Predicting long-term climate changes in Iraq

Changes in air temperature have a significant impact in Iraq due to global climate change. The objective of this study is to project future trends of air temperature in Iraq. In this study, the future air temperature was projected for 2025, 2050, 2075 and 2100 from the CCSM4 climate model belong to CMIP5 under RCP2.6, RCP4.5, RCP6.0 and RCP8.5 scenario for Iraq. The historical observed air temperature data (1950 – 2014) acted as referenced as the mean air temperature data obtained from 18 meteorological stations. Statistical downscaling has implemented. The model outputs were calibrated by using around 80% of the observed historical and model historical data. After that, it proved a significant performance of a statistical downscaling process for simulation air temperature for future periods. The results revealed that the mean air temperature would increase under the four RCPs scenarios with different levels. The lower increase rate belongs to the RCP2.6 scenario, the increase rate is expected to be (0.5-0.8 °C) above the observed historical level. However, the RCP8.5 has the highest rate at (4.1 -6 °C) while, the RCP4.5 and RCP6.5 have (1-2 °C) and (2-4 °C) respectively. On the other hand, the temperature expands direction is from the south toward central, west and north of Iraq.