Freshwater ecosystems are being rapidly lost, driven by land-use change
Across the world’s blue water and green water freshwater ecosystems, human-driven degradation and conversion is resulting in enormous loss of freshwater ecosystems: an estimated 30% have disappeared since 1970. Land-use change has been the leading driver contributing to these losses. For instance, between 2000 and 2020, the primary drivers of mangrove loss were shrimp, palm oil and rice cultivation, making up 43% of total destruction.
Similarly, conversion to industrial plantations, logging and associated agricultural practices are leading contributors to tropical peatland degradation; agriculture and urbanization also drive the majority of degradation in river and lake ecosystems. And deforestation caused by increasing agriculture, industry and urban development is directly driving a reduction in green water flows and downwind precipitation.
Ecosystem loss is bringing devastating consequences for climate and biodiversity
These conversion and degradation patterns are resulting in the disruption or loss of the critical ecosystem services that the world’s freshwater ecosystems provide. These services include water filtration; flood protection; drought buffering; nutrient cycling; provision of food and energy; cultural, spiritual and recreational benefits; and carbon storage and local climate regulation. Together, they provide an estimated $39 trillion in value each year — just one measure underscoring their central role in supporting both planetary health and human well-being.
The degradation and loss of freshwater ecosystem services is especially concerning from a climate mitigation perspective. An estimated 20-25% of the world’s soil carbon is stored in wetlands, and some freshwater ecosystems — specifically mangrove forests, peatlands and salt marshes — are among the most carbon-dense globally. Mangroves and peatlands hold at least three times as much carbon per hectare as boreal, temperate and tropical forests, and protecting and restoring these coastal wetlands also considerably enhances carbon storage in ocean sediments.
Converting and degrading freshwater ecosystems, in contrast, releases carbon stored over centuries to millennia back into the atmosphere as well as inhibits these ecosystems’ capacity to take up and store additional carbon dioxide. Disturbance of green water flows that infiltrate soil and are used by plants can also reduce regional cooling effects, as this vegetation helps naturally cool surrounding areas by releasing water vapor back to the atmosphere.
Additionally, approximately 85% of globally assessed freshwater species diversity has been lost since 1970 — twice the rate of terrestrial and marine biodiversity decline — and nearly one-quarter of remaining freshwater species assessed are now threatened with extinction. Conversion of freshwater ecosystems is the primary threat, not only reducing habitat extent but also fragmenting and degrading remaining freshwater habitats. As the total abundance and richness of freshwater species shrinks, recovery becomes increasingly difficult, if not impossible, as species face a debilitating recovery debt.
Protecting freshwater ecosystems is critical, but efforts to date have stalled
Addressing the world’s climate and biodiversity crises while safeguarding and enhancing access to water for essential services will largely depend on halting the degradation and conversion of freshwater ecosystems. However, collective progress to effectively protect freshwater ecosystems remains inadequate; all indicators that have sufficient data to assess progress are heading in the wrong direction.
Urgent, coordinated global action is needed to reverse these trends. Strong evidence suggests that certain conservation tools, such as protected areas and other effective area-based conservation measures, payments for ecosystem services, moratoria on ecosystem conversion, and strengthened collective land ownership and land rights for Indigenous Peoples, Afro-descendant Peoples and local communities can effectively reduce rates of ecosystem conversion.
Creating and strengthening policies that facilitate and incentivize these efforts should also be a top priority. These policies must also be coupled with efforts to improve governance, as limited institutional capacity and insufficient resources often hinder the effectiveness of conservation efforts around the globe. At the same time, transformations across agriculture, industry and cities will be paramount to ensure that as demand for food, energy and water rises, these systems use freshwater resources as efficiently and sustainably as possible and do not contribute to further degradation of freshwater ecosystems.
Join us on August 13 for a high-level discussion on the state of the global freshwater system and the urgent actions needed to accelerate change.
