A new study published in the journal Nature Climate Change reveals that human-driven sea level rise has dramatically increased the frequency of extreme coastal flooding events worldwide. Researchers found that events with a 1% annual chance of occurring are now, on average, about 12 times more likely than they were historically.
The study, which analyzed tide gauge records from over 100 sites and climate modeling from 1900 to 2005, attributes about a fourfold increase directly to human-caused climate change. Lead author Sönke Dangendorf, an associate professor at Tulane University, noted that greenhouse gas emissions from burning fossil fuels are the dominant factor, especially since the 1970s.
A separate study in Science Advances found that climate change was responsible for 58% of days with extreme water levels between 2000 and 2018 and has nearly tripled the number of such days since the 1970s. Ben Strauss, chief scientist at Climate Central and co-author of the Science Advances study, stated, "Essentially every coastal flood today has human fingerprints on it through climate change." The research underscores that even modest sea level rise can have severe impacts on coastal communities, threatening hundreds of millions of people living in low-lying areas and causing billions of dollars in damage.
Experts like retired USGS oceanographer Jeff Williams emphasize that planners must account for increased risks and invest in coastal protection, as current defenses in places like New Orleans may not suffice beyond a few decades. While global adoption of renewable energy is growing, scientists caution that the world is not on track for the best-case warming scenario, but also not for the worst.
Dangendorf added, "There is a silver lining because we have control about how much we emit, right? So we can stop that development, at least to some degree."