Mountain Adaptation Outlook Series - Synthesis Report

precipitation change can also mask some important changes: all mountain regions have experienced changing rainfall seasonality and/or rainfall intensity in one form or another, even if annual rainfall has not changed. Future projections of precipitation are also less clear, especially regarding annual average precipitation, so any conclusions should be approached with caution. Precipitation is expected to decrease in the Western Balkans, and increase in East Africa, Central Asia and the Hindu Kush Himalaya, while no large annual change is expected at all in the Andes. In the Carpathians and South Caucasus precipitation is expected to have mixed trends, including less rainfall during summer and more during winter. However, almost all regions will experience more intense rainfall (i.e., more rain falling per event), translating into more floods. This is true even if certain regions are expected to get drier or experience more prolonged drought periods. Even in the Western Balkans, where extreme precipitation is not projected to increase, more floods are predicted because of more precipitation falling during winter. The projections of more intense rainfall across mountain regions are in line with global trends where almost all parts of the globe are projected to experience more intense rainfall. There is general agreement amongst climate models that the future will bring an increase in heavy precipitation across most of the world, including in the mountain regions covered by the Outlooks (bottom map). There is much less agreement amongst models about trends in future average annual precipitation (top map), especially for mid- latitude areas (shown by the noticeably fewer dots on the map). Note: RCP refers to representative concentration pathway. RCP 8.5 assumes more or less unabated increasing gas emissions over time and absence of any climate mitigation measures.

Meadow outside Stepanavan, Armenia

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