Aligning intermediate climate targets with long-term decarbonisation ambition

The new submission round of Nationally Determined Contributions (NDCs) under the Paris Agreement presents a critical opportunity to enhance the credibility and feasibility of national decarbonisation pathways. By better aligning mid- and long-term targets, countries can reduce inconsistencies in emissions trajectories and strengthen the foundation for achieving long-term goals. Drawing on the experience of the European Union’s 2030 and 2040 intermediate emission targets, we highlight key considerations for setting milestones towards mid-century net-zero goals.

Introduction

National climate targets underpin the collective foundation towards achieving the global long-term temperature stabilization goal of the Paris Agreement. Its signatories must communicate successively more ambitious mid-term targets within NDCs, as well as long-term decarbonisation strategies (LTS). In the established 5-year updating cycle, the next wave of NDCs setting targets for 2035 is under preparation ahead of COP30 in 2025 in Brazil. This update from existing targets for 2030 offers an opportunity to better align NDCs with the most ambitious goals of the Paris Agreement, reducing their prevailing ambition gap¹. At the same time, it offers an opportunity to better align emission trajectories with countries’ net-zero targets, which show a lower ambition gap by mid-century and whose achievement could limit global mean temperature increase to below 2 °C². The misalignment between NDCs and LTS results in steeper emission reductions post 2030, raising questions on the consistency and feasibility of such emission trajectories (see Fig. 1A, portraying emission pathways by income groups and corresponding countries under an existing 2030 NDC and mid-century LTS targets trajectory).

Fig. 1: Modelled emission pathways reaching intermediate and long-term decarbonisation targets.

A Global emission pathway under 2030 NDC and LTS targets by income levels. Bold lines present global and income-groups’ emission trajectories, assuming full achievement of 2030 NDC and mid-century LTS targets. Thin lines present individual countries and major regions, covering a total of 43 regions representing the whole world. See ref. ²¹ for a comprehensive list of considered targets, regions and scenario rationale. Dots represent emission levels in 2035 compatible with long-term targets. B Decadal emission reductions by main strategies to decarbonise at global level. C EU emission pathway under existing and recommended 2030, 2040 and 2050 targets based on ref. ⁸. D Decadal emission reduction by sectors at EU level. Sources: A and B own elaboration after ref. ²¹; C and D own elaboration after ref. ⁸.

Treating updated NDC targets as milestones towards countries’ mid-century decarbonisation targets presents an important opportunity to improving the consistency of emission pathways. To align with its 2050 carbon neutrality goal, in 2021, the European Union revised its emission reduction ambition for 2030 from 40% to 55% below 1990 levels³, and the European Commission recently recommended reducing 2040 emissions by 90% compared to 1990 levels⁴ (see Fig. 1C, portraying the EU’s emission pathway under its existing 2030, recommended 2040 and its legislated 2050 decarbonisation targets). Drawing on key elements in this process, we discuss how 2030 and 2040 targets were treated as intermediate targets alongside a comprehensive sectoral roadmap towards the 2050 EU’s net-zero target. We highlight the main opportunities, challenges and policy design considerations that must play an important role in the decade after the current NDC targets.

A roadmap towards net-zero targets

Achieving net-zero targets will require all sectors to effectively decarbonise⁵. Context-specific roadmaps towards mid-century net-zero targets covering all sectors throughout the trajectory are crucial for understanding sectoral and temporal interplays and trade-offs, e.g. between the electricity decarbonisation and electrification, residual emissions and carbon sinks, front- or back-loading emission reductions. To date, most decarbonisation efforts have been realized in the power sector of highly developed countries, while important emerging economies are progressively deploying higher shares of renewable power capacities⁶.

At the global level, sectoral priorities differ across timeframes (see Fig. 1B, showing absolute decadal emission reductions at the global level, and the corresponding relative share of emission reductions by main strategies). A rapid decarbonisation of electricity generation is essential in the current and next decade. During the 2030 s, strong progress in electrification of end-uses will be crucial to decarbonise the transport, buildings and industry sectors. At the same time, maturing key technologies, and establishing markets and regulations will be essential for meaningful progress in the decarbonisation of hard-to-abate (H2A) sectors and carbon-dioxide-removals (CDR) technologies. This will allow large-scale deployment of key technologies like green hydrogen, e-fuels, carbon capture and storage, or direct air capture in the 2040s, to address hard-to-abate and residual emissions from e.g. industrial processes, agriculture, or international transport.

At country or regional level, the contributions of different abatement options may vary. For the EU, a pathway following the intermediate targets mentioned above shows similar characteristics as the global level (Fig. 1C, D), highlighting again that all sectors need to reduce emissions. Towards 2030, the energy supply and buildings sectors show the greatest potential for emission abatement, while advancements in renewable electricity integration and electrification also drive decarbonisation across all sectors^3,7. Assessing different trajectories with varying 2040 ambition levels, the European Commission concludes that early embarking on emission reductions will be crucial in sectors characterized by long lead times for innovation and infrastructure lifetime (e.g. steel, aluminium, chemicals, or cement), and whose decarbonisation will depend on the commercialization of novel technologies like green hydrogen or carbon capture and storage. Failing to early innovate and integrate H2A and CDR technologies otherwise risks an unfeasibly steep emission reduction trajectory in the 2040s^8,9.

