Projection of temperature and precipitation under climate change in Tabriz, Iran

The present study evaluated the precipitation and temperature variations under CMIP5 and CMIP6 reports of the intergovernmental panel on climate change (IPCC) for a future period (2015–2100) in Tabriz City, Northwest Iran. To accomplish this, several general circulation models (GCMs), including BNU-ESM, CCSM4, EC-EARTH, and GFDL-CM3 from CMIP5 and BCC-CSM2-MR, CanESM5, CESM2, and HadGEM3-GC31-LL from CMIP6 were employed. These GCMs were implemented under various climate change scenarios, namely, representative concentration pathways (RCP) RCP2.6, RCP4.5, and RCP8.5 from CMIP5 and shared socioeconomic pathways (SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 from CMIP6. The results demonstrated that temperature in all months and scenarios would increase. It is projected that the average temperature from 12.61 °C in the base period will increase to 13.52 °C, 14.33 °C, and 14.91 °C in RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. In comparison, the temperature will experience a dramatic increase with 15.42 °C, 16.16 °C, and 17.53 °C for SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios, respectively. The projection of precipitation showed that the precipitation would decrease except for some months. Results showed that the average precipitation would decrease by 1.27 mm in RCP2.6, 1.44 mm in RCP4.5, and 2.33 mm in RCP8.5, while the amount of decline in precipitation is 0.89 mm, 1.69 mm, and 2.21 mm for SSP1-2.6, SSP2-4.5, and SSP5-8.5, respectively. It was found that, in terms of temperature, variations would be dramatic under CMIP6.