ESTIMATING THE IMPACT OF CLIMATE CHANGE ON DROUGHT TRENDS AND ITS FUTURE PROJECTIONS OVER PUNJAB, PAKISTAN

Abstract

Climate change is unequivocally altering natural systems and impacts on droughtprone regions of Pakistan. Extreme climate often has a substantial impact on agricultural production. The Punjab province is the primary food production region of Pakistan. Over time it has become increasingly sensitive to alternating extremes like droughts and floods. The current study provides an outlook of Coupled Model Intercomparison Project Phase 5 (CMIP5) in simulating climate extremes indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) for historical (1850-2005) and future periods (2020-2100) under two representative concentration pathways (RCPs) 4.5 and 8.5 across Punjab districts. Changes generally present relatively larger magnitudes under RCP8.5 than RCP4.5. Projected ensemble results show a significant increase in summer days over Rajanpur and DG Khan districts. Additionally, significant increases in warmest days and nights are seen widespread over central Punjab districts. The precipitation related indices are reported to significantly increase over the district of Narowal. Meanwhile, the districts of the Western belt are likely to experience more drought events with increasingly warming temperatures. The study findings indicate that the projections of precipitationbased indices are closer to historical patterns with smaller variability and changes in the future period, while temperature-related extreme indices show a significant shift and increases along with the projections. It would result in drought frequencies to recur with similar patterns of the historical period, but with augmented warmer climate in the RCPs forced future climate over the Punjab province. This study provides complementary information on climate extremes over Punjab province for local decision-makers to incorporate into policymaking, disaster management, and infrastructure planning.