Your data may be stored in the cloud, but it often travels through cables that are right here on Earth. And as sea levels rise, some of those cables could end up underwater.

“The land-based infrastructure is designed often to be water-resistant but not to be waterproof,” says Carol Barford, a research scientist at the University of Wisconsin-Madison.

She was part of a team that analyzed how sea-level rise could affect internet infrastructure on coastlines.

They found that with just one foot of global sea-level rise – which is possible within 20 years – more than 4,000 miles of fiber optic cable would be under water at least half of the time.

Barford says that long-term exposure to water, humidity, and ice can reduce signal strength, corrode connectors, and even break the glass fibers.

“There’s actually a variety of physical risks,” she says. “The stuff just isn’t designed to be underwater.”

She says in some places, upgrading hardware or relocating cables may help address the problem. So she says cities and internet service providers need to start making plans now about how they will protect the internet as sea levels rise.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.