Why Tropical Forest Loss Persists: A Framework for Transformative Conservation Action

While covering only 14% of Earth's land area (Dinerstein et al. 2017), tropical forests are vital for biodiversity conservation, climate regulation, and ecosystem services. They harbor at least 50% of Earth's biodiversity (Lewis et al. 2015) and store 54% of the planet's forest carbon stock (Pan et al. 2024). Their average ecosystem service value per unit area, encompassing provisioning, regulating, habitat, and cultural services, is 75% higher than that of temperate forests (de Groot et al. 2012). These figures alone underscore the global significance of tropical forests and reinforce why their conservation should remain part of the central priorities for sustainability. Concerns about tropical forest depletion are not new. As early as the 1940s, scientists and conservationists warned of rising pressures on tropical forests and emphasized that they must be protected and conserved for future generations (Corner 1946). In the early 1970s, researchers documented the rapid degradation of these ecosystems, attributing forest loss primarily to human activities such as agricultural expansion (Gómez-Pompa et al. 1972). They regarded tropical forests as a nonrenewable resource, noting that their destruction was occurring faster than natural regeneration processes, leading to the irreversible loss of ecological functions. Yet, despite decades of awareness, global tropical forest loss persists. In 1960, tropical forests covered an estimated 2001 million hectares, but by 2019, this had declined to 1814 million hectares, representing a net loss of 187 million hectares, equivalent to 2.5 times the size of the entire Borneo Island (Figure 1a). Satellite-based monitoring further indicates that although annual tropical forest loss declined during 2016–2021, it went up again in 2022–2024, and the average annual rate remains above the pre-2015 level (Figure 1b). The year 2015 marks the adoption of both the Sustainable Development Goals (SDGs) and the Paris Agreement. Consistent with observations from the 1970s (Gómez-Pompa et al. 1972), recent assessments show that most tropical forest loss occurs in landscapes dominated by agricultural production systems (Pendrill et al. 2022). The central question, therefore, is this: if tropical forests are indeed vital, why has their loss, recognized for more than half a century, remained unresolved? This paper argues that global tropical forest loss has become a deeply embedded systemic issue. Effectively addressing it requires first clarifying and understanding the system in which it is rooted. To help unravel the system of global tropical forest loss, a general framework is proposed. This framework categorizes the drivers of tropical forest loss into natural and anthropogenic (Figure 1c). Natural drivers include wildfires, pests and diseases, volcanic eruptions, landslides, and other forms of natural disturbance. Anthropogenic drivers encompass activities such as deforestation (or the conversion of forests to other land uses such as for agriculture), timber harvesting, and mining, ranging from household-level to large-scale operations. Given their predominant role in shaping current trends, this framework places emphasis on anthropogenic drivers. A key contribution of this framework is its explicit focus on the “environment” that enables tropical forest loss (Figure 1c). It identifies national policies and governance as the primary enablers, particularly land use-related policies that designate land, including forests, for specific purposes. Deforestation, logging, and mining depend on such policies regardless of the scale of operation. For example, forests cannot be converted to pasture or to soya, oil palm, or rubber plantations without policy authorization. Similarly, logging and mining operations require government-issued licenses. National policies are shaped by a range of internal and external factors (Figure 1c). Internal factors include a country's economic, social, and environmental needs, goals, and priorities, whereas external factors encompass global demand for forest-related products and international trade policies. These factors interact dynamically. For example, national goals and priorities may shift in response to global market trends, while trade policies reflect a country's strategic interests. At the same time, national policies influence and reshape both internal and external factors, reinforcing a complex and interconnected system. The needs, goals, and priorities of a country are also dynamically shaped by feedback from the outcomes of various activities, which in turn influence national and trade policies (Figure 1c). For example, land use policies may be revised or new trade policies negotiated in response to emerging needs. Simultaneously, the “environment” evolves in response to the broader social-ecological consequences of tropical forest loss, including greenhouse gas emissions, biodiversity decline, and increased disaster risk and vulnerability, key themes in international initiatives such as the SDGs (https://sdgs.un.org), the Paris Agreement (https://unfccc.int/), the Glasgow Leaders' Declaration on Forests and Land Use (https://forestdeclaration.org), the Kunming-Montreal Global Biodiversity Framework (https://www.cbd.int/gbf), and the recently launched Tropical Forests Forever Facility (https://cop30.br). As global efforts evolve, they interact with national priorities and further shape the “environment.” Addressing global tropical forest loss therefore requires transforming the “environment” that enables, facilitates, and sustains it into one