Better understanding and attribution of land and ocean carbon sources and sinks

The EU funding opportunity HORIZON-CL5, titled "Better Understanding and Attribution of Land and Ocean Carbon Sources and Sinks," is part of the Horizon Europe program. This call falls under the category of HORIZON Research and Innovation Actions (HORIZON-RIA) and utilizes lump sum grants. The application process is single-stage, with an opening date of November 17, 2026, and a deadline of March 4, 2027, at 17:00 Brussels time. The funding allocated for this initiative is a total of €25 million, which will be distributed across five projects, each receiving €5 million. The focus of this opportunity is on advancing fundamental climate science, addressing significant knowledge gaps identified by the Intergovernmental Panel on Climate Change (IPCC) concerning how terrestrial and oceanic ecosystems interact with carbon dioxide under varying climate conditions. Eligible applicants include research organizations, universities, public research institutions, and similar entities from EU Member States and Associated Countries. There are provisions for international cooperation, particularly with entities from low and middle-income countries. Projects must be consortium-based, emphasizing cooperation and coordination across different research areas. The grant aims to achieve better understanding and quantification of oceanic and terrestrial carbon fluxes, as well as reconcile differing estimates of CO2 emissions from land use. Proposals should focus on one of three areas: oceanic CO2 sources and sinks, land CO2 sources and sinks, or reconciliation of land use CO2 emission estimates. Coordination with other initiatives, such as the European Space Agency’s FutureEO program, is encouraged to enhance data accessibility and methodology. Expected outcomes include improved understanding of carbon cycling mechanisms, contributions to reconciling emissions estimates, and the promotion of consistent quantification of carbon transfers. The successful projects will need to follow open science principles, ensuring that developed tools and models are accessible. The evaluation process consists of a single-stage submission, including an assessment against specified criteria. While success rates are not explicitly stated, the competitive nature of the funding suggests a typical success rate of 10-39%. Co-funding is not required, but synergies with other funding programs are encouraged. The opportunity aligns with broader goals of supporting climate action and enhancing scientific capacity across Europe. This opportunity highlights the EU's commitment to advancing climate science and supports initiatives designed to facilitate the transition towards a climate-neutral and resilient society. The emphasis on coordination, open science, and addressing global challenges underscores the comprehensive approach taken by Horizon Europe in tackling climate-related issues.

This EU funding opportunity, HORIZON-CL5, titled "Better understanding and attribution of land and ocean carbon sources and sinks," is part of the Horizon Europe (HORIZON) program, specifically the CLIMATE (HORIZON-CL5-2027-01) call. It falls under the category of HORIZON Research and Innovation Actions (HORIZON-RIA) and utilizes the HORIZON Lump Sum Grant [HORIZON-AG-LS] model grant agreement. The deadline model is single-stage, with a planned opening date of 17 November 2026 and a deadline of 04 March 2027, 17:00:00 Brussels time.

The expected outcomes of this funding opportunity include:

Better understanding of oceanic carbon dioxide (CO2) sources and sinks, their drivers and dynamics under different climate scenarios, including their responses to human interventions.

Better understanding of land ecosystem CO2 sources and sinks, their drivers (both natural and anthropogenic) and their evolution under future climate and land-based mitigation scenarios.

Progress on reconciling estimates of anthropogenic CO2 emissions and removals from land originating from the climate science and national emissions reporting communities.

More consistent representation and quantification of lateral transfers of carbon.

The scope of this opportunity focuses on understanding the mechanisms and drivers of land (including inland waters) and ocean carbon sinks and sources, which is crucial for accurate climate models and scenarios and informing climate mitigation strategies. The funding aims to address significant gaps and uncertainties that remain in quantifying these complex processes and their components. It emphasizes the need to better understand the roles of anthropogenic and natural drivers of carbon fluxes, in particular the surface-to-air flux. This understanding is necessary for reconciling conceptual discrepancies among estimates and assessing the implications for future trends and mitigation potential, taking into account that mitigation actions need to be additional to natural processes and business-as-usual and that the remaining carbon budget depends, inter alia, on assumptions on sinks.

Proposals are expected to address only one of the three areas identified below, which should be clearly indicated, while ensuring coordination and cooperation across projects to address consistency in key factors, such as data, scenarios and models used or the representation of lateral transport of carbon (e.g., through river transport or harvest).

Area A:Oceanic CO2 sources and sinks

Projects are expected to improve the understanding and quantification of the various mechanisms involved, with a focus on the behaviour of the ocean sink under past (including palaeo records), present and future conditions and various climate change and emission scenarios. The projects should contribute to a better understanding of the biophysical potential for marine mitigation approaches (in particular carbon dioxide removal) and their implications over relevant timeframes, including feedbacks. The analysis should also include responses to ambitious mitigation (e.g., atmospheric stabilisation in line with policy objectives). Projects should build on the results of related earlier projects, in particular those under call HORIZON-CL6-2022-CLIMATE-01-02.

