The first comprehensive study of African cultural and natural heritage sites reveals the risks posed by rising sea levels and erosion.
A global team of climate risk and heritage experts, including Prof Joanne Clarke of the School of Art, Media, and American Studies, identified and mapped the physical boundaries of 284 African coastal heritage sites, over one year. They then modelled the exposure of each site at future global warming scenarios.
The research, 'African heritage sites threatened as sea-level rise accelerates’, is published today in Nature Climate Change.
Calculating the predicted rise in global temperatures based on projected carbon emissions, the team was able to estimate the effect of extreme sea-level events (a combination of higher sea level, wave action, tides, storm surges, and erosion), and thus how and where those would occur around Africa.
The researchers found 56 sites (20 per cent) are at risk from a one-in-100-year extreme sea-level event. These endangered sites include the iconic ruins of Tipasa in Algeria and the North Sinai archaeological Sites Zone of Egypt.
At least 151 natural and 40 cultural sites will be exposed to the 100-year event from 2050 onwards, regardless of the warming scenario. The number of exposed sites is projected to more than triple to 191 sites with moderate emissions projections and 198 under high emissions projections.
Prof Clarke, who co-authored the paper, said: “Small island heritage sites are especially at risk. For example, Aldabra Atoll, the world's second-largest coral atoll, and The Gambia’s Kunta Kinteh Island could both see significant amounts of their extent exposed by 2100 under high emissions, raising questions of their survivability under climate change.
“This is very concerning because none of these countries currently demonstrate adequate management or adaptive capacity to anticipate or establish heritage protections commensurate with the severity of these hazards.”
The research highlights the importance of climate change adaptation and mitigation responses to protect and reduce the exposure of these heritage sites.
Prof Roshanka Ranasinghe of IHE Delft Institute for Water Education, also co-authored the paper.
Prof Ranasinghe said: “If climate change mitigation successfully reduces greenhouse gas emissions from a high-emissions pathway to a moderate emissions pathway, by 2050 the number of highly exposed sites can be reduced by 25 per cent. This would be a significant saving in terms of loss and damage from climate change.”
The research was coordinated Dr Nicholas Simpson from the University of Cape Town, who said it will help to prioritise sites at risk and highlight the need for immediate protective action for African heritage sites.
Dr Simpson said several countries are projected to have all their coastal heritage sites exposed to 100-year coastal extreme events by the end of the century, regardless of how much global temperatures rise. These include Cameroon, Republic of the Congo, Djibouti, Western Sahara, Libya, Mozambique, Mauritania, and Namibia. Under the worst-case scenario, this is also true for Côte d'Ivoire, Cabo Verde, Sudan and Tanzania.
Dr Simpson said: “Urgent climate change adaptation for heritage sites in Africa includes improving governance and management approaches; site-specific vulnerability assessments; exposure monitoring; and protection strategies including ecosystem-based adaptation.”
'African heritage sites threatened as sea-level rise accelerates’ is published in Nature Climate Change on 10 February 2022.