On a global scale some regions might be substantially stronger affected by future climate change than the European continent. Within the IMPACT2C project, the focus was set to West and East Africa, Bangladesh and the Maldives.
These IMPACT2C case study regions have been selected for a detailed study of potential consequences of a 2 ˚C global mean warming, because they reflect a wide range of sensitivities to future climate change. Large areas of western and eastern Africa are already characterized by a water shortage today. Bangladesh is subject to frequent flood events and may face substantial impacts due to global sea level rise, which is also the major threat for the low-lying islands of the Maldives.
For these non-European hotspot regions, the region-specific characteristics of projected changes in mean precipitation and mean temperature under a +2˚C world have been analysed in detail. Moreover, the atlas also shows the impacts of future sea level rise for Bangladesh and the Maldives.
For western Africa, the regional warming approximately corresponds to the global mean warming of +2°C. For precipitation, a modest increase of less than 10% in precipitation is projected for most of the region. As the expected increase in precipitation is not very large, a general risk of an increased water shortage persists, because increased temperatures might also lead to enhanced evapotranspiration.
For eastern Africa, the regional warming also corresponds to the global mean warming of +2°C, and is spatially rather uniform. For precipitation, a slight decrease (around 20 mm/year on average) in precipitation is projected over Ethiopia, however there is only a modest consensus of the analyzed models on the decrease. Across Somalia and also around Western Sudan, precipitation is projected to increase.
For Bangladesh, there is a close match between the magnitude of projected warming for the region and the magnitude of the projected global warming of +2°C on average, but with a more pronounced warming towards the northern parts. Precipitation is projected to increase all over the region, with a stronger increase in the southeastern part. With respect to coastal flooding, expected impacts are dependent on several factors – including subsidence and sea-level rise. However subsidence is highly variable and sea levels will continue to rise, even if the temperature rise would stabilize at +2°C.
Finally, over the Maldives, the projected temperature increase is below the global average (+1.4°C for the Maldives compared to +2°C globally). Over the whole Archipelago a substantial increase in rainfall is projected for a 2°C global mean warming, with a maximum increase at the latitude of Male with about 1/3 more rainfall than today. In the atlas section “social changes and sea-level rise in the Maldives”, these findings have been combined with other information and some initial conclusions on overtopping conditions and flood extents associated with +2°C warming could be drawn.
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