It's a hallmark of modern apocalypse movies: Someone tries their cellphone, and when they (gasp!) have no reception, they try the internet. That's when the real horror hits, because the internet isn't working, and not even memes can save them now. All joking aside, though, climate change does pose a real threat to the internet, according to a new study. The report suggests that underground fiber optic cables that provide internet to heavily populated areas along the West and East Coasts of the U.S. may be underwater within the next 15 years.

Per a report for the study published on EurekAlert, "thousands of miles" of fiber optic cables are in danger of being plunged into the rising sea, meaning millions of people could lose access to the internet we've all come to depend on. According to The Royal Society, a fellowship of scientists and scientific institutions, our global sea level is currently rising at about 0.12 inches per year — eight inches since 1901.

While that may sound like an incremental amount, adding that amount year over year piles up, and it's piling up quicker than we thought, Paul Barford, a University of Wisconsin-Madison professor and a lead author on the study, said in the statement posted on EurekAlert. "Most of the damage that's going to be done in the next 100 years will be done sooner than later," Barford explained. "That surprised us. The expectation was that we'd have 50 years to plan for it. We don't have 50 years."

In fact, we have less than 20, the study, which comes out of the University of Wisconsin-Madison and the University of Oregon, estimated, based on an "assessment of risk of climate change to the internet," per the statement. According to the statement, the assessment is the first of its kind, and it may be extremely timely, considering Barford and fellow researchers Ramakrishnan Durairajan and Carol Barford discovered that more than 4,000 miles of fiber optic cables will be underwater by 2033.

"Many of the conduits at risk are already close to sea level and only a slight rise in ocean levels due to melting polar ice and thermal expansion as climate warms will be needed to expose buried fiber optic cables to sea water," researchers said in the study statement.

Barford and fellow researchers found those who are most at risk of losing their access to internet are residents of New York, Miami, and Seattle, "but the effects would not be confined to those areas and would ripple across the internet," Barford said in the study statement. That ripple effect could bring a sort of digital apocalypse of its own, going so far as to affect global communications abilities, he added.

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What's more, researchers only looked at the U.S. for this study, but the findings could be extrapolated to other countries that utilize fiber optic cables — or other types of infrastructure cabling — located in areas that aren't high enough above sea level. Barford explained that most of the cabling he and fellow researchers investigated in the U.S. was put in place between 20 and 25 years ago, when "no thought was given to climate change." On top of the rising sea level, there's the danger of our increasingly worsening natural disasters, which Barford said in the study statement are "[h]ints of the problems to come."

As for what we can do about it, it may seem like a large-scale refurbishing of physical internet infrastructure is in order, but Barford said that won't do us much good. "[K]eeping the sea at bay is hard. We can probably buy a little time, but in the long run it's just not going to be effective," he said in the study statement.

Ultimately, it's climate change that needs to be addressed if we want to protect the fiber optic cables at risk — and the rest of the Earth, of course. For policymakers and corporations whose production processes contribute to climate change, "This is a wake-up call," Barford said.