Rainfall: Future scenarios project a 5–25% increase in summer rainfall over most of the basin up until 2050. According to the wettest scenario (RCP 8.5), the increase could be more than 25%, especially in the northern and far-western parts of the basin. In winter, projections show an increase over the main mountain range. This winter increase is expected to range from 5–25%. However, the southwest part and central northern part show decreases in winter precipitation of up to 25% for both scenarios. Overall, RCP 4.5 and RCP 8.5 project an increase of 10.5% and 9.5%, respectively, for the monsoon season. Temperature: Both climate change scenarios show an increase of 1–3°C across the Brahmaputra basin in summer. The RCP 8.5 scenario shows a slightly larger area that will experience a 2–3°C increase. The increase in winter temperature is similar, but occurs over larger areas and with stronger warming (with an increase of more than 3°C in some areas), particularly for the RCP 8.5 scenario. Projections show that winter and summer warming is greater in the north where the increase is mostly more than 2°C.
From collection: The Himalayan Climate and Water Atlas