Rising seas threaten to flood thousands of miles of internet cables within the next decade.
Next time you scroll through social media or stream a video, think about this unsettling reality: the physical cables that carry your internet connection are sitting just inches above rising seawater along America’s coastlines. Most people assume the internet lives “in the cloud,” but it actually runs through thousands of miles of fiber optic cables buried underground, and many of those cables are about to get very, very wet.
Climate scientists and internet infrastructure experts have been studying what happens when these two forces collide, and their findings should make anyone who depends on reliable internet connection deeply concerned. Sea levels are rising faster than anticipated, and the bulk of America’s internet backbone was installed decades ago when nobody thought ocean water would reach inland fiber networks.
1. Over 4,000 miles of internet cables will be underwater by 2033.
University researchers mapped out exactly where America’s internet infrastructure sits compared to projected sea level rise, and the results paint a disturbing picture of digital disruption ahead. According to the University of Wisconsin-Madison study, more than 4,000 miles of buried fiber optic conduit will be submerged within the next decade, along with over 1,100 critical internet traffic hubs that currently route data across the country. These aren’t distant projections for the next century, but immediate threats happening in the next ten years.
The timeline shocked even the researchers who conducted the analysis, because most infrastructure planning assumes decades of lead time for climate adaptation. Instead, the internet backbone faces imminent flooding that will require emergency repairs, expensive rerouting, and potentially widespread service disruptions affecting millions of users who depend on coastal internet networks for work, communication, and daily life.
2. Major coastal cities face the most severe internet infrastructure threats.
New York, Miami, and Seattle emerged as the metropolitan areas facing the greatest risk of internet infrastructure flooding, though the effects won’t stop at city boundaries and will cascade across interconnected networks nationwide. These cities serve as critical hubs where transoceanic cables carrying international internet traffic connect to domestic fiber networks, making their vulnerability particularly dangerous for global communications, as reported by researchers at the University of Oregon. When these connection points flood, the ripple effects could disrupt internet service far from the original damage sites.
Miami already experiences regular flooding during high tides and storms, giving us a preview of how internet infrastructure performs under water stress. Seattle’s location near sea level puts its tech industry connections at risk, while New York’s role as a major internet hub means flooding there could affect financial markets, media networks, and business communications across the entire East Coast region.
3. Current internet cables weren’t designed to handle permanent underwater conditions.
The fiber optic cables currently buried along America’s coastlines can resist moisture and weather, but they’re fundamentally different from the waterproof submarine cables that carry data across ocean floors. As discovered by infrastructure researchers studying climate risks, these buried land cables will suffer damage when saltwater infiltrates their protective conduits, especially during freeze-thaw cycles that can crack or break the delicate glass fibers inside. The cables were installed 20-30 years ago when sea level rise wasn’t considered a serious threat to inland infrastructure.
Internet service providers face a costly choice between expensive upgrades to waterproof existing cables or complete rerouting around flood-prone areas. Some companies have started replacing vulnerable copper wiring with more flood-resistant fiber cables, but the scale of infrastructure at risk far exceeds current upgrade efforts, leaving vast networks exposed to saltwater damage that could cause widespread outages.
4. Hurricane Sandy previewed the internet chaos that flooding can cause.
When Superstorm Sandy hit New York in 2012, floodwaters knocked out internet service for millions of people by drowning underground cables and cutting power to critical network equipment. Verizon’s operations director called it a “catastrophic failure” that left entire neighborhoods digitally isolated for days while repair crews pumped water from flooded cable tunnels and replaced damaged hardware.
The storm offered a glimpse of how quickly internet infrastructure can collapse when water meets electricity and fiber optics. Manhattan’s financial district lost connectivity just as global markets needed to function, while residential areas faced communication blackouts that hampered emergency response and recovery efforts. These disruptions happened with temporary storm flooding, making permanent sea level rise an even more serious threat to digital connectivity.
5. Data centers and internet hubs sit directly in flood zones.
The massive data centers that store websites, process cloud computing, and route internet traffic are concentrated in coastal metropolitan areas where real estate was cheap and power was plentiful when they were first built. Now these facilities sit squarely in the path of rising seas, with hundreds of critical internet infrastructure points located at elevations that will be regularly flooded within decades.
Moving data centers inland requires rebuilding entire networks of connections, power systems, and cooling infrastructure that can cost billions of dollars per facility. Meanwhile, the internet keeps growing and demanding more data center capacity, creating pressure to expand in the same vulnerable coastal areas where existing infrastructure already faces flooding threats from climate change.
6. Saltwater contamination poses unique dangers to electronic equipment.
Unlike freshwater flooding that can be dried out and cleaned, saltwater creates corrosive conditions that permanently damage sensitive internet equipment and accelerate the deterioration of cables, servers, and network hardware. Salt deposits continue causing problems long after floodwaters recede, requiring complete replacement of affected equipment rather than simple repairs or cleaning.
Coastal internet infrastructure faces repeated exposure to salt spray, storm surge, and eventually permanent saltwater intrusion as sea levels rise. Each flooding event leaves behind salt residue that makes future failures more likely, creating a cascading cycle of equipment degradation that becomes more expensive and disruptive over time.
7. Internet service providers are scrambling to adapt their networks.
Major telecommunications companies acknowledge the climate threat to their infrastructure and have started implementing flood-resistant technologies, but the scale of adaptation needed far exceeds current efforts. Some providers are installing submarine-grade cables in vulnerable areas, elevating critical equipment, and building seawalls around important facilities.
However, most adaptation efforts focus on protecting the most critical infrastructure rather than comprehensive network hardening, leaving millions of customers dependent on vulnerable cables and equipment. The cost of fully climate-proofing America’s internet infrastructure would require coordinated investment from multiple companies and government agencies that hasn’t yet materialized at the necessary scale.
8. Global internet connectivity depends on vulnerable cable landing points.
The underwater cables that connect America’s internet to the rest of the world come ashore at specific landing points along the coast, most of which sit at elevations that will be regularly flooded as seas rise. These international connection points represent critical chokepoints for global internet traffic, and flooding them could isolate entire regions from international communications.
Rerouting international internet connections requires building new landing facilities inland and running new submarine cables to reach them, a process that takes years and costs hundreds of millions of dollars per connection. Meanwhile, existing landing points continue operating in increasingly flood-prone locations, creating vulnerabilities that could affect global internet connectivity far beyond American borders.
9. Economic impacts could reach billions in lost productivity and commerce.
Internet outages don’t just inconvenience users, they shut down entire sectors of the modern economy that depend on digital connectivity for basic operations. Previous studies of internet shutdowns show that even brief disruptions cost billions in lost economic activity, while extended outages could devastate financial markets, supply chains, and remote work arrangements that keep businesses functioning.
Climate-related internet failures could hit coastal metropolitan areas that generate enormous economic value through digital industries, financial services, and technology companies. A major internet disruption in New York alone could affect global financial markets, while outages in Seattle could impact major technology companies that provide internet services to millions of users worldwide.
10. The window for preventing internet infrastructure collapse is rapidly closing.
Unlike other climate adaptation challenges that unfold over decades, internet infrastructure flooding will begin happening within the next 10-15 years, giving engineers and policymakers an extremely narrow window to implement protective measures. Most climate-proofing projects require years of planning, permitting, and construction that must begin immediately to stay ahead of rising seas.
Waiting for flooding to begin before starting infrastructure adaptation means accepting widespread internet disruptions as seas continue rising throughout the rest of the century. The internet networks that modern society depends on for communication, commerce, and critical services need protection now, not after climate impacts start causing regular outages and permanent damage to coastal digital infrastructure.