Why in News?

Scientists from Wadia Institute of Himalayan Geology (WIHG), Dehradun have found that glaciers in Sikkim are melting at a higher magnitude as compared to other Himalayan regions. Small-sized glaciers in Sikkim are retreating while larger glaciers are thinning due to climate change. 

About Glacier Melting

Today, Earth’s surface is made up of 71% water, 10% ice and 19% land. Most of the world’s ice is in the Arctic and Antarctic, but some of it is scattered around Earth in the form of mountain glaciers. The melting fresh water from glaciers alters the ocean, not only by directly contributing to the global sea level rise, but also because it pushes down the heavier salt water, thereby changing the Thermo Haline Circulation (THC), meaning currents in the ocean. This has an immediate effect on the near region, but ultimately the impacts can ripple far beyond the immediate area and climate.

Major Causes of Melting Ice Glaciers

  • Burning of fossil fuels: The burning of fossil fuels has resulted in the buildup of greenhouse gases in the environment thus influencing the warming trend because they trap heat in the atmosphere. The increase in temperatures is causing more and more glaciers to melt, consequently, this ends up exposing the earth underneath.
  • Oil and gas drilling: The oil and gas extraction process also emit methane, which is the main constituent in natural gas. The gas is more damaging to the environment than carbon dioxide, locking in heat more efficiently and escalating global warming, thus resulting in the glacier melting.
  • Deforestation: There is an increase in the release of carbon dioxide while less of it is being absorbed by trees because they are constantly reduced in number owing to deforestation. As a result, it hastens global warming and an increase in sea levels.
  • Ice breaking ships: During the months of summer, icebreaking ships head to the north into the Arctic Ocean, breaking through the ice at sea, the ships end up leaving trails of open waters. The Arctic sea ice is able to reflect most of the heat thus aiding in keeping the Arctic and the rest of the Northern Hemisphere cool.

Effects of Melting Ice Glaciers

  • Extreme flooding: There are areas that have ice glaciers on higher altitudes, and the melting is causing an abrupt rise in water input to other water bodies such as the rivers, lakes, and seas. The result is overflowing, which will be a major disaster as they will destroy everything on its way, and making thousands of creatures homeless.
  • Biodiversity loss: There are a lot of living organisms that rely mainly on glaciers for continued existence. With the increasing water temperatures and water levels, it will start affecting aquatic plants, the fish species will reduce and so will be the survival of the birds and animals that are dependent and adapted to the glacier habitats.
  • Scarcity of fresh water: Only 2% of the water available is fresh water that people can consume. Over 70% consists of glaciers and snow. With the increase in population and reducing the mass of glaciers, there will be a serious scarcity of fresh water in the coming years.
  • Coral Reefs will disappear: Coral reefs need sunlight for the process of photosynthesis, enabling their survival. When water levels increase due to glacier melting, sufficient sunlight will not be able to reach the corals.
  • Recontamination of the environment: A lot of chemical pollutants and pesticides became airborne and finally got deposited in the cold places that contain glaciers, and the harmful chemicals stay trapped in the layers. The rapid melting of glaciers may discharge the chemicals back into the surroundings and water bodies.

Effect on Sikkim Himalayas

Compared to other Himalayan regions, the magnitude of dimensional changes and debris growth are higher in the Sikkim.  A major shift in glacier behavior has occurred around 2000. Contrary to the western and central Himalaya, where glaciers are reported to have slowed down in recent decades, the Sikkim glaciers have shown negligible deceleration after 2000. Summer temperature rise has been prime driver of glacier changes.

Way Forward

Accurate knowledge of magnitude as well as the direction of glacier changes, as highlighted in the present study, can lead to awareness among common people regarding water supplies and possible glacier hazards, particularly to those communities that are living in close proximity. The study can provide ample baseline data on glacier changes and systematically explore the causal relationship between glacier parameters and various influencing factors. A clear understanding of glacier state will help orienting future studies as well as taking necessary measures.