Forests are a major source of emissions and also act as a carbon sink. Agriculture, forests and other land uses contributed 21% of global greenhouse gas (GHG) emissions between 2010-2019, with almost half due to deforestation. Globally, ecosystems absorb around one third of CO₂ per year. Restoring forests and improving land management practices could provide 20% to 30% of the emissions reductions needed to limit global warming to 1.5°C.

Governments increasingly recognise the importance of forests and are stepping up. Four years ago at COP26, 145 countries committed to halting and reversing deforestation by 2030. Yet, 2024 saw tropical deforestation reach its highest level in 20 years, and emissions from agriculture, forestry and other land uses continue to rise.

How can we turn these trends around?

This question is in the spotlight at COP30 in Belém, where the COP presidency has emphasised efforts to halt and reverse deforestation and forest degradation, and to conserve, protect and restore nature and ecosystems. Reflecting these priorities, the OECD is ramping up efforts to advance land-based climate action by developing new methodologies and data, guiding coherent policymaking, fostering finance, and driving local development, including through engagement with Indigenous peoples.

Measuring emissions from forests and agriculture is particularly challenging compared with other sectors. Agricultural emissions vary by crop and animal type, management practice, fertiliser and feed use, and soil and climatic conditions. Emissions and removals from forests also depend on soil and climate conditions, biomass growth and decay, as well as human interventions to clear, manage or create forests. Natural factors such as fires and diseases (which can be exacerbated by climate change) and the complexity of biological and chemical processes add to the challenge.

Better technologies are helping to overcome this. Remote sensing, satellite data and digital tools have made measurement easier, but integrating them into national monitoring and reporting processes requires new standards and methods. Recognising that better data drives more effective policy design, the OECD is looking into how satellite data can help track land use and carbon stock changes. New technologies can also be used to better track climate impacts such as wildfires, supporting adaptation efforts. OECD work also highlights the importance of tracking farm‑level emissions to inform product carbon footprints, shifting demand towards low-emission foods, and incentivising the uptake of better agricultural management practices. 

Forests are complex and diverse, and the effectiveness of forest policies depends on interactions between several contextual factors, e.g. biophysical characteristics, forest management histories, forest dwellers and Indigenous peoples, landowners, market forces, ecological phenomena and political systems at different levels. Ongoing work at the OECD – including an update of the Policy Inventory for Mitigation Actions in Agriculture, Forestry and Other Land Use Sectors (PIMA-AFOLU) database – is taking stock of and analysing various forest policy options and how they perform in different contexts.

Policy coherence also relies on breaking down policy siloes, leveraging synergies where possible, and recognising that where synergies are not possible, difficult choices will need to be made.

This year’s OECD Green Growth and Sustainable Development (GGSD) Forum on “Forests, agriculture & other land uses as a cornerstone of climate action”, held in July, gathered leading experts across government, business and civil society to examine the role of forests and agriculture in supporting climate action. Discussions highlighted three key areas for improved policy coherence:

Forests, and the carbon they store, are increasingly vulnerable to climate impacts. Extreme wildfires release large amounts of GHGs, and fires and drought both reduce carbon storage capacity. Fires in Portugal in 2017 turned the land use and forestry sector into a net carbon emitter, while California’s fires in 2020 released twice the emissions the state had managed to cut over the previous 15 years.

This highlights the risk of over-relying on forest carbon sinks to meet net-zero commitments. Some GHG emissions will linger in the atmosphere for centuries, but no institutional arrangement can guarantee that forest-based carbon sinks will remain as long. Forests are essential to net‑zero pathways – providing cost-effective mitigation options with significant co-benefits – but they cannot substitute for emissions reductions in other sectors. 

Agricultural expansion has caused around 90% of global deforestation and uses almost half of all habitable land. Under business-as-usual policies, estimates predict that agricultural production will increase by about 50% by 2050 to feed a growing world population. This cements the importance of land-use policies to avoid deforestation and drive progress on forest-based mitigation. Reforming environmentally harmful subsidies and reorienting them towards sustainable productivity growth, afforestation and restoration is critical.

Focusing on agricultural production alone, however, is not enough. Shifts in the food system are needed to reduce agriculture’s land requirements and halt deforestation. Demand-side policies could act to drive dietary shifts and supply chain initiatives to incentivise deforestation-free commodities. 

Forest-based climate policies often focus on their carbon emissions and sink functions, but forests are also vital biodiversity hotspots, drivers of economic opportunity and hold significant social and cultural value. By focusing too narrowly on carbon, forest policy may overlook important synergies between these benefits, prioritising quantity over quality. Biodiverse forests are often more resilient and better at storing carbon over the long term than monoculture stands dominated by a single species. Many forest benefits are local, so empowering local communities is key. Supported by strong and inclusive institutions, community-based forest management can unlock economic, social and environmental opportunities, including climate change mitigation.  

There is an urgent need to scale up finance for forests. International commitments to forest finance amounted to around USD 6 billion a year between 2021-2025. At the same time, countries spent USD 409 billion a year on agricultural support measures with particularly distorting effects on production and trade (2021-2023).

Carbon markets can help drive finance towards forests, but critical issues with calculating baselines, assessing additionality and ensuring integrity need to be ironed out. Jurisdictional approaches to forest crediting could help here, but come with their own challenges – as indicated in ongoing work under the OECD’s Carbon Market Platform.

Carbon markets alone are not sufficient, however. Finance is also needed to protect standing forests not (yet) under threat of deforestation. Effective protection requires long-term investments and managing significant uncertainty. This is difficult to square with the expectations of mainstream private investors – pointing to a potential role for governments in derisking and developing innovative financing instruments.

Finance should also account for the other benefits forests provide. Results-based payment schemes and other policy approaches can incorporate these other benefits, leveraging finance for biodiversity, and to support smaller-scale, seasonal or culturally rooted forest uses that do not align with carbon market incentives.

Local, forest-dependent communities and Indigenous peoples hold the key to forest protection and sustainable management. The best way to foster forest permanence is to allow communities to benefit from the ecosystem and economic benefits forests provide. OECD work on rural development aims to better understand the economic and community impacts of forests in rural regions, along with their diverse geographic functions, with particular emphasis on Indigenous communities. 

Leveraging the potential of forests as a cost-effective means to drive progress on climate action requires looking at the bigger picture. Yes, forests are important carbon sinks and deforestation is a significant source of emissions – but forests, and natural systems more generally, provide far more than just climate benefits. They are diverse and complex systems, and policy and management practices need to reflect these traits to be effective.

Discussions at the Green Growth and Sustainable Development Forum emphasised the various benefits provided by forests and the need for systems-wide approaches to drive change in the run-up to COP30. The OECD continues to work on forest-based climate action through its whole‑of-organisation initiative on Building Climate, Economic and Social Resilience.

Beyond COP30 in Belém, the nature-climate interface is expected to be high on the policy agenda. The 2025 OECD Green Growth and Sustainable Development Forum focused on the role of forests and agriculture in mitigating climate change. Watch the session replays and find OECD resources on the 2025 GGSD Forum website.

The OECD COP30 Virtual Pavilion went deeper into the topic of forests and climate mitigation. Join us at the following sessions or watch the replays:

Stocktaking and evaluating mitigation policies in agriculture, forestry and other land use sectors, 4 November 2025

Indigenous economies of the forest: Pathways for stewardship and shared value, 17 November 2025

Making agricultural trade more sustainable: What are countries doing?, 20 November 2025