Projected changes in surface air temperature over Pakistan under bias-constrained CMIP6 models.

Pakistan is facing an increasing challenge of extreme climate-related events with accelerating global warming. Accurate simulation and reliable projection of change in temperature properties under climate change is important for developing appropriate adaptation strategies. The present study assessed the performance of bias-corrected CMIP6 models in representing seasonal and annual surface air temperatures (tas) over Pakistan. The results reveal that the majority of models reasonably capture the dominant features of the spatial variations in observed temperature, despite the warm (cold) bias over northern (southern) parts of Pakistan. However, employing the quantile mapping algorithm significantly reduced biases in models. The projections in near-future (2015–2039), mid-century (2040–2069), and late-century (2070–2099) temperatures under SSP2-4.5 and SSP5-8.5 scenarios revealed diverse changes. Significant warming tendencies under SSP5-8.5 scenarios in winter (1.92 °C/decade), annual (0.85 °C/decade), and summer (0.84 °C/decade) are expected in the twenty-first century. The late-century winters project strong mean changes of 5.2 °C under SSP5-8.5, with mean changes reaching nearly 3.0 to 6.5 °C in northern parts of the country. Late-century summers projected mean changes of 4.3 °C under SSP5-8.5, with the strongest change of 2.5–6.1 °C exhibited at the northern and southwestern parts. The late-century annual temperature may show changes at 5.0 °C under SSP5.8–5, especially over northwestern regions projected to exhibit mean changes of 5.0 to 5.5 °C. The study highlights the robust warming towards the end of the century and thus calls for urgent demand to regulate the emissions toward reducing impacts in the future over the study region. [ABSTRACT FROM AUTHOR]