The Himalayas is the source of major transboundary rivers in South Asia. The rise in temperature of Himalayas in recent years due to global climate change has been much higher than the global average. The shifts in rainfall pattern and increasing extreme weather events have increased floods and droughts in the region. The rising sea-level is increasingly putting Delta areas at high risk and enhance the social tension. South Asian countries sharing rivers like Indus, Ganges, and Brahmaputra, which emerge in the Himalayas are also witnessing changing relationships and changing economies in the face of climate change. The emergence of China as a global power has dramatically challenged India’s age-old domination in these river basins. The presentation aims to address the impact of these changes on water sharing mechanisms in the South Asian region and implications for policy making in development and security sectors.