Can humanity deal with rising sea levels?

One of the five “mission areas” identified by the European Union as part of the Horizon Europe framework programme beginning in 2021 is “healthy oceans, seas, coastal and inland waters”. Prioritizing the sustainable use and management of ocean resources is understandable if we consider that, not only all the water on the planet produces half the oxygen we breath and has absorbed 26% of the CO2 emissions produced since the Industrial Revolution, but also, the oceans are home to the world’s richest biodiversity and contribute 16% of the animal protein we eat.

An OECD report also stresses the crucial role of marine ecosystems for humanity, as they provide social, economic and environmental benefits. Marine ecosystems are extremely varied and encompass not only oceans and seas but for example also mangroves and coral reefs. The pressures on these ecosystems from human activities has rapidly grown and are expected to rise. OECD concludes that 60% of the world’s major marine ecosystems have been degraded or are being used unsustainably. In a mere three decades, 20% of global mangroves and 19% of coral reefs have disappeared. Also, in 2013, 31% of fish stocks were estimated as fished at biologically unsustainable levels, compared to 10% in 1974.

These facts call for immediate action, such as the introduction and expansion of marine protected areas. As OECD notes, “MPAs can help ensure the sustainable provision of multiple other ecosystem services that are fundamental for human well-being, including for fisheries, coastal protection (buffering against storms and erosion), tourism and recreation”.

The mention of coastal protection is particularly interesting in light of a recent New York Times piece that went viral for concluding that by 2050 many more cities will have been erased by rising sea levels than expected. While the research on which the piece is based is sound, relying on artificial intelligence to improve standard satellite measurement techniques which struggled to differentiate the true ground level from the tops of trees or buildings, the conclusions drawn by the NYT appear to have been flawed.

For example, the NYT notes that by 2050 more than 20 million people in Vietnam, almost one-quarter of the population, live on land that will be inundated. Bjorn Lomborg, however, points out that the data for Vietnam, and the similar effects around the world that have been predicted, leave out two important aspects. First, that many literally have been living on the water for generations already, for example because it is an incredibly fertile environment; and second, that coastal defences are not considered. The latter point is indeed vital, and Lomborg correctly recalls that large parts of the Netherlands – including Schiphol, one of the world’s busiest airports – are below sea level. Lomborg does not downplay the importance of tackling climate change. However, even if predictions are correct that there will be an additional 40 million people living below sea level in 2050, bringing the global total to 150 million, he refers to research which suggests that almost all of them can be protected by installing an appropriate a costal defence infrastructure.

The dystopian scenario sketched by the NYT may therefore be counterproductive in helping the world’s poorest: instead of pushing policymakers towards adopting an excessively expensive agenda of CO2 reduction, efforts and funds could also be directed towards helping the affected areas by protecting them with simple infrastructure.

Edited by: Dr. Olivier Vonk