Tibetan Plateau lakes to expand 50% by 2100 due to climate change: study

The lakes on the Tibetan Plateau, known as the "Roof of the World," are expected to transform in the coming decades. The findings, published in Nature Geoscience, warn that the surface area of these lakes could increase by 50 percent by the late 21st century, even under low emissions.

The Tibetan Plateau, 2.5 million square kilometers, hosts lakes crucial to the region's cycles. In recent decades, these lakes have been expanding due to changing climate, a trend expected to accelerate.

"Our results suggest that by 2100, even under a low-emissions scenario, the surface area of endorheic lakes on the Tibetan Plateau will increase by over 50% (~20,000 km2), and water levels will rise by around 10 meters relative to 2020," said Dr. Iestyn Woolway of Bangor University.

This expansion represents a fourfold increase in water storage compared to the 1970s to 2020, as noted in a paper on Nature.com.

Economic and environmental impacts

The projected lake could have severe economic and environmental impacts. The increased surface area could lead to loss of critical land for agriculture, human habitation, and road networks, potentially causing economic disruptions.

The researchers warned that without hazard mitigation measures, lake expansion is projected to submerge over 1,000 kilometers of roads, about 500 settlements, and around 10,000 square kilometers of ecological components like grasslands, wetlands, and croplands.

The study highlights a shift in the hydrological patterns of the Tibetan Plateau. Lake shrinkage gave way to expansion around 2021, primarily fueled by amplified lake water inputs from increased precipitation and glacier meltwater. This profound reshaping of the lake basins' hydrological connectivity is expected to have far-reaching consequences.

"Climate change is making the Tibetan Plateau greener and more habitable, attracting more people to higher altitudes due to better access to water," Dr. Woolway commented. "However, rising lake levels require urgent planning and policies to mitigate impacts on the region's ecology and population."

Landscape transformation and ecological impacts

Lakes merge and rivers change, leading to transformation, possibly leading to gas emissions and amplifying climate change.

Research indicates that the expansion of lakes will enhance lake–atmosphere interactions, potentially increasing greenhouse gas emissions and exacerbating global warming. In the future, rising lake water volumes will lower salinity, altering species abundance and nutrient composition in lake ecosystems. Additionally, the formation of new river channels from lake basin reorganization will impede the migration of plateau animals.

Moreover, an increase in freshwater and flow between lakes could disrupt existing ecological systems and affect wildlife. The study cites the example of the Zonang Lake in the Hoh Xil Nature Reserve, where a breach in 2011 blocked the migration route of the Tibetan Antelope.

The study underscores the urgent need for water hazard mitigation and management strategies across the Tibetan Plateau. Adequate adaptation measures must be implemented to protect against hydrological changes and their impact on infrastructure, human settlements, and ecosystems in the region.

"The expansion of lakes will increase lake-atmosphere exchange, which may lead to an increase in greenhouse gas concentrations in the atmosphere, further exacerbating global warming," warned Zhang Guoqing, a researcher at the Institute of Tibetan Plateau Research and a co-author of the study.

As the challenges posed by climate change continue to unfold, the Tibetan Plateau serves as a stark reminder of the far-reaching consequences that await if decisive action is not taken to mitigate and adapt to the ongoing environmental transformations.