A plethora of recent studies have sought to unravel the consequences of unmitigated warming across the lofty mountain ranges of the Hindu Kush Himalayan mountains.
Often referred to as the ‘Third Pole’, the region extends from the Pamir-Hindu Kush Mountain ranges in the west to the Hengduan mountains in the east and encompasses the Tibetan Plateau and surrounding areas between the Tienshan and Qilian mountains to the north and the Himalayas in the south.
These ‘Asian Water Towers’ contain the largest mass of ice outside of the polar ice caps and provides freshwater resources to more than two billion people in three of the five most populous nations in China, India and Pakistan.
With an area of more than five million square kilometers, the Third Pole regulates the climate, protects biodiversity and is socioeconomically important for the densely populated countries of South Asia, China and Tajikistan.
The recently published ‘A Scientific Assessment of the Third Pole Environment’ adds to the discourse with a comprehensive documentation of the environmental changes in the region.
For the first time, the report outlines the collective understanding from interdisciplinary research on four key areas: climate, freshwater bodies, ecosystems and biodiversity, and human impact on the environment, over the past 2000 years.
The data has indicated that current warming started in the late 19th century but accelerated in the 20th century, with this century becoming the warmest in the past 2000 years.
Similarly, the recent episodes of precipitation increase began in the 20th century and continues till date, with both the warming and wetting trends are confirmed by the observational data across the Third Pole. Across the region, there are observed seasonal and regional differences with amplified warming in higher elevations.
The consequences of variations in temperature and precipitation are visible as glacier area and mass have decreased in past decades, with more observed loss along the Himalayas than other areas of the Third Pole. Such variations have also resulted in an increase of natural hazards largely associated with cryosphere in recent years and there are indications of an increase in risks that might be associated with the changing climate in the future.
Expectedly, the assessment has found that snow cover depth, area and duration have decreased in recent decades. River discharge has also shown an increasing trend in most of the rivers across the Third Pole over the past decades. The variations in discharge are closely linked to changes in precipitation and glacial melt runoff contributions.
The projections for increase in air temperatures across the Third Pole region vary between 1.4 to 5.6°C relative to the 1995–2014 period by 2100. Similarly, precipitation is expected to increase by 6-15 percent, with warmer and wetter conditions contributing to the rapid decrease in glacial mass in most areas.
The worst affected Eastern Himalayan region is projected to lose two thirds of the present glacial mass by 2100. Consequences include significant changes in the seasonality of river discharge. In glacier-fed river basins, rise in future runoff will be followed by steady decline because of glacier shrinkage, with cascading impacts on ecosystems and biodiversity.
Earlier studies had also pointed out the likelihood of future water scarcity in the Third Pole region. A pioneering data-based index of ‘hydro-political’ issues in areas with a history of ‘transboundary water resources,’ had in September 2018 listed the Ganges-Brahmaputra basin among the five global hotspots where ‘water wars’ are likely to happen in the future.
The Hindu Kush Himalaya Assessment Report published in 2019 corroborated the projections of the 2014 Intergovernmental Panel on Climate Change report regarding glacial loss in the Himalayas. The region has already warmed by 1.3 C and some scientists believe that 40 percent of the glaciers in the Tibetan plateau could disappear by 2050 with implications on the overall water, energy, and food security, the report stated, sounding the alarm.
The new assessment has revealed that human activities outside the Third Pole, including air pollutant emissions such as those of black carbon, heavy metal, and persistent organic pollutants, are negatively affecting the environment in the higher altitudes. Increasing atmospheric pollution from surrounding countries is not only having a negative impact on human health in the mountains, but also contributes to the glacier melt.
The Third Pole region is one of the most biologically diverse and remains comparatively less affected with a much lower rate of species extinction than the global average. Some species show a positive trend in populations due to successful conservation efforts, the report noted. Suggested interventions include a biodiversity baseline data, increased cross-border conservation efforts, community protection awareness, improvement of monitoring & management, creation of an alarm system to alert against introduced species, and efforts to reduce the ecological impacts of climate change.
The assessment has documented changes in the type of forest areas, from primary forests to secondary types across the Third Pole. It also pointed out ecosystem changes with earlier starts to the growing season, the expansion of vegetation coverage and an increase in ecosystem productivity. Change in vegetation will affect different species in different ways, with increased extinction threats for narrow range species requiring conservation efforts along with evidence-based management options.
As the highest ecosystem in the world with 14 of the highest mountain peaks, the Third Pole region provides freshwater to more than 12,000 lakes and more than 10 river systems. With vast coverage, varied and complex ecosystems, the region is significant in terms of climate regulation, hydrological cycle, and environmental processes.
The assessment found that these fragile highland ecosystems are witnessing a higher rate of warming than the global average, resulting in faster glacier melt and increased frequency of ice collapse and glacial lake outburst floods. This environmental change is directly impacting the stability of the Asian water towers, thus threatening the ecosystem, biodiversity, and livelihood of people.
Better understanding of the science behind the warming climate and its impact on ecosystem, biodiversity and livelihood is necessary for informed mitigation and adaptation policies for regional sustainability.
[Images from different sources]
[Writer Rituraj Phukan is the Founder, Indigenous People’s Climate Justice Forum; National Coordinator for Biodiversity, The Climate Reality Project India ; National Coordinator, Citizens Climate International; COO, Walk For Water; Secretary General, Green Guard Nature Organization ; Ambassador, European Climate Pact; Member, IUCN Wilderness Specialist Group; Commission Member – IUCN WCPA Climate Change, IUCN WCPA Connectivity Conservation, IUCN WCPA Indigenous People and Protected Areas Specialist Groups, IUCN WCPA South Asia Region and IUCN WCPA-SSC Invasive Alien Species Task Force; Assam Coordinator, Kids For Tigers, the Sanctuary Tiger Programme; Associate Editor, Igniting Minds; Member, International Antarctic Expedition 2013; Climate Force Arctic 2019 ; Ambassador, Marine Arctic Peace Sanctuary]
Mahabahu.com is an Online Magazine with collection of premium Assamese and English articles and posts with cultural base and modern thinking. You can send your articles to firstname.lastname@example.org / email@example.com ( For Assamese article, Unicode font is necessary)