Rising sea levels endanger roads, homes, and now, research says—the internet. In a study published Monday, scientists examined the vulnerability of communication infrastructure to human-driven sea level rise. They found that in the next 15 years, more than 4,000 miles of data-carrying cables may be inundated by rising seas, including almost 25 percent of Seattle’s cables.
Behind every tweet, meme, and bank transaction is a vast network of fiber optic cables and other infrastructure that makes up the “physical internet.” These cables crisscross the country, connecting one place to another and carrying data between them almost instantaneously. Although the cables are designed to resist weather events, they are not meant to be permanently inundated by water.
Paul Barford and his colleagues have spent the past seven years combing public records. They were looking for any bit of information they could glean about the location of this infrastructure, often kept secret by the telecom companies that own it. Barford, the primary investigator of the study, is a professor of computer science at the University of Wisconsin-Madison. They call the resulting map the Internet Atlas.
When they laid their atlas over maps of projected sea level rise, they were surprised at what they found. Although many potential side effects of climate change are far down the road, this one was right around the corner.
“Climate change-related sea level rise is an immediate threat to internet communication infrastructure,” said Barford. “The great extent of the risks that we report in the paper are going to be realized in the next 15 years.”
Communication infrastructure naturally follows people. Like the country’s population, it’s heavily concentrated in coastal cities. Barford and his colleagues found that New York, Miami, and Seattle are the cities with the most internet infrastructure vulnerable to climate change. But it’s not just city-dwellers that should be concerned. The researchers note the potential for “waterfall effects,” where an outage in Seattle or New York would affect other parts of the country.
Because their networks are proprietary, telecom companies are the only ones who can say for sure how much risk sea level rise poses to their infrastructure. When asked to comment, CenturyLink said in a written statement that their networks were designed with redundancy to mitigate the effects of outages.
“We will continue to take all potential risks, such as the effects of climate change, into consideration in our ongoing planning and deployment of existing and new facilities,” their representative wrote.
For a more dystopian prediction, Barford points to the communications outages that followed Hurricane Katrina and Superstorm Sandy. Since sea levels are rising gradually, it’s unlikely that a blackout would occur here on a similar scale—but it’s good to keep in mind while planning for the future.
The worst-case scenario line of thinking is especially important because the study does not take these extreme events into account in its projections. The storm surges from such events would have an even greater impact on the infrastructure.
“I think this is exactly the kind of question we should be asking,” said Ian Miller, a coastal hazard specialist with the Washington Sea Grant. “It helps you understand where to put your effort, where to put your investment, and where to look for deficiencies.”
Miller and his colleagues are currently working on a new set of Washington state-specific sea level rise projections that they hope will be able to predict local effects more accurately. Although the sea level rise projection used in the study is on the high end of what scientists predict, other climate scientists agree that that’s the right approach to take.
“When you’re thinking about the risk of expensive assets or infrastructure that’s going to last a long time, you really want to think about these high or fast scenarios,” explained Amy Snover, the director of the climate impacts group at the University of Washington. “We have not yet comprehended how widespread the impacts of climate change are going to be, and this is a good example of that,” said Snover. “It’s one of lots of different coastally located infrastructure that are potentially vulnerable.”
Barford hopes this study will serve as a wakeup call.
“A tremendous amount of internet infrastructure will either be underwater or surrounded by water in coastal areas in the next 15 years,” said Barford. “There is a need for planning and to take steps to mitigate these risks sooner rather than later.”