Projected changes in the climate of Pakistan using IPCC AR5-based climate models

Abstract

Using an ensemble of 22 climate models from the 5th Annual Report of Intergovernmental Panel on Climate Change (IPCC AR5), the projected robustness and variability of temperature and precipitation for the data-sparse region of Pakistan is studied both on seasonal and annual time scales for the 21st century. The winter season in Pakistan is displaying ensemble-based spatially robust and progressively more relative warming in temperature under representative concentration pathway (RCP) 8.5 scenario as compared to RCP 4.5 scenario, both in the middle (2035−2064) and end (2070−2099) of 21st century projection periods. On the other hand, the ensemble-based relative changes in precipitation during the aforementioned two projected periods are spatially less robust. Most of the atmosphere–ocean general circulation models (AOGCMs) project a relative increase of 5−10% in annual precipitation in all the regions of Pakistan. On a seasonal time scale, most AOGCMs project a relative precipitation decrease (increase) during winter (summer) in central and in southern (central and northern) Pakistan. All the AOGCMs under both RCPs project an increase in temperature in all Pakistan, northern Pakistan, and southern Pakistan on annual, winter, and summer time scales.