Rijiju raises concerns over high aerosol levels accelerating glacial melting

Jammu, Dec 13: Aerosol levels have increased specifically over the Indo-Gangetic Plain (IGP) and the Himalayan foothills and have implications which may lead to increased temperatures, altered rainfall patterns and accelerated melting of glacier ice and snow.

Union Minister of Earth Sciences Kiren Rijiju stated this, in a written reply in the Lok Sabha on Wednesday, while referring to a study by the Indian Space Research Organization's (ISRO’s) Physical Research Laboratory.

Aerosols are solid or liquid particles or droplets suspended in air. They can be natural as well as artificial – the result of man-made activities, including the smoke from burning fossil fuels.

The findings are crucial for Jammu and Kashmir and Ladakh as well, given their geographic characteristics. Notably, the Hindu Kush-Himalaya-Tibetan Plateau region consists of the largest ice mass outside the Polar regions.

According to Rijiju, the study, using the ground-based observations of aerosol characteristics including radiative forcing data, reports that the “Aerosol Radiative Forcing Efficiency (ARFE) in the atmosphere is clearly high over the IGP and the Himalayan foothills (80–135 Wm-2 per unit Aerosol Optical Depth (AOD)), with values being greater at higher elevations.”

The aerosol-induced atmospheric warming and deposition of light-absorbing carbonaceous aerosols on snow and ice are reported to be the primary reasons for the current and future accelerated glacier and snow melt, the study has mentioned.

“It has been reported that the Black Carbon (BC) aerosol dominates (=75 %) the aerosol absorption over the Indo-Gangetic Plain including the Himalayas throughout the year and aerosols alone account for >50% of the total warming of lower atmosphere,” Rijiju noted, quoting the observations made in the ISRO study.

India represents a unique case for aerosol loading, properties and their effects. Varying aerosol sources get activated at different spatial and temporal scales. This changing nature of aerosols temporally and spatially when coupled with different land use nature across India, produces a very complex aerosol radiation-cloud-precipitation-climate interaction.

As per geologists and environmentalists, J&K is no exception to the worrisome trend.

Rijiju, in his reply, has mentioned that over the years, several institutes, universities and organizations in India have conducted active research under various government initiatives towards characterizing aerosol properties and their effects over the Indian region.

“Several Indian institutes, universities, organizations funded by the Government of India through Ministry of Earth Sciences (MoES), Department of Science & Technology (DST), Ministry of Environment Forest and Climate Change (MoEF & CC), Department of Space (DoS), Ministry of Mines (MoM) and Ministry of Jal Shakti (MoJS) monitor Himalayan glaciers for various scientific studies including glacier melting and have reported accelerated heterogeneous mass loss in Himalayan glaciers,” the Lower House was informed.

According to the minister, the “mean retreat rate of Hindu Kush Himalayan glaciers is 14.9 ± 15.1 meter/annum (m/a); which varies from 12.7 ± 13.2 m/a in Indus, 15.5 ± 14.4 m/a in Ganga and 20.2 ± 19.7 m/a in Brahmaputra river basins.”

“However, glaciers in the Karakoram region have shown comparatively minor length change (-1.37 ± 22.8 m/a), indicating the stable conditions,” it was stated.

Stating that the melting of glaciers is mostly a natural phenomenon, Rijiju said, “The recession or melting of glaciers is also caused by global warming and climate change. Therefore, the rate of melting of glaciers can’t be prevented or slowed down, unless all the factors responsible for global warming and climate change can be controlled.”

Just a day ago, Secretary Department of Disaster Management, Relief, Rehabilitation and Reconstruction (DMRRR) of the Union Territory of Ladakh had convened an important meeting of senior teams of National Disaster Management Agency (NDMA), Geological Survey of India, Central Ground Water Board, National Institute of Hydrology, Western Himalayan Regional Centre and Wadia Institute of Himalayan Geology, seeking attention towards an “unprecedented sudden surge in Hot Spring waters up to alarming heights in Chumathang area of Nyoma sub-division in Leh district.”

It was pointed out that the surge in water levels was up to 2-3 metres in about the last ten days of November this year which otherwise would remain normally up to average one foot level only, throughout the year.

The NDMA team is also exploring if some movement in tectonic plates is responsible for it, as this area already falls in a highly seismic zone category which can act as a prelude to future earthquakes occurrence here.