Area B:Land CO2 sources and sinks

Projects will aim to further our understanding of the key factors that have driven land carbon fluxes in the past and improving their quantification under present conditions and facilitating their projection under relevant climate and land use scenarios.

Area C:Reconciliation of different land use CO2 emission estimates

Through innovative approaches, the projects should enhance confidence in land-use CO2 flux estimates and enable more accurate assessments of national and collective climate progress, as well as alternative land-based climate policy options.

International cooperation is generally encouraged, in particular with low and lower/upper-middle-income countries.

The Joint Research Centre (JRC) may participate as member of the consortium selected for funding as a beneficiary with zero funding, or as an associated partner. Successful consortia will be asked to coordinate with projects that will be selected under ESA’s FutureEO programme to facilitate access to and uptake of satellite data products and related tools or methodologies.

This funding opportunity contributes to the destination of "Advancing science for a fair transition to a climate-neutral and resilient society (2026-27)". This destination aims to contribute to the “Advancing science for a transition to a climate-neutral and resilient society”.

The expected impacts of this destination include:

Supporting climate action (both mitigation and adaptation) in Europe and globally, through advancing climate science and the knowledge base underpinning actionable solutions, to accelerate the transition to a climate-neutral, climate-resilient and prosperous society.

Closing key knowledge gaps related to climate change, thereby contributing substantially to key European and international assessments such as IPCC, IPBES, EUCRA, and other initiatives such as the Coupled Model Intercomparison Project (CMIP) and the Coordinated Regional Climate Downscaling Experiment (CORDEX) under the World Climate Research Programme.

Strengthening the European Research Area on climate change by boosting scientific excellence and capacity in an inclusive manner across the participating countries.

Maximising synergies between mitigation and adaptation and with other policy priorities such as biodiversity and ecosystem preservation and restoration, disaster-preparedness, digitalisation, circular economy, prosperity and competitiveness, strategic autonomy, security and resilience, just transition, and the Sustainable Development Goals by exploring co-benefits, trade-offs and potential unintended consequences of climate strategies and policy interventions.

Important components of climate science research are also addressed in other Clusters -particularly Cluster 6 – which addresses the climate-ocean-cryosphere-polar nexus and the climate-energy-land-food-water-biodiversity nexus. Efforts to foster synergies and complementarities across these research activities are strongly encouraged.

General conditions for this opportunity include:

Admissibility Conditions:Proposal page limit and layout described in Annex A and Annex E of the Horizon Europe Work Programme General Annexes and Part B of the Application Form.

Eligible Countries described in Annex B of the Work Programme General Annexes.

Other Eligible Conditions:Projects using satellite-based earth observation, positioning, navigation and/or related timing data and services must use Copernicus and/or Galileo/EGNOS.

The Joint Research Centre (JRC) may participate as a member of the consortium.

Financial and operational capacity and exclusion are described in Annex C of the Work Programme General Annexes.

Evaluation and award criteria, scoring and thresholds are described in Annex D of the Work Programme General Annexes. To ensure a balanced portfolio covering different research areas (A, B and C), grants will be awarded to applications not only in order of ranking, but also to at least two highest ranked applications in each of areas A and B and at least one in Area C, provided that the corresponding applications attain all thresholds.

Submission and evaluation processes are described in Annex F of the Work Programme General Annexes and the Online Manual.

The indicative timeline for evaluation and grant agreement is described in Annex F of the Work Programme General Annexes.

Legal and financial set-up of the grants:Beneficiaries will be subject to additional obligations regarding open science practices, including open access to new modules, models, or tools. Eligible costs will take the form of a lump sum.

Specific conditions are described in the specific topic of the Work Programme.

Application and evaluation forms and model grant agreement (MGA):

Application form templates are available in the Submission System (Standard application form (HE RIA, IA)).

Evaluation form templates will be used with the necessary adaptations (Standard evaluation form (HE RIA, IA)).

Guidance is provided in the HE Programme Guide.

Model Grant Agreements (MGA) include HE MGA, HE Unit MGA, Lump Sum MGA, Operating Grants MGA, and Framework Partnership Agreement FPA.

Call-specific instructions include a detailed budget table (HE LS) and guidance on "Lump sums - what do I need to know?".

Additional documents include:

HE Main Work Programme 2026-2027 – 1. General Introduction

HE Main Work Programme 2026-2027 – 8. Climate, Energy and Mobility

HE Main Work Programme 2026-2027 – 15. General Annexes

HE Programme Guide

HE Framework Programme 2021/695

HE Specific Programme Decision 2021/764

EU Financial Regulation 2024/2509

Decision authorising the use of lump sum contributions under the Horizon Europe Programme

Rules for Legal Entity Validation, LEAR Appointment and Financial Capacity Assessment

EU Grants AGA — Annotated Model Grant Agreement

Funding & Tenders Portal Online Manual

Funding & Tenders Portal Terms and Conditions

Funding & Tenders Portal Privacy Statement

The budget overview for this topic in 2027 is as follows:

HORIZON-CL5-2027-01-D1-07 - HORIZON-RIA:€18,000,000, indicative number of grants: 3, contribution per grant around €6,000,000

