Himalayas play a vital role in modulating the global weather and climate, especially the Asian Monsoon. The large rivers viz. Indus, Ganges, Brahmputra, Irravady, Salween, Mekong, Yangtze and Yellow originate from the Himalayas and provide much of the freshwater to 1.4 billion people in Asia. Their river plains provide food to almost 40% of the world’s population, said Prof. Nayak, Director, National Institute of Advanced Studies (NIAS), Bengaluru on the forum of Society for Promotion of Science & Technology in India (SPSTI) and Chandigarh Chapter of National Academy of Sciences, India (NASI) on Tuesday, March 09, 2021.
The Webinar was organized with support from Haryana State Council for Science, Innovation and Technology with a motive to aware the people about the profound impact of Himalayas on social, economic, cultural and demography of India, Bhutan, Tibet, China, Nepal and Pakistan. Prof. Nayak delivered the talk online on ‘Cooperation to Preserve the Himalayan Ecological System’ which was coordinated by Prof. Arun K. Grover, former Vice Chancellor of Panjab University. Prof. R. Baskar, of the Department of Environmental Studies, GJU Hisar introduced the speaker Dr. Shailesh Nayak.
Dr. Nayak stated that apart from playing an important role in the ecosystem, Himalaya has a vital role in moderating the global weather and climate especially the monsoon in Asia. There are many rivers which originate from Himalaya and are major sources for freshwater and provide food to 40% of the world’s population. The Himalayas are the largest snow and ice concentration outside the Arctic and Antarctica and the high albedo of snow and ice has a cooling effect on mountains but have a warming effect over Persian Gulf and Arabian Peninsula. It has trapped reserves of carbon, prone to natural hazards, earthquakes, wetlands and has unique biodiversity. The Himalaya large cover has profound impact on social, economic, cultural and demography of not only India, Bhutan, Tibet China, Nepal and Pakistan but it also impacts Myanmar, Afghanistan, Bangladesh, Laos, Thailand and Vietnam.
He briefly discussed the evolution of Himalaya which goes back to nearly 133 million years ago with the fragmentation process of Gondwanaland. Talking about the issues relating with Himalaya, he said when Himalaya rose the rivers started eroding it and the sediments got deposited in Arabian sea and Bay of Bengal. To understand the evolution of Himalaya and origin of monsoon, a project was taken with the support from US, and very deep drilling was carried out in the Arabian Sea in 2015, and an analysis of cores provided evidence that SAM intensification took place around 3.2 to 2.8 million years ago. Another important aspect that he focused was the rivers that took large amounts of water to Bay of Bengal are reducing its salinity and leading to strong monsoon current arising from Bay of Bengal. Also, large amounts of sediments that come from Himalaya to Bay of Bengal can prove to be huge energy resources in future as solid gas hydrates.
He says the plates are moving northwards and the speed has reduced due to Eurasian plate, also it exerts tremendous amount of pressure as the rise in the Himalayas happens at the rate of 5mm per year. There are certain places, the central seismic gap, where earthquakes have not taken place in the last 200 years leading to the possibility of earthquakes in future. A well-coordinated program with Nepal and China needs to be undertaken to understand and probable forecasting of earthquakes. There is a high probability of an earthquake with magnitude 8, but there are lesser chances of an earthquake with magnitude 9, disaster like in Japan and Tsunami can be expected. But an earthquake of such intensity 9 needs a large area of 1000 km in length and 200 km in width which is not available due to transverse ridges. The earthquake of magnitude 8 still is not ruled out and hence there is need for making earthquake resistant infrastructure.
He says Himalaya has the largest snow and ice cover leading to change in glaciers and most of the glaciers are retreating but not at the same rate. Overall loss of glaciers in 15 years is about 16%, which is mainly due to warming. If the emission is controlled and is low that the glacier retreating can be 10.6% while the high emission can lead to 27% of retreating of glaciers. The Research Centre ‘Himansh’ at Chandra basin continuously measures the mass, energy and hydrological balances and entire glaciers are monitored every year between June and September. As a result, it has been found that at the glacier, Balasigri, no accumulation is happening and it is fed by avalanches only and thus it may retreat much faster than others. When glaciers retreat the lakes are formed. There are about 20,200 such lakes and about 200 lakes are very critical as their volume has increased by 26%, leading to increased risk of flood. International network is required to monitor such lakes and there is a need to develop an early warning system. On Tibetan plateau about 1.6 million sq. km. area is under permafrost with about 46,000 glaciers and the area has been reduced by 17%. Due to rapid industrial growth, there is an increase in the rate of snow and ice melting, which is further adding to global warming.
He explained that the rivers mainly depend on snow and glacier melting. The central region has winter snowfall and in eastern region the rainfall and snowfall together flourish the rivers, but the change in snow cover can drastically modify the water cycle, especially, that of the Indus. In Indus basin which is supporting almost 25% food crops in India and nearly 90% of food crops in Pakistan depend on it. The frequency of heavy rains has increased with warming and increase of atmospheric water vapor and such precipitation will keep increasing with the rising trend of western disturbance. This calls for the need to develop a warning system which does not depend only upon the rainfall but also considers other factors while predicting the rainfall. Talking about water resources and energy he focused on the dams that are being built for hydropower generation, which is considered to be clean development and subsides the carbon offset, though large dams cause hydrological and ecological damage. He suggested micro and mini hydropower generation.
He also focused on forests and biodiversity. He pointed out that the forest cover in Nepal is decreasing, Bhutan maintained its forest cover and in India there is an increase from 30-35%. Such decrease in forest cover in an area will not only affect that one nation but will have an effect in much larger areas, affecting globally. This has also led to an increase in forest fire by 40%.
Himalaya is also under stress due to conflict between India, Pakistan and China and the urbanization that is taking place. It requires an interdisciplinary approach and mechanism to understand the Himalaya environment, its role in earth system and international politics. He said no country can generate knowledge about the Himalaya alone, but international collaboration is needed and various services related to weather, climate, hazards for the country and neighbouring regions can be developed and also the issues of indigenous people need to be addressed.
He shared that he proposed the Himalayan Science Council in March 2013, but it may not be supported by China and Pakistan. So, a concept paper was prepared on Himalayan Science Council and plan of action in 2017. In 2019 an expert group recommended Himalayan Science Council to be established to promote scientific cooperation and to coordinate activities. He said we need to have international collaboration along with China and Pakistan to study the Himalaya together and have networking of scientific institutions to preserve the Himalaya system.
The attendees appreciated the session and there was discussion about how the policies can be enabled to cater all the issues being raised related to Himalaya. Shri Dharam Vir, former Chief Secretary of Haryana and President of SPSTI proposed a vote of thanks to the Speaker and the audience.