Trends, forecasting and adaptation strategies of climate change in the middle and west regions of Iraq

Climate change has placed considerable pressure on the residential environment, agricultural, and water supplies in different areas of the world, especially arid places such as Iraq. Iraq is one of the five most vulnerable countries in the world to climate change, where it has been encountering extremes heat waves during the most recent decades resulted in drought, desertification, and rivers dried up, which led to thousands of hectares to turn dry and yellow. This study aims to investigate the trends of climate change in the middle and western regions of Iraq and future expectations. The daily maximum temperature, minimum temperature, and precipitation are downscaled using the Long Ashton Research Station Weather Generator (LARS-WG) model. Five General Circulation Models (GCMs) from Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed for three future periods: the near future (2021-2040), medium future (2051-2070), and far future (2081-2100), based on two scenarios of the Representative Concentration Pathways (RCP4.5 and RCP8.5) for four selected meteorological stations representing the study area. The outcomes of the calibration and validation of the model supported its skill and reliability to downscale precipitation and temperature time series for statistical indices (R2, RMSE and MBE) ranging between (0.894-0.998), (0.1270-1.9274) and (- 0.6158 to 0.0008), respectively. The results showed that the average minimum and maximum annual temperatures will increase at all selected stations across the three future periods by between 0.94 and 4.98 degrees C by the end of the twenty-first century. Annual changes in precipitation tend generally towards increase for the study area by average (6.09-14.31%) for RCP4.5 and (11.25-20.97%) for RCP8.5 Compared to the historical data (1990-2020). These findings can contribute to become more acquainted with the effects of climate change on the environment and encourage managers and planners to come up with plans for mitigating and adapting to these effects. They can also serve as a guide for future management of water and agricultural resources in the study region. The LARS-WG model effectively downscaled daily temperatures and precipitation in the middle and west regions of Iraq.A steady temperature increase in the current century in the study area between 0.94 and 4.98 degrees C.Future precipitation patterns vary, ranging from + 6.09 to + 14.31% for RCP4.5 and + 11.25 to + 20.97% for RCP8.5.