Climate change projections for Diamer Division in lesser Himalayas using multi-global climate model ensemble.

Abstract

Pakistan, like many other regions around the world, is experiencing the impacts of climate change, particularly in its northern region. These changes have adverse impacts on ecosystems and biodiversity. Herein, we have investigated future projections of temperature and precipitation trends for three periods historical (HT = 1975-2005), near-term (NT = 2010-2029), and mid-term (MT = 2030-2050) using climate model intercomparison projects along with global climate models (GCMs) including RCP4.5 and RCP8.5. The historical records spanning from 1975 to 2005 reveal that the Chilas region has a notable rise of 8 °C in maximum temperature (T_max), whereas the Astore district exhibited a trend of decreasing temperatures. When examining the projected temperature trends using GCMs (RCP4.5 and RCP8.5), the Chilas region is predicted to undergo a further increase of 6 °C in T_max. In contrast, the Babusar region is projected to observe a significant decrease of 2 °C for the period between 2010 and 2050. Additionally, the precipitation results obtained from historical-based analysis for the period 1975 to 2005 indicated that the Babusar area exhibited increased precipitation patterns to 20 mm on an annual basis. Similarly, the Astore region has the most significant decline in precipitation, with a reduction of 40 mm annually. The predicted precipitation patterns for the period between 2010 and 2050 under the RCP8.5 revealed that the Babusar region has maximum precipitation (25 mm). Conversely, the Astore region exhibited reduced precipitation patterns, recording minimum precipitation (40 mm). In the results from RCP4.5, the precipitation showed a similar pattern with a maximum of 35 mm and a minimum of 15 mm in the Babusar and Astore, respectively. The region's glaciers, snow cover, and land use systems are deteriorated by these changes in temperature and precipitation patterns. The increased winter and decreased summer precipitation under varied temperatures and precipitation cause land degradation, forest, and water resources. The cumulative impacts result in individuals experiencing poverty and raising concerns about the region's long-term viability.