A fifth of world's wetlands may vanish by 2050, scientists warn

Mail & Guardian

5 days ago

The destruction of wetlands affects water availability, biodiversity, climate stability and the wellbeing of all life, including people's livelihoods. Photo: File
This is according to a
This puts up to $39 trillion in ecosystem benefits at risk, more than any other ecosystem.
The report found that since 1970, at least 400 million hectares of wetlands have been lost — that is 22% of the global total. And nearly a quarter of those that have survived are in a degraded state, a figure that is increasing.
Degradation is now as pressing a concern as outright loss, the report said, warning that these losses significantly affect water availability, biodiversity, climate stability and human well-being.
The report was launched before the 15th Meeting of the Conference of the Contracting Parties (COP15) to the Convention on Wetlands in Victoria Falls, Zimbabwe, which starts on Wednesday.
Despite covering just 6% of the Earth's surface, wetlands provide ecosystem services that include clean water, food production, flood protection and carbon storage that total more than 7.5% of global GDP. They also support a disproportionately high share of livelihoods across sectors such as agriculture, aquaculture and tourism.
Yet every year, 0.52% of wetlands are lost, undermining efforts to tackle climate change and biodiversity loss. The report noted that these losses are unevenly distributed, with the highest rates occurring in low-income regions where wetlands are more ecologically critical and closely linked to local livelihoods, food systems and water supplies.
National reports submitted under the Convention on Wetlands and global citizen science data confirm that the ecological condition of wetlands is deteriorating in most regions, particularly in Africa, Latin America and the Caribbean. But their situation is increasingly worsening in Europe and North America.
The wetland types that have experienced the most significant historical declines include inland marshes, peatlands and lakes. Despite their immense value, wetlands continue to be lost or degraded at an alarming rate, 'threatening our collective future', wrote Musonda Mumba, secretary-general of the convention, in the report's foreword.
'The data presented in this outlook are sobering,' she said. 'Wetland degradation is widespread across all regions. Millions of hectares have been lost. Many freshwater species remain at risk.'
The societal costs — from reduced access to clean water and increased vulnerability to disasters to rising emissions — are escalating.
'The economic value of the wetlands lost in the last 50 years exceeds $5.1 trillion, yet this figure does not fully reflect their intrinsic worth or cultural significance. While restoration is essential, prevention is more cost-effective. Once degraded, wetlands are expensive and difficult to restore,' Mumba noted.
Cumulative pressures, including land-use change, pollution, agricultural expansion, hydrological disruption, invasive species and the effect of climate change — such as rising sea levels and drought — are driving these declines.
'These drivers are frequently interlinked, leading to nonlinear and difficult-to-reverse degradation processes,' the report said.
National reports to COP15 showed that 74% of countries are undertaking wetland restoration to some extent, 66% have national targets in place, and more than 70% have identified priority sites. 'However, progress is uneven, and only a limited number of countries are implementing restoration at sufficient scale,' the report said.
It detailed how vulnerable and disadvantaged groups in society receive fewer of the benefits of wetlands than those with greater assets (such as property rights, financial capital and social status), but are also more dependent upon the goods and services provided by natural wetlands.
'Similarly, when wetlands are converted to other land uses, notably intensive agriculture or built infrastructure, ownership of the benefits tends to be held privately and by those with greater assets, while the cost of losing the wetland ecosystem services tends to fall on the disadvantaged …
'Additionally, disadvantaged groups tend to be more reliant upon regulating services provided by wetlands, such as flood protection and clean water, because they tend to live in more vulnerable areas and have less access to alternative (engineered) options.'
Peatlands store more carbon than any other terrestrial ecosystem yet many are degraded and now emit greenhouse gases rather than storing them. Coastal wetlands, such as mangroves, seagrasses and salt marshes, sequester carbon rapidly, and buffer coastlines from rising sea levels and storms.
Inland wetlands, such as rivers, lakes and marshes, regulate water flows to help prevent flooding and sustain water supplies during droughts. The report said that without urgent investment in these systems, climate goals will remain out of reach.
Four pathways are outlined to reversing wetland loss and 'unlocking nature-positive investment'.
These include integrating wetland value in decision-making; recognising wetlands as key to the global water cycle — for their role in storing, filtering, and regulating water; embedding wetlands in innovative financing mechanisms — including carbon markets, resilience bonds and blended finance; and mobilising public and private resources for wetland restoration.
The report features a wide selection of case studies that demonstrate progress is possible — and prevention is cheaper than restoration, which can cost anywhere from
$1 000 to $70 000 a hectare depending on the ecosystem.
In Zambia's Kafue Flats, an
A national case study from South Africa highlights the new automated wetland condition assessment methodology developed through the
The innovative approach involves 'GIS automation and stakeholder validation to provide a scalable, cost-effective way of tracking wetland ecosystem conditions across the country', the report noted.
Coenraad Krijger, the chief executive of Wetlands International, said in a statement that the report is a sobering read, but 'it does showcase pathways to a brighter future — if we all work together'.