Climate and Biodiversity

Abstract

The Hindu Kush Himalayan (HKH) region is characterized by mountainous environments, having a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, especially during the global warming period. The rapid warming cause solid-state water (snow, ice, glacier, and permafrost) to shrink, leading to increase in meltwater, and there have been found more frequent incidences of flash floods, landslides, livestock diseases, and other disasters. Meanwhile, the HKH region is often referred to as the water towers of Asia as many high-altitude regions store their water in the form of snow and/or glacier, feeding ten major large rivers in Asia. Therefore, the impacts of climate change on water availability in these river basins have huge influences on the livelihood of a large number of population, especially in downstream regions. However, the scarcity of basic hydro-meteorological observations particularly in high-altitude regions of HKH limits rigorous analysis of climate change. The temperature in the HKH undergoes a significantly increasing trend, and the warming rate is greater than the global change. Thus, the elevation-dependent warming (EDW) is clear over the Tibetan PlateauTibetan plateau (China), and the warming has occurred at a greater rate at higher elevations. The exact driving mechanisms responsible for EDW need further investigation. Because of the great range of climate variability in the HKH region, it is possible here to make only very general comments about past, present, and future climate trends and variability. The degree of warming appears to increase with elevation, as observed in Tibet and NepalNepal, and warming is more pronounced in winter than in summer. Changes in precipitation have been observed throughout the region, but these are highly variable. The summer monsoon dominates the climate, lasting eight months (March–October) in the Eastern Himalayas, four months (June–September) in the Central Himalayas, and two months (July–August) in the Western Himalayas. The east–west variation is based on the dominance of different weather systems, which in turn causes the monsoon to weaken from east to west. The monsoon penetrates northwards along the Brahmaputra River into the southeast Tibetan PlateauTibetan plateau (China). Mountains are still facing enormous pressure from various drivers of global change, including climate change. Under the influence of climate change, mountains are likely to experience wide-ranging effects on the environment, biodiversity, and socio-economic conditions. Changes in the hydrological cycle may significantly change precipitation patterns leading to changes in river runoff and ultimately affecting hydrology and nutrient cycles along the river basins, including agricultural productivity and human wellbeing. Recent scientific understanding, led by the Intergovernmental Panel on Climate Change (IPCC), is that global climate change is happening and will present practical challenges for local ecosystems. These changes will impact everything from the natural landscape to human health, built infrastructure, and socio-economic conditions. The global community is currently trying to understand the nexus between climate change and mountain vulnerability, especially in the most remote and highest mountains of the world—the Hindu Kush Himalayas.