PREDICTING FUTURE TEMPERATURE AND PRECIPITATION OVER PAKISTAN IN THE 21ST CENTURY

Abstract

The objective of this study was to analyze projections of changes in mean annual temperature and precipitation over Pakistan for mid-century (2040–2069) and end century (2070–2099) time periods. An open source web tool namely “climate wizard” was used to obtain temperature and precipitation departures projected by three different GCMs under A1B, B1 and A2 emission scenarios. To ensure the maximum possible spatial coverage, a total of 16 climatic stations in Pakistan were selected. Results indicated a temperature departure in the range of 1.3-2.7°C for the mid century period, and a temperature departure in the range of 2.3-5.3°C for the end century period. Among different provinces of Pakistan, Gilgit Baltistan, Northern and Southern Punjab, Khyber Pakhtunkhwa and central Balochistan are likely to be subjected to greatest temperature rise in the coming decades. The projections of precipitation changes over Pakistan by different models show greater variability compared to temperature changes. An increase in precipitation in the range of (1-11%) was projected over Pakistan for the mid century. However, central Balochistan and southern Punjab showed negative precipitation departures ranging from -1 to-11%, thus increasing the likelihood of droughts in these regions. For the end century, positive precipitation departures were projected throughout the country, except Balochistan, Gilgit Baltistan and Southern Punjab, which showed negative departures of (-1 to -19%). With the projected rise in mean annual temperature through Pakistan, several sectors such as agriculture, energy, water supply and health will face serious challenges in the second half of the 21 st century. Therefore, preventive and remedial measures are required to minimize the impacts of projected warming by formulating long-term management and control policies for all sectors.