that at least moves toward a disabling state, thereby tackling its systemic nature. This is a complex and formidable challenge. At the heart of this challenge lies the “elephant in the room”: national policies and governance, a politically sensitive issue. Each nation has sovereignty and the right to manage its resources according to its needs, goals, and priorities. Developing tropical countries, in particular, face the dual challenge of advancing socioeconomic development while conserving their forests that are rich in biodiversity and provide essential ecosystem services. A previous study, aligned with the forest transition theory, found that more developed, higher-income countries exhibited more favorable forest change trends, suggesting that less developed, lower-income nations would need to, unless they receive essential assistance in a timely manner, first strive to attain economic progress and stability to enhance their capacity to curb forest losses (Estoque et al. 2022). This reality illustrates the difficulty of reconciling global conservation goals with national development imperatives. Despite these challenges, strengthening national policy frameworks remains crucial. Country-level initiatives should promote sustainable agriculture while reducing incentives for large-scale deforestation. Developed nations also play a critical role and should reconsider their reliance on tropical forest-related products (Estoque et al. 2022). For example, rather than depending heavily on imported tropical timber, they could utilize their own forests, particularly in temperate regions where forest cover has increased over the past decades. Needless to say, in terms of biodiversity conservation, habitat loss in the tropics cannot be offset on a like-for-like basis by habitat gains in temperate regions. As part of strengthening national policies and governance, the implementation of international agreements must also be enhanced. A recent assessment revealed significant gaps in forest protection, management, and restoration within Nationally Determined Contributions under the Paris Agreement, indicating insufficient national action to meet global conservation goals (https://www.unep.org/resources/report/raising-ambition-accelerating-action-towards-enhanced-nationally-determined). Tropical forest loss also continues even within protected areas, further undermining biodiversity conservation goals. Consequently, governance mechanisms must be strengthened to ensure that commitments are effectively fulfilled and translated into action. To clarify and better understand the system of global tropical forest loss (Figure 1c), advancing interdisciplinary research is essential, as tropical forest loss is simultaneously an ecological, economic, and political issue. A key research priority is to clarify the factors that create and sustain the “environment” enabling persistent tropical forest loss. Understanding how international trade agreements influence national forest-related policies and whether they deter or encourage tropical forest loss requires deeper analysis. Remote sensing must continue to play a vital role in monitoring forest change and helping to elucidate its drivers. Research should also distinguish the extent to which forest loss is driven by anthropogenic versus natural causes and examine governance failures, including legal and illegal forest loss, as well as the relationship between corruption and policy enforcement. Further research should also assess the contributions of tropical forest loss at different scales, from households and smallholders to large enterprises, and evaluate how foreign direct investment in agriculture, mining, and infrastructure shapes national land use- and forest-related policies. Strengthening indigenous land rights and tenure systems offers another promising avenue, as these can help reshape the “environment” toward more sustainable land management. Finally, research should examine how social movements, civil society, and public awareness campaigns influence forest-related policies and shift political incentives toward conservation. In summary, transforming the “environment” that enables persistent tropical forest loss into one that at least approaches a disabling state requires a systemic, multi-level approach. Key actions include strengthening national policies and governance, aligning development priorities with conservation objectives, enhancing implementation of international agreements, and empowering local communities and indigenous peoples. Central to all these actions is interdisciplinary research that clarifies systemic drivers, informs evidence-based policies, and ensures effective, transformative conservation outcomes. By addressing these research gaps and transforming the “environment,” we can move toward a more comprehensive understanding of the systemic forces that sustain tropical forest loss. Only through such systemic insights can transformative conservation actions emerge to protect one of the planet's most vital and irreplaceable ecosystems. This work was supported by the Japan Society for the Promotion of Science (JSPS) through its Grants-in-Aid for Scientific Research (KAKENHI) Program: Grant-in-Aid for Scientific Research (C), Number 22K01038 (Principal Investigator: Ronald C. Estoque) and (B) (Number 24K01817, Principal Investigator: Shoji Hashimoto). The views expressed in this paper are those of the author and do not necessarily reflect the positions of his institution or the funder. The author declares no conflicts of interest. The data used in Figure 1a,b are from publicly available sources and are provided in the figure caption.