The Indus River is one of the longest rivers in Asia, originating in the Tibetan Plateau near Lake Mansarovar. It flows through the Ladakh region of India and then across the entire length of Pakistan into the Arabian Sea. The Indus is the critical backbone of Pakistan’s economy and food security, as it supports the largest contiguous irrigation system in the world. Historically, it was the site of the ancient Indus Valley Civilization, one of the world's first urban societies. The river is fed by the melting glaciers of the Himalayas, Karakoram, and Hindu Kush ranges, making it highly sensitive to climate change. As temperatures rise, the initial increase in glacial melt provides more water, but long-term loss of glacier volume poses a severe threat to the billions of people who rely on the river for agriculture and drinking water.