Together, the mammoth structures proposed by scientists would completely enclose the North Sea and offer protection for tens of millions of Europeans threatened by rising sea levels caused by climate change.
The scientists behind the proposal, outlined in a paper published on Thursday in the American Journal of Meteorology, said that the scale of the project — which exists only in the broadest outlines at this point — reflected the urgency of the crisis.
“See this as a warning,” said one of the authors, Sjoerd Groeskamp of the Royal Netherlands Institute for Sea Research. “What we’re saying is: Here’s a plan, a plan we don’t want. But if we end up needing it, then it’s technically and financially feasible.”
The project would be one of the largest engineering feats ever attempted on the planet and would cost anywhere from $250 billion to $550 billion, according to the proposal — a cost the authors suggest could be covered by more than a dozen Northern European countries that would be protected by the barrier.
Some experts expressed doubt that damming the North Sea was the best solution for dealing with rising sea levels.
“My initial reaction is skepticism,” said Craig Goff, who has been a dam safety engineer in Britain for about 20 years. “I suspect that it would be cheaper and quicker to build defenses along the coastline of Europe than to build dam structures across the North Sea.”
Even the scientists behind the proposal acknowledge that attempting to dam the entire North Sea is not an ideal solution.
Much better, they said, would be for the proposal to serve as an alarm, vividly illustrating the kind of drastic action that might become necessary if global leaders cannot find a way to address climate change.
“It might be impossible to truly fathom the magnitude of the threat” posed by rising sea levels, the scientists wrote. “However, conceptualizing the scale of the solutions required to protect ourselves against global-mean sea level rise aids in our ability to acknowledge and understand the threat that sea level rise poses.”
The other co-author of the paper, Joakim Kjellsson, a Swedish professor at the Helmholtz Centre for Ocean Research in Kiel, Germany, said that no official proposal had been made to the nations that would be protected by the barrier.
“In the end, we came to realize it’s such an extreme solution that it would be much better and much less dramatic to reduce our CO2 emissions and curb global warming so that we don’t need these kind of things,” he said in an interview.
If carbon pollution continues to grow, sea level rise by 2100 could exceed 40 inches (1 meter), Groeskamp said.
If nothing changes, Kjellsson said, millions of people will be forced from their homes — effectively becoming climate refugees. Even today, coastal cities such as San Francisco and Manila are faced with the consequences of sea level rise.