Critical portions of America’s internet infrastructure, particularly in New York City, Miami, and Seattle, may be submerged and damaged by rising sea levels—possibly within the next 15 years, according to research presented Monday at a meeting of internet researchers.

The peer-reviewed study found that projected increases in coastal flooding over the coming decades—a trend linked with human-driven climate change—could have “a devastating impact on Internet communication infrastructure even in the short term.”

“The most immediate risk to the global internet is the fact that transoceanic fiber optic cables have landing sites that will be underwater in the coming years due to climate change-related sea water inundation,” said senior author Paul Barford, a University of Wisconsin-Madison professor of computer science, in an email to Motherboard.

Barford and his co-authors—University of Oregon computer scientist Ramakrishnan Durairajan and Carol Barford, director of UW-Madison's Center for Sustainability and the Global Environment—reached this conclusion by combining two important datasets for the first time.

By overlaying the Internet Atlas, a global map of the internet’s physical infrastructure, with the Sea Level Rise Inundation estimates generated by the National Oceanic and Atmospheric Administration (NOAA), the team was able to pinpoint where the most at-risk hardware is located.

“A gigantic amount of information is carried to and from the U.S. and the rest of the world every day,” Barford told me. “In the most extreme case, [rising sea levels] will cause global disruptions until the landing sites can be moved to higher ground. The good news is that there are a relatively limited number of these sites so addressing this risk has a limited scope and costs. After that, it's much more difficult to predict global impact—that is a subject of our ongoing work.”

One of the study’s most alarming findings is the short lead time before major communication lines will be affected. The team found that in the U.S. alone, 1,186 miles of long-haul fiber conduit and 2,429 miles of metro fiber conduit will be submerged by rising seas within the next 15 years.

While these cables are water-resistant, they are not fully waterproof. Exposure to saltwater could cause chronic internet outages, especially in U.S. infrastructure centers.

The study outlines a few suggestions for mitigating the immediate threat of rising sea levels to worldwide internet connectivity. Hardy backup conduits could be installed to reduce the risk of outages, and existing cables and landing points could be outfitted with protective layers. The team also suggests enacting policies to prioritize first-responder access to working internet lines in the event of emergencies.

But ultimately, these are stopgap fixes. Protecting internet infrastructure over the long term will require a more innovative approach that confronts the reality of climate change and its myriad implications.

“The bottom line is that most internet infrastructure that has been deployed did not have to consider climate change effects,” Barford said. “Going forward all deployment should consider climate change effects.”