Key Message: The Indus, Ganges and Brahmaputra river basins are extremely susceptible to temperature increase. Under a 1.5 °C global warming scenario, these river basins would warm up by more than 2 °C on average by the end of this century. At higher altitudes this warming will be even more marked, due to elevation dependent warming. A 2 °C global warming scenario could lead to a warming of around 2.7 °C in these glaciated river basins. Currently, more likely climate change scenarios, specific for these river basins, suggest regional temperature increases between 3.5 and 6 °C by 2100. The majority of the projections also indicate overall wetter conditions in the future and increases in extreme precipitation events. This will lead to significant losses in glacier volume, from 36 to 64%, depending on the warming scenario, and impact timing of water flows and water availability.