HORIZON-CL5-2027-01-D1-08 - HORIZON-RIA:€14,000,000, indicative number of grants: 2, contribution per grant around €7,000,000

HORIZON-CL5-2027-01-D1-09 - HORIZON-RIA:€9,000,000, indicative number of grants: 3, contribution per grant around €3,000,000

HORIZON-CL5-2027-01-D1-10 - HORIZON-RIA:€18,000,000, indicative number of grants: 3, contribution per grant €5,000,000 to 6,000,000

HORIZON-CL5-2027-01-D1-11 - HORIZON-COFUND:€15,000,000, indicative number of grants: 1, contribution per grant around €15,000,000

HORIZON-CL5 - HORIZON-RIA:€25,000,000, indicative number of grants: 5, contribution per grant around €5,000,000

HORIZON-CL5-2027-01-D1-13 - HORIZON-RIA:€24,000,000, indicative number of grants: 6, contribution per grant around €4,000,000

There are 12 partner search announcements available for collaboration on this topic.

This Horizon Europe Research and Innovation Action aims to improve our understanding of carbon sources and sinks in both land and ocean ecosystems. The goal is to refine climate models, inform mitigation strategies, and reconcile differing estimates of carbon emissions. The funding is divided into three main areas: oceanic CO2 sources and sinks, land CO2 sources and sinks, and reconciliation of land use CO2 emission estimates. Projects must focus on only one of these areas but are encouraged to coordinate with other projects for consistency. International cooperation, especially with developing countries, is highly encouraged. The Joint Research Centre (JRC) may participate, and successful applicants will need to coordinate with projects from ESA’s FutureEO program. This initiative seeks to advance climate science, support effective climate action, and contribute to a climate-neutral and resilient society.

Eligible Applicant Types:The eligible applicant types are not explicitly stated, but based on the nature of Horizon Europe Research and Innovation Actions (RIA) and COFUND actions, eligible applicants typically include universities, research institutes, SMEs, large enterprises, and other organizations capable of conducting research and innovation activities. The encouragement of international cooperation suggests that entities from low and lower/upper-middle-income countries are also potentially eligible, although standard Horizon Europe funding rules apply.

Funding Type:The primary funding mechanism is a grant, specifically HORIZON Research and Innovation Actions (HORIZON-RIA) and HORIZON Programme Cofund Actions (HORIZON-COFUND). The eligible costs will take the form of a lump sum.

Consortium Requirement:The opportunity appears to require a consortium, as the text mentions "Successful consortia will be asked to coordinate" and "proposals should foresee sufficient means for effective coordination (i.e. cluster meetings, joint data management, potential joint actions)".

Beneficiary Scope (Geographic Eligibility):The geographic eligibility includes EU member states, associated countries, and potentially non-EU/non-associated countries, particularly low and lower/upper-middle-income countries, subject to Horizon Europe funding rules.

Target Sector:The program targets the climate, energy, and mobility sectors, specifically focusing on climate science, climate mitigation, climate adaptation, land ecosystems, and ocean ecosystems. It also involves Earth System Science and the use of satellite data.

Mentioned Countries:The opportunity mentions low and lower/upper-middle-income countries, but does not specify individual countries. It refers to EU member states and associated countries more broadly.

Project Stage:The expected maturity of the project is research and innovation actions, suggesting projects should be in the research, development, or validation stages.

Funding Amount:The funding amounts vary by topic, ranging from €9,000,000 to €25,000,000 per topic. The indicative grant amounts range from around €3,000,000 to around €15,000,000, with the number of grants per topic varying from 1 to 6.

Application Type:The application type is an open call, with a single-stage submission process.

Nature of Support:Beneficiaries will receive money in the form of a lump sum grant.

Application Stages:The application process involves a single stage.

Success Rates:The success rates are not explicitly mentioned, but the indicative number of grants per topic provides some insight into the potential success rate.

Co-funding Requirement:Co-funding is required for HORIZON-COFUND actions, but not necessarily for HORIZON-RIA actions.

Summary:This Horizon Europe call focuses on "Better understanding and attribution of land and ocean carbon sources and sinks." It aims to fund research and innovation actions that improve the understanding of carbon sources and sinks in oceanic and land ecosystems, reconcile different estimates of land-use CO2 emissions, and promote consistent quantification of lateral carbon transfers. The call is structured around three main areas: oceanic CO2 sources and sinks, land CO2 sources and sinks, and reconciliation of land use CO2 emission estimates. Proposals should address only one of these areas, while ensuring coordination and cooperation across projects. International cooperation, particularly with low and lower/upper-middle-income countries, is encouraged. The funding is provided as lump sum grants, and the application process involves a single stage. Successful projects are expected to contribute to a better understanding of climate change and support the development of effective mitigation and adaptation strategies. Consortia are expected to coordinate with other initiatives, such as ESA’s FutureEO programme, and make use of satellite data. The Joint Research Centre (JRC) may also be involved in selected projects.