African heritage sites threatened as sea-level rise accelerates

Abstract

The African coast contains heritage sites of ‘Outstanding Universal Value’ that face increasing risk from anthropogenic climate change. Here, we generated a database of 213 natural and 71 cultural African heritage sites to assess exposure to coastal flooding and erosion under moderate (RCP 4.5) and high (RCP 8.5) greenhouse gas emission scenarios. Currently, 56 sites (20%) are at risk from a 1-in-100-year coastal extreme event, including the iconic ruins of Tipasa (Algeria) and the North Sinai Archaeological Sites Zone (Egypt). By 2050, the number of exposed sites is projected to more than triple, reaching almost 200 sites under high emissions. Emissions mitigation from RCP 8.5 to RCP 4.5 reduces the number of very highly exposed sites by 25%. These findings highlight the urgent need for increased climate change adaptation for heritage sites in Africa, including governance and management approaches, site-specific vulnerability assessments, exposure monitoring, and protection strategies.

Coastal Zone Changes in West Africa: Challenges and Opportunities for Satellite Earth Observations

“…This could have dramatic consequences for some coastal areas located just above current sea level. Major coastal cities and historical heritage in the region are at great risk (Ouikotan 2017;Vousdoukas et al 2022). Saltwater intrusion into coastal aquifers will be more frequent and could gradually render aquifers unsuitable for consumption and agriculture.…”

“…A major challenge in the coming decades will be to predict how coasts (land, sea, and ecosystems) will evolve under the effects of global change, especially in low-lying and urbanized West Africa, which exposes it disproportionately (Oppenheimer et al 2019;Almar et al 2021a;Vousdoukas et al 2022). Descriptive and predictive models typically rely on numerous historical observations, making their application difficult in regions such as West Africa due to the lack of detailed information.…”

The evolving landscape of sea-level rise science from 1990 to 2021

“…A growing body of literature indicates that sea-level rise (SLR) threatens low-lying coastal and estuarine zones worldwide 5 , which will have nearly 1 billion inhabitants by 2030 6 , through a range of hazards and impacts including more frequent and/or intense coastal ooding 7, 8, 9, 10 , loss of habitats/ecosystems 11,12 , including islands 13,14 , and coral reefs 15 , coastal erosion and shoreline changes 16,17 , and salinisation of surface water and groundwater 18,19,20 . These hazards/impacts, in turn, can damage economic assets, urban/coastal infrastructure and coastal tourism 21,22,23,24,25 , in uence and induce human migration 26,27 , impact the livelihoods and safety of vulnerable coastal populations 28,29 , threaten heritage sites 30,31 , and even jeopardise renewable energy plans 32,33 .…”

“…A growing body of literature indicates that sea-level rise (SLR) threatens low-lying coastal and estuarine zones worldwide 5 , which will have nearly 1 billion inhabitants by 2030 6 , through a range of hazards and impacts including more frequent and/or intense coastal ooding 7, 8, 9, 10 , loss of habitats/ecosystems 11,12 , including islands 13,14 , and coral reefs 15 , coastal erosion and shoreline changes 16,17 , and salinisation of surface water and groundwater 18,19,20 . These hazards/impacts, in turn, can damage economic assets, urban/coastal infrastructure and coastal tourism 21,22,23,24,25 , in uence and induce human migration 26,27 , impact the livelihoods and safety of vulnerable coastal populations 28,29 , threaten heritage sites 30,31 , and even jeopardise renewable energy plans 32,33 .To adapt to these growing risks, governments, industries, and communities are increasingly working collaboratively through integrated, multidimensional management schemes that cross the boundaries of natural sciences, social sciences, and engineering 34 . Research on SLR science has increased exponentially, as re ected by the number of publications reviewed and cited in the periodic Intergovernmental Panel on Climate Change (IPCC) reviews.…”

Climate change, coastal built heritage, and critical challenges facing the heritage law frameworks of the United States, United Kingdom, and France

“…This shifting earth and rising water negatively affects the integrity of numerous coastal historic structures and sites across the world. Easter Island, with its hundreds of giant stone anthropomorphic statues (Moai), is eroding (Casey and Haner 2018); the ruins of ancient Carthage may soon slip into the sea (Vousdoukas et al 2022); and unprecedented floods in historic downtown Annapolis, Maryland, which boasts the United States' largest collection of eighteenth century colonial buildings, allowed kayakers to paddle along roadways (Geiling 2014).…”