a systematic, comparative analysis of CDR in national planning, addressing the gap between global assessments and country-level deployment decisions. The study is important because CDR is needed to counterbalance residual emissions from hard-to-abate sectors and may require international transfers where national constraints limit domestic deployment.

Prior work has largely assessed CDR within global scenarios, debating the credibility, sustainability, and feasibility of large-scale deployment, and highlighting differences between nature-based and engineered methods in terms of cost, readiness, permanence, and social acceptability. Existing analyses of national strategies have focused on conceptual roles, governance, and feasibility assessment criteria, and have noted ambiguity in targets and limited explicit treatment of engineered CDR. NDCs tend to emphasize forest and soil carbon in the near term, with limited attention to engineered CDR. There is also an ongoing debate about terminology (natural vs technological) and about the role of CCUS as an adjacent consideration for scaling CDR. This study extends the literature by providing an updated, larger-sample comparative analysis of LT-LEDS, examining target clarity, method choice, quantified amounts, residual emissions, feasibility constraints, and international cooperation needs.

The authors analysed all LT-LEDS published in English by the UNFCCC Secretariat before January 1, 2022, plus Estonia’s EU long-term strategy, yielding 41 strategies out of 50 submitted (covering approximately 58% of global 2019 GHG emissions and ~74% of global GDP). The corpus comprised 3,885 pages. Using NVivo, they applied a mixed inductive–deductive coding approach. Categories covered CDR methods (nature-based: forests, soils, coastal blue carbon, enhanced weathering; engineered: BECCS and DACCS), quantification of CDR and residual emissions in 2050, qualitative or speculative advocacy of methods, long-term target definitions (sectoral and GHG coverage, treatment of international aviation/shipping, use of international offsets), feasibility considerations (biophysical, technological), and calls for international cooperation. Where strategies provided multiple scenarios, the scenario reflecting the stated national position or long-term target was used for quantification. Land sector status ('sink status') was recorded based on LULUCF (or AFOLU where necessary) as presented in each strategy for the most recent historic inventory year and 2050 projections. The heterogeneity of terminology (e.g., LULUCF vs specific CDR methods) was addressed by mapping to gross removals where possible or categorizing as undefined nature-based CDR when only aggregate values were provided. Policy instrument detail was generally too limited across strategies to support categorical analysis and was excluded.

- Sample and scope: 41 LT-LEDS analysed (English), covering ~58% of 2019 global GHG emissions and ~74% of global GDP. Most were published in 2020–2021, predominantly from the Global North. - Target clarity: Many strategies use inexact or ambiguous long-term targets (e.g., 'carbon neutrality' vs 'climate neutrality', unclear sector and GHG coverage, treatment of international aviation/shipping, and offsets). Only the UK and Switzerland explicitly include international aviation and shipping. - CDR advocacy and quantification by method: - Forest carbon enhancement: advocated in 40 strategies; explicitly quantified in 12. - Soil carbon: advocated in 30; quantified in 4 (Indonesia, Australia, France, Portugal). - Coastal blue carbon: advocated in 14; quantified in 1 (Fiji). - BECCS: advocated in 16; quantified in 5; primarily considered by Global North countries. - DACCS: advocated in 7; quantified in 2 (UK, Switzerland); exclusively considered by Global North countries. - CCUS (not CDR itself but adjacent): advocated in 31; quantified in 5. - Residual emissions: Quantified in 20 strategies. In 13 (USA, Indonesia, Thailand, France, Cambodia, Sweden, Finland, Portugal, North Macedonia, Slovakia, Costa Rica, Hungary, Slovenia), increased forest carbon or nature-based CDR is primarily or solely relied upon to counterbalance residual emissions by mid-century. The UK is notably dependent on BECCS; Switzerland splits between BECCS and DACCS. - Integration challenges: Many strategies do not quantify residual emissions or the requisite CDR, limiting comparability. Countries appear to struggle to integrate CDR into modelled scenarios grounded in national GHG inventories that are not designed for CDR accounting. - Feasibility constraints identified: - Nature-based CDR: Risks from reversibility, disturbances (wildfire, pests, disease), saturation of forests and soils, uncertainties in estimates. Several countries (e.g., South Korea, Slovakia, Ukraine, Hungary, Finland) anticipate limited forest sink contributions due to mature stands or limited land; others note vulnerability to natural hazards (Portugal, Sweden, Slovenia). Soil carbon saturation and climate impacts on soil storage effectiveness are noted (France, Malta). - Engineered-CDR: Constraints from limited or absent national geological storage capacity (Austria, Switzerland limited; Singapore none), siting issues (Cambodia), infrastructure build-out rates, energy needs, and social acceptability. France reports initial potential up to ~1.5 GtCO2 of storage with suitable source–sink co-location but notes social acceptability may favour offshore storage. - Cooperation needs: Multiple strategies call for international cooperation and transfers. Examples include Netherlands and Switzerland envisaging partnerships for CO2 storage (e.g., North Sea), and Australia proposing high-integrity carbon markets in the Indo-Pacific, potentially mobilizing soil carbon as offsets. Such transfers would rely on robust rules under Article 6 and raise questions about domestic net-zero when contingent on ex-situ CDR.

