Bracing for disaster: Over 60% of world’s rivers diverted or dammed

A significant new report on Saturday threw light on heightened extreme climate events across the world, including in India, attributing the disasters to enhanced human activity and broken connections in nature.

Nearly one-third of the Earth’s land surface has already been profoundly transformed by human activity, leaving ecosystems degraded and fragmented, according to the Global Land Outlook Thematic Report on Ecological Connectivity and Land Restoration. It was launched at the International Union for Conservation of Nature (IUCN) World Conservation Congress in Abu Dhabi.

Rivers are being cut by dams and urban growth is putting food, water, biodiversity and livelihoods at risk unless urgent action is taken, said the report.

Produced by the United Nations Convention to Combat Desertification (UNCCD) and the Convention on the Conservation of Migratory Species of Wild Animals (CMS), the study shows that Earth’s landscapes are interconnected like a living mosaic, held together by the movement of species and the natural flow of water, nutrients and energy. But today, these lifeline networks of rivers, forests and grasslands are increasingly under threat, disrupting and diminishing the functioning of natural systems.

The report reveals stark findings. More than 60 per cent of the world’s rivers have been diverted or dammed. It cites the striking example of Asia's Mekong, which was once the world’s most productive inland fishery and has now been fragmented by dams, disrupting fish migrations and threatening the food security of millions.

“Roads, railways and cities continue to carve up habitats, leaving only small, isolated patches of nature behind. Globally, the road network is projected to expand by 60 per cent by 2050, putting even more pressure on ecosystems," said the report, advocating the need to balance development with ecology.

It says the loss of connectivity harms both nature and people alike. “It weakens soil, shrinks harvests, worsens water shortage and leaves communities more exposed to droughts, floods and wildfires. Today, land degradation already affects up to 40 per cent of the planet, putting nearly half of humanity at risk. The way we grow food--combined with expanding infrastructure, pollution and climate change--is fragmenting landscapes and driving deforestation, biodiversity loss and breakdown in ecosystem functions," notes the report for policy makers to see.

Commenting on the findings, UNCCD Executive Secretary Yasmine Fouad said, “Life on our planet depends on healthy land and water systems--not only for nature, but for people. When these ties are broken, it is the most vulnerable who suffer first. This report shows that restoring ecosystems also means restoring the links between them. We must connect to restore and restore to connect.”

The report says healthy ecosystems are nature’s own infrastructure.

They keep water flowing, protect communities from extreme weather and secure food and drinking supplies. “When landscapes are restored at scale, they also lock away carbon, reduce disaster risks, protect biodiversity and create jobs," it states.

Speaking on the consequences of nature’s degradation, CMS Executive Secretary Amy Fraenkel said, “Conservation of the habitats that wild animals depend on is important for their survival, but it is not enough. Unless the ecological networks that wild animals rely on are restored and reconnected, migratory species of animals such as big cats, antelopes, freshwater fish and birds will continue to decline, with many species already critically endangered. These animals are integral parts of healthy, well-functioning ecosystems that nature and human communities rely on. Protecting these pathways is protecting our shared future.”

UNCCD Chief Scientist Barron Orr warned that delays in redressal could prove costly. “When soils are depleted and rivers polluted, recovery is slow and costly. Prevention and large-scale restoration are far more effective than waiting for collapse and then trying to repair it,” Barron said, urging countries to act.