High Mountain Asia (HMA) is a scientific and geographical concept that defines a high-elevation region in central-south Asia, centered around the Tibetan Plateau. It encompasses numerous mountain ranges, including the Himalayas, Karakoram, Hindu Kush, and Tien Shan. The region was formed by the continental collision of the Indian Plate into the Eurasian Plate.
HMA is often nicknamed the "Third Pole" because it holds the world's largest reservoir of perennial glaciers and snow outside of the Earth's polar ice sheets. The formal scientific study of this concept gained prominence with the establishment of the NASA-funded High Mountain Asia Team (HiMAT), with the first project, HMA-1, running from 2016 to 2020. The problem it addresses is the critical need to understand how climate change is impacting the region's water resources.
HMA functions as a major water source, with its meltwaters and runoffs forming the headwaters of river systems that support the drinking water, food production, and hydropower needs of over 1.4 billion people in surrounding countries, including India, China, and Pakistan. Scientific monitoring of this mechanism involves advanced techniques like photogrammetry, laser altimetry, and satellite gravimetry. The data and tools produced by HiMAT are collected in the Glacier and Snow Melt Toolbox (GMELT).
The concept connects to the broader geopolitical idea of "The New Great Game" over resource dominance in the 21st century. While the core geography remains constant, the scientific focus has evolved, with the HiMAT effort moving from HMA-1 to the HMA-2 project, which began in late 2020. Recent studies have highlighted a coherent significant increasing trend in the occurrence of heatwaves across all regions in HMA between 1979–2018, underscoring the urgency of the research.