Sea levels much higher than previously thought due to "methodological blind spot," study finds

Rising sea levels caused by climate change may be significantly higher than previously thought, according to a new study, which says a "methodological blind spot" led researchers to underestimate existing coastal water levels. The revelation suggests that higher seas threaten tens of millions more people than scientists and government officials believed, with elevated risks for already vulnerable communities. In:

Rising sea levels caused by climate change may be significantly higher than previously thought, according to a new study, which says a "methodological blind spot" led researchers to underestimate existing coastal water levels. The revelation suggests that higher seas threaten tens of millions more people than scientists and government officials believed, with elevated risks for already vulnerable communities.

The new research, published in the journal Nature, reviewed hundreds of scientific studies and hazard assessments, calculating that about 90% of them underestimated baseline coastal water heights by an average of 1 foot. The study found it's a far more frequent problem in the Global South, the Pacific and Southeast Asia, and less so in Europe and along Atlantic coasts.

It's because of a mismatch between the way sea and land altitudes are measured, said study co-author Philip Minderhoud, a hydrogeology professor at Wageningen University & Research in the Netherlands. He attributed that to a "methodological blind spot" between the different ways those two things are measured. 

In the new study, he and his co-authors wrote that their aim was to eliminate the continued use of incorrect methodologies and what they called "widespread underestimations of coastal [sea level rise] and hazard impact assessments."

Each way of calculating sea and land altitudes measures those areas properly, he said. But where sea meets land, there are a lot of factors that often don't get accounted for when satellites and land-based models are used.