Forum for Science, Industry and Business

Himalayan glaciers retreating at accelerated rate in some regions but not others

The report examines how changes to glaciers in the Hindu Kush-Himalayan region, which covers eight countries across Asia, could affect the area's river systems, water supplies, and the South Asian population. The mountains in the region form the headwaters of several major river systems -- including the Ganges, Mekong, Yangtze, and Yellow rivers -- which serve as sources of drinking water and irrigation supplies for roughly 1.5 billion people.

The entire Himalayan climate is changing, but how climate change will impact specific places remains unclear, said the committee that wrote the report. The eastern Himalayas and Tibetan Plateau are warming, and the trend is more pronounced at higher elevations. Models suggest that desert dust and black carbon, a component of soot, could contribute to the rapid atmospheric warming, accelerated snowpack melting, and glacier retreat.

While glacier melt contributes water to the region's rivers and streams, retreating glaciers over the next several decades are unlikely to cause significant change in water availability at lower elevations, which depend primarily on monsoon precipitation and snowmelt, the committee said. Variations in water supplies in those areas are more likely to come from extensive extraction of groundwater resources, population growth, and shifts in water-use patterns. However, if the current rate of retreat continues, high elevation areas could have altered seasonal and temporal water flow in some river basins. The effects of glacier retreat would become evident during the dry season, particularly in the west where glacial melt is more important to the river systems. Nevertheless, shifts in the location, intensity, and variability of both rain and snow will likely have a greater impact on regional water supplies than glacier retreat will.

Melting of glacial ice could play an important role in maintaining water security during times of drought or similar climate extremes, the committee noted. During the 2003 European drought, glacial melt contributions to the Danube River in August were about three times greater than the 100-year average. Water stored as glacial ice could serve as the Himalayan region's hydrologic "insurance," adding to streams and rivers when it is most needed. Although retreating glaciers would provide more meltwater in the short term, the loss of glacier "insurance" could become problematic over the long term.

Water resources management and provision of clean water and sanitation are already a challenge in the region, and the changes in climate and water availability warrant small-scale adaptations with effective, flexible management that can adjust to the conditions, the committee concluded. Current efforts that focus on natural hazard and disaster reduction in the region could offer useful lessons when considering and addressing the potential for impacts resulting from glacial retreat and changes in snowmelt processes in the region.

Many basins in the region are "water-stressed" due to both social changes and environmental factors, and this stress is projected to intensify with large forecasted population growth, the committee concluded. Climate change could exacerbate this stress in the future.

Although the history of international river disputes suggests that cooperation is a more likely outcome than violent conflict in this region, social conditions could change. Therefore, modifications in water supplies could play an increasing role in political tensions, especially if existing water management institutions do not evolve to take better account of the region's social, economic, and ecological complexities, the committee said.

The National Research Council, the operating arm of the National Academy of Sciences and National Academy of Engineering, is an independent, nonprofit institution that provides science and technology advice under a congressional charter granted to the NAS in 1863. A committee roster follows.

Contacts:

Jennifer Walsh, Media Relations Officer

NATIONAL RESEARCH COUNCIL

Division on Earth and Life Studies

Board on Atmospheric Sciences and Climate and Water Science and Technology Board

Division of Behavioral and Social Sciences and Education Committee on Population

Committee on Himalayan Glaciers, Climate Change, and Implications for Downstream Populations

Jennifer Walsh | EurekAlert!
Further information:
http://www.nas.edu

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...