The analysis demonstrates that while most countries acknowledge the need for CDR to achieve net-zero, national LT-LEDS frequently lack precise target definitions and robust quantification of residual emissions and removals. This ambiguity obscures CDR demand, influences method portfolios, and risks locking out options. The heavy reliance on forests and soils is understandable given policy legacy and co-benefits, yet it is risky due to saturation, reversibility, and disturbance vulnerability, challenging the durability of national net-zero as an ongoing state. Engineered CDR can provide continual negative emissions but faces constraints related to geology, infrastructure, energy, and social acceptance; thus, international cooperation (e.g., cross-border storage, Article 6 transfers) may be necessary, particularly for countries with limited domestic storage or land availability. Strategies that quantify both residual emissions and CDR tend to recognize these constraints and articulate cooperation needs, underscoring the importance of explicit modelling, feasibility assessments, and governance frameworks. Strengthening UNFCCC guidance and requirements for LT-LEDS could improve transparency, comparability, and near-term policy alignment.

This study provides a systematic, comparative assessment of how CDR is incorporated into national long-term climate strategies. It shows widespread advocacy for enhancing forest and soil sinks, limited and uneven quantification of CDR and residual emissions, and emerging recognition of national constraints and international cooperation needs. The authors recommend making LT-LEDS (or similar) a compulsory UNFCCC reporting requirement with clear guidance: adopt a shared definition of national net-zero; specify GHG and sectoral coverage, treatment of international aviation/shipping, and the intended use of offsets; and support targets with modelled pathways that explicitly quantify residual emissions and the CDR portfolio. Countries should conduct feasibility assessments reflecting national circumstances and consider near-term incentives (e.g., negative emission targets in NDCs). Given permanence and capacity limits of nature-based CDR, national strategies should further engage with engineered CDR and potential Article 6 mechanisms, especially where domestic geological storage is limited. Future research and policy development should also expand feasibility analysis beyond biophysical and technological aspects to include socio-cultural and political dimensions and consider pathways to sustained net-zero and eventual net-negative emissions.

- Language and selection bias: Only strategies available in English were analysed; nine non-English strategies were excluded, and regions like Africa and Latin America are under-represented. - Temporal relevance: Some strategies are older (e.g., Germany, Canada) and may not reflect recent policy developments or updated targets. - Heterogeneity of documents: Strategies vary widely in depth, structure, terminology, and methodological detail, limiting comparability. - Accounting constraints: National GHG inventories and current guidelines are not designed for explicit CDR accounting, complicating integration and quantification in scenarios. - Policy detail: Treatment of specific policy instruments targeting CDR was generally too limited to categorize meaningfully and was excluded from analysis. - Aggregation issues: Use of LULUCF/AFOLU aggregates can obscure gross removals versus emissions (e.g., mixing LULUCF removals with agricultural non-CO2 emissions), affecting interpretation of land-sector contributions.