Success factors for setting ambitious and feasible intermediate targets

Setting NDCs that bridge the ambition towards net-zero targets requires a thorough analysis of mitigation pathways. To avoid misalignment with mid-century targets, assessments for a new NDC need to look at the scenario space not only for the next decade, but the time horizon that covers the entire trajectory to a net-zero target. A sound quantitative modelling framework is essential to support this process, ensuring that pathways toward net-zero are internally consistent.

Importantly, modelling assessments should go beyond the technical feasibility of emissions reductions, and address the multiple and partly competing goals of energy policy, commonly described as the energy trilemma: sustainability, security of supply, and affordability. Modelling frameworks that are well suited to account for the sustainability and security of supply dimensions, must be expanded to assess the affordability implications for households and industries. Beyond energy policy, modelling can also account for multiple other relevant dimensions, including co-benefits such as air pollution and health. The European Commission’s 2040 target impact assessment integrates multiple energy and economic models⁸. Connecting models in a toolbox approach can ensure that, beyond technological feasibility, direct and indirect economic costs and benefits, as well as social implications are considered¹⁰.

Independent scientific advisory bodies have emerged world-wide as an important pillar of climate governance¹¹. In the EU, the European Scientific Advisory Board on Climate Change (EASBCC) was established in the 2021 European Climate Law as an independent body to provide scientific advice, ensuring overall consistency of EU policies with the Paris Agreement. It was mandated to support the setting of the 2040 intermediate target and provide an indicative EU-wide greenhouse gas budget for 2030–2050, and to monitor the decarbonisation progress. The 90–95% range of emission reductions by 2040 and the GHG budget recommended by the ESABCC served as key benchmarks for assessing the feasibility of the recommended 2040 climate target, including cost implications, technological deployment, and trade-offs^12,13. By providing multiple lines of evidence to support target-setting, scientific bodies can be effective in improving ambition and climate performance¹¹.

Success factors for delivering ambitious intermediate targets

Setting ambitious mid-term targets is only meaningful if their delivery is politically and socially viable. This requires adequate policy frameworks across all key objectives of energy policy¹⁴ — sustainability, security of supply, and affordability — to manage trade-offs and safeguard public and political support for the transition. For countries at earlier stages of their low-carbon transition, a regulatory framework that enables the integration of renewable and low-carbon technologies may still need to be established¹⁵. In the EU, a mix of policy measures was introduced with the Fit-for-55 package to deliver on 2030 target¹⁶; these policies will need to be updated to deliver on targets beyond 2030⁴.

Mobilizing capital will be essential to deliver on the substantial low-carbon investments with long capital lifetime required in a pathway to climate neutrality. This will improve the sustainability and resilience of the future energy system. To provide clear signals for investors and avoid stranded assets in fossil-infrastructure, stable political and regulatory frameworks are essential. The European Climate law established the legally binding commitment to the EU of achieving mid-century climate neutrality and an intermediate 2030 target (and will be amended for a 2040 target)¹⁷. Absence of firm political commitment to carbon neutrality might otherwise risk delaying investments and incurring higher costs, in particular for industries with costlier emission abatement and exposed to global competition.

Maintaining the competitiveness of trade-exposed industries will be essential; adequate policy design therefore also needs to consider access to affordable energy^18,19. While the EU’s emission trading system (ETS) is the main instrument translating emission targets into price signals and hence concrete investment incentives, the policy mix is evolving. A carbon border adjustment mechanism (CBAM) was introduced to avoid carbon leakage and a larger innovation fund fed with ETS revenues will finance innovative technologies¹⁶. Further instruments like carbon contracts for difference are under discussion.

Ensuring affordability for households and managing social impacts will be critical as Europe transforms its economy to carbon neutrality. Clean technologies will create new employment opportunities, but require a scale-up of specific skills. At the same time, the decline in fossil-fuel related industries and carbon intensive technologies will lead to employment reduction, sometimes concentrated in particular regions. Beyond employment, the forthcoming expansion of EU carbon pricing to road transport and buildings will lead to new abatement incentives, but can negatively affect specific segments of the population, such as low-income households, private-mobility-reliant commuters or certain small businesses. A new EU Social Climate Fund will therefore complement the ETS expansion to ensure a fair transition¹⁶.

Role of science in the process

Science can provide guidance for robust interim targets to keep countries on track to reaching their committed net-zero targets. The modelling community can contribute realistic sectoral and economy-wide pathways, avoiding inconsistencies between intermediate and mid-century targets²⁰. This calls for holistic assessments, considering the technological, economic, social and political dimensions of ambitious decarbonisation trajectories. Despite common decarbonisation patterns and challenges ahead, context-specific assessments are essential to acknowledge specificities. The example of the EU suggests that thorough analysis can be an important building block for ambitious climate targets. Beyond target setting, science can also play a crucial role to inform the upcoming implementation phase. This will require designing updated policy frameworks that provide the right incentives for reaching the intermediate targets, monitoring target implementation, while ensuring social fairness, public support, and maintaining international competitiveness.