6.3. Research recommendations and outlook for regional co-operation 6.3.1. Advancements in climate modelling While future temperature projections appear to be quite robust, this is generally not the case for precipitation. Several factors contribute to modelling uncertainties, including 1) the very local nature of some rainfall events, 2) misrepresentation of orography and coastlines due to low model resolution and 3) sensitivity of modelled precipitation to the parametrisation methods of sub-grid-scale processes that contribute to rainfall generation (e.g. convection and cloud microphysics processes) (Zittis et al., 2017; Alpert et al., 2021). An increase in the vertical and horizontal resolution of climate models (global and regional) is a step forward, yet implies access to substantial computational resources. Improvements in the parameterisation schemes for physical processes, also considering the regional peculiarities and in-situ measurements of atmospheric properties, are also essential. Most regional modelling efforts in the EMME region focus on the atmospheric component of the climate system. Additional components such as oceans, land and atmospheric chemistry processes are not yet sufficiently considered. For example, ocean properties (e.g. sea levels and sea surface temperatures) are prescribed, while vegetation and landuse components, including vegetation fires, are based on present-day inventories that are not dynamic (i.e. they are static over time). Furthermore, atmospheric chemistry components that have a strong impact on the regional climate (e.g. dust and other aerosols) are either prescribed or not considered. The consideration of additional modelling components (ocean circulation, dynamic vegetation and atmospheric chemistry) could eventually lead to regional earth system models. These could generate climate projections of increased accuracy and validity in representing mean climate conditions and extreme events of high societal impact. However, this type of coupled regional climate modelling implies substantial computational resources, multidisciplinary collaborations and expertise that is mostly not available in the region. For example, while there are significant advancements in the coupled atmosphere-ocean modelling for the Mediterranean, mainly through the Med-CORDEX initiative11 (Ruti et al., 2016; Soto-Navarro et al., 2020), such regional initiatives do not exist for the Red Sea and the Gulf region. The EMME region is characterised by rapid urbanisation, and population projections suggest this trend will intensify in the future. Dubai’s dramatic urban evolution in just two decades is a case in point (Elhacham and Alpert, 2021). The combined effects of increased population density, anthropogenic climate warming, the urban heat island effect and poor air quality are expected to introduce additional challenges. 11. https://www.medcordex.eu/.
6. Challenges and recommendations | 55
Physical-Basis-txt-LJ-SF2.indd 55
5/19/22 12:50 PM
