Projected changes in thermal bioclimatic indicators over the Middle East and North Africa under Paris climate agreement

Thermal bioclimate is a defining factor of agricultural production, ecological condition, public health, and species distribution. This study aimed at assessing the possible changes in the Middle East and North African (MENA) thermal bioclimate for two shared socioeconomic pathways (SSPs), SSP1-1.9 and SSP1-2.6, representing a temperature rise restricted to 1.5 and 2.0 degrees C above the pre-industrial level at the end of the century. Therefore, the study explains the probable least change in bioclimate due to climate change and what might happen for a 0.5 degrees C temperature rise above the 1.5 degrees C addressed by Paris Climate Agreement. A multimodel ensemble of eight global climate models was employed for this purpose. The results indicated a 0.5 degrees C further increase in temperature above the 1.5 degrees C temperature rise threshold would cause a nearly 0.8 to 1.0 degrees C increase in temperature in some parts of MENA, indicating a faster than global average increase in temperature in the region for higher temperature rise scenarios. Climate change would cause a decrease in thermal seasonality by 2-6% over nearly 90% of the study area. The diurnal temperature would decrease by 0.1 to 0.4 degrees C over the entire south, while the annual temperature range would decrease by 0.5 to 1.5 degrees C over a large area in the north. This would cause a decrease in isothermality nearly by 1% over most areas. The area with decreasing isothermality would expand by almost 150% for a further temperature rise by 0.5 degrees C. The results indicate a substantial change in bioclimate in MENA for a minor temperature change.