The effect of climate change on the maximum temperature in Southwest Iraq using HadCM3 and CanESM2 modelling

Abstract

In the twenty-first century, climate change has become a major environmental threat specifically for regions which are already dry. The identification and assessment of climate change in the future are therefore paramount for suitable environmental planning in order to adapt to and decrease its impact. In this research, changes in the maximum temperature in Iraq over the period 2020–2099, were generated by two general circulation GCM models, HadCM3 and CanESM2, based on emission scenarios A2, B2, RCP2.6, RCP4.5, and RCP 8.5. After checking the ability of the Statistical Downscaling Model (SDSM) to generate climatic data based on the period 1979 to 2018, the daily maximum temperature was downscaled for the period 2020–2099 in seven meteorological stations in Iraq. The results of the uncertainty analysis show the maximum temperature generation using the CanESM2 model with emission scenario RCP 2.6, having the best performance among all stations. The results also show an increase in maximum temperature of between 0.3 and 1.2 °C across all stations by the end of the twenty-first century. This increase in the maximum temperature impacts water resources due to increased evaporation from surface water, causing water scarcity. Changes in the maximum temperature show more of an increase using the HadCM3 model when compared with CanESM2, for all stations in Iraq.