Future precipitation changes in Egypt under the 1.5 and 2.0°C global warming goals using CMIP6 multimodel ensemble

Rainfall projections for 1.5 and 2.0 degrees C warming can explain regional precipitation response to emission reductions under the Paris Agreements' goals. Assessment of such changes is vital for Egypt, a global climate change hotspot. The performance of 29 CMIP6 GCMs' hindcasts was evaluated according to their capability to replicate the spatial patterns of annual, winter, and summer precipitation for 1971-2014 to select a suitable GCM subset to form a robust multimodel ensemble (MME). The MME median was used to project precipitation and precipitation extremes of Egypt at the end of the century (2081-2100) for two shared socioeconomic pathways (SSP) scenarios, SSP1-1.9 and SSP1-2.6, representing 1.5 and 2.0 degrees C warming at the end of the present century, respectively. The results showed an increase in precipitation in the northern high precipitation region by 37% and 54% for SSP1-1.9 and SSP1-2.6, respectively, and a decrease in the southwestern low precipitation region by -35% for both scenarios. The projected increase would be mostly in winter and almost no change in summer. The projection of precipitation extremes revealed an increase in extreme precipitation amount in the northern coast between 0% and 14% and the longest dry spell over most of the country by 160%. The results indicate more heterogeneity in the spatial distribution in Egypt's precipitation, increasing extreme precipitation amount in some regions and dry spell length over the whole country. The results indicate a large increase in hydrological hazard susceptibility in Egypt, even if the global warming can be limited to 2 degrees C at the end of the century following the Paris Agreement.

Automated summary

This study assessed the performance of 29 climate models and projected potential changes in precipitation in Egypt. The results indicate a more complex distribution of precipitation in Egypt, with an increase in extreme precipitation events in some regions and longer dry spells throughout the country. This suggests that despite efforts to limit global warming according to the Paris Agreement, Egypt's susceptibility to hydrological hazards is likely to increase.