Editing IPCC:AR6/WGII/Chapter-9 (section)

===== 9.9.4.1.1 Flooding =====

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Continuing current population and GDP growth trends, the extent of urban land exposed to high-frequency flooding is projected to increase around 270% in north Africa, 800% in southern Africa, and 2600% in mid-latitude Africa by 2030 when compared to 2000, without considering climate change ( [[#Güneralp--2015|Güneralp et al., 2015]] ). In addition, global warming is projected to increase frequency and magnitude of river floods in east, central and west Africa ( [[#Alfieri--2017|Alfieri et al., 2017]] ; [[#Gu--2020|Gu et al., 2020]] ; [[#Kam--2021|Kam et al., 2021]] ). On average, across large African river basins, the frequency of flood events with a current return period of 100 years is projected to increase to 1 in 40 years at 1.5°C and 2°C global warming, and 1 in 21 years at 4°C warming, with Egypt, Nigeria, Sudan and the Democratic Republic of Congo in the top 20 countries globally for projected damages ( [[#Alfieri--2017|Alfieri et al., 2017]] ). Compared to population in 2000, human displacement due to river flooding in sub-Saharan Africa is projected to increase 600% by 2066–2096 with moderate-to-high population growth and 2.6°C global warming, with risk reducing to a 200% increase for low population growth and 1.6°C global warming ( [[#Kam--2021|Kam et al., 2021]] ).

Urban population exposure to tropical cyclone hazards in southeastern Africa, in particular Mozambique, is projected to increase due to the intensification of cyclones and their extended duration associated with warmer sea surface temperatures ( [[#Fitchett--2018|Fitchett, 2018]] ; [[#Vidya--2020|Vidya et al., 2020]] ). Urban damage assessment based on a 10-year flood protection level for Accra, Ghana, shows that without flood protection, there is a 10% probability of a flood occurring annually which could cause USD 98.5 million urban damage, affect GDP by USD 50.3 million and affect 34,000 people ( [[#Asumadu-Sarkodie--2015|Asumadu-Sarkodie et al., 2015]] ). Many urban households and Africa’s growing assets could therefore be exposed to increased flooding ( [[#IPCC--2018b|IPCC, 2018b]] ).

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