Deforestation - Definition and Facts

Deforestation is the conversion of forest to other land use independently of whether human-induced or not (FAO, 2023). 

Primary reference(s)

​​​FAO, 2023. Terms and Definitions. FRA 2025. Food and Agriculture Organization of the United Nations (FAO). Forest Resources Assessment Working Paper No. 194. Accessed 21 November 2024.

Annotations

Additional scientific description

The Food and Agriculture Organization of the United Nations (FAO) has monitored the world's forests at 5- to 10-year intervals since 1946. The recent Global Forest Resources Assessments have been produced every five years in an attempt to provide a consistent approach to describing the world's forests and how they are changing (FAO, 2020).

Deforestation includes the permanent reduction of the tree canopy cover below the minimum 10% threshold. It also includes areas of forest converted to agriculture, pasture, water reservoirs, mining, other infrastructure and urban areas. The term specifically excludes areas where the trees have been removed as a result of harvesting or logging, and where the forest is expected to regenerate naturally or with the aid of silvicultural measures. The term also includes areas where, for example, the impact of disturbance, over-utilisation or changing environmental conditions affects the forest to an extent that it cannot sustain a canopy cover above the 10% threshold (FAO, 2023).

Deforestation and forest degradation continue to take place at alarming rates and contribute significantly to the ongoing loss of biodiversity (FAO and UNEP, 2020). Since 1990, it is estimated that 420 million hectares of forest have been lost through conversion to other land uses, although the rate of deforestation has decreased over the past three decades (FAO, 2020a).

Between 2015 and 2020, the rate of deforestation was estimated at 10 million hectares per year, down from 16 million hectares per year in the 1990s. The area of primary forest worldwide has decreased by over 80 million hectares since 1990 (FAO, 2020).

Agricultural expansion continues to be the main driver of deforestation and forest degradation and the associated loss of forest biodiversity. Large-scale commercial agriculture (primarily cattle ranching and cultivation of soya bean and oil palm) accounted for 40% of tropical deforestation between 2000 and 2010, and local subsistence agriculture for another 33% (FAO & UNEP, 2020).

Metrics and numeric limits

Deforestation area expressed in thousand hectares per year for the following periods: 1990-2000, 2000-2010, 2010-2015 and 2015-2020 (FAO, 2020).

The data for the Global Forest Resources Assessment are collected using an online tool that also serves as a data dissemination platform. All data countries and territories reported to Global Forest Resources Assessment 2020 are available here (FAO, no date).

Key relevant UN convention / multilateral treaty

Convention on Biological Diversity (CBD): Established in 1992 and entered into force on 29 December 1993, the convention has three main objectives: the conservation of biological diversity; the sustainable use of the components of biological diversity; and the fair and equitable sharing of the benefits arising out of the utilisation of genetic resources (CBD, 1992).

United Nations Framework Convention on Climate Change (UNFCCC): Negotiated from February 1991 to May 1992, the Convention entered into force on 21 March 1994. It seeks to reduce atmospheric concentrations of greenhouse gases, with the aim of preventing dangerous anthropogenic interference with the Earth’s climate system. At the Conference of the Parties (COP21) in Paris, on 12 December 2015, Parties to the UNFCCC reached a landmark agreement to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low-carbon future (UNFCCC, 2015).

United Nations Convention to Combat Desertification (UNCCD): Established in 1994, this Convention is the sole legally binding international agreement linking environment and development to sustainable land management. The Convention addresses specifically the arid, semi-arid and dry sub-humid areas, known as the drylands, where some of the most vulnerable ecosystems and peoples can be found (UNCCD, 2017).

The United Nations Strategic Plan for Forests 2017–2030: Launched in 2017, this strategy provides a global framework for action for sustainable forest management, and to end deforestation and forest degradation. It encompasses a set of six Global Forest Goals and 26 associated targets to be voluntarily achieved by 2030. Among others, it includes a target to increase forest area by 3% worldwide by 2030, which translates into an increase of 120 million hectares (United Nations, 2017).

Drivers

Agricultural expansion is the main driver of deforestation and forest fragmentation and the associated loss of forest biodiversity.

Impacts

In the tropical domain, the net annual loss of forest area from 2000 to 2010 was about 7 million hectares, and the net annual increase in agricultural land area was more than 6 million hectares. There were significant regional variations: Central and South America, sub-Saharan Africa, and South and Southeast Asia all had net losses of forest and net gains in agricultural land (FAO & UNEP, 2020). Small-scale farming was the main global driver of the majority of the converted forest to cropland and grassland during the 2000–2018 period, which amounted to 68% of all agriculture-driven deforestation—40% for cropland and 28% for livestock grazing (Branthomme et al., 2023).

Multi-hazard context

The figure below summarises common interactions between deforestation and other hazards. This information should be used with caution and not be solely relied upon in disaster risk management, particularly as some interactions may not have been included. Note that hazardous events occurring together or locally in space or time may not necessarily cause, amplify or be otherwise related to each other. Specific examples of multi-hazard context can be found in the ‘Hazard drivers’ and ‘Impacts’ sections above.

Multi-hazard diagram

Monitoring

The section and the table below offer an overview of monitoring for deforestation. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.

References

Branthomme, A., Merle, C., Kindgard, A., Lourenço, A., Ng, W-T., D’Annunzio, R. Shapiro, A. 2023. How much do large-scale and small-scale farming contribute to global deforestation? Results from a remote sensing pilot approach. Rome, FAO. DOI: 10.4060/cc5723en. Accessed 21 November 2024.

CBD, 1992. Convention on Biological Diversity. Accessed 21 November 2024.

FAO, no date. Global Forest Resources Assessment. Accessed 21 November 2024.

FAO, 2020. Global Forest Resources Assessment 2020. Main report. DOI: 10.4060/ca9825en. Accessed 21 November 2024.

FAO, 2023. Global Forest Resources Assessment 2025. Terms and Definitions FRA 2025. Food and Agriculture Organization of the United Nations (FAO). Forest Resources Assessment Working Paper No. 194. Accessed 21 November 2024.

FAO and UNEP, 2020. The State of the World’s Forests 2020. Forests, biodiversity and people. Food and Agriculture Organization of the United Nations (FAO) and United Nations Environment Programme (UNEP). DOI: 10.4060/ca8642en. Accessed 21 November 2024.

UNCCD, 2017. United Nations Convention to Combat Desertification in those countries experiencing serious drought and/or desertification, particularly in Africa. Accessed 21 November 2024.

UNFCCC, 2015. Paris Agreement. United Nations Framework Convention on Climate Change (UNFCCC). Accessed 21 November 2024.

United Nations. 2017. ECOSOC Resolution 2017/4: United Nations Plan for Forests 2017-2030 and quadrennial programme of work of the United Nations Forum on Forests for the period 2017-2020 E/RES/2017/4. Accessed 21 November 2024.

Cite this

United Nations Office for Disaster Risk Reduction (UNDRR), & International Science Council (ISC). (2025). UNDRR–ISC Hazard Information Profiles – 2025 Update: EN0201 Deforestation United Nations Office for Disaster Risk Reduction; International Science Council. https://www.undrr.org/terms/hips/EN0201  [Copy citation]

This part of the article was originally published by the United Nations Office for Disaster Risk Reduction (UNDRR), which can be accessed through this link: https://www.undrr.org/understanding-disaster-risk/terminology/hips/en0201