18 July 2018
Rising sea levels may result in thousands of miles of buried fibre optic cable in densely populated coastal regions of the United States from being flooded, says the University of Wisconsin-Madison and the University of Oregon.
The study portrays critical communications infrastructure that could be submerged by rising seas in as soon as 15 years.
An authority on the “physical internet” – the buried fibre optic cables, data centres, traffic exchanges and termination points that are the nerve centres, arteries and hubs of the vast global information network.
The study is the first assessment of risk of climate change to the Internet, and suggests that by the year 2033 more than 4,000 miles of buried fibre optic conduit will be underwater and more than 1,100 traffic hubs will be surrounded by water. The study only evaluated risk to infrastructure in the United States, but according to Professor Paul Barford of UW-Madison, the effects could ripple across the Internet, disrupting global communications.
Much of this infrastructure is buried and follows long-established rights of way, typically paralleling highways and coastlines, says Prof. Barford. “When it was built 20-25 years ago, no thought was given to climate change.”
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 fibre optic cables to sea water. Hints of the problems to come, says Prof. Barford, can be seen in the catastrophic storm surges and flooding that accompanied hurricanes Sandy and Katrina.
Buried fibre optic cables are designed to be water-resistant, but unlike the marine cables that ferry data from continent to continent under the ocean, they are not waterproof.
Risk to the physical Internet, says Prof. Barford, is coupled to the large population centres that exist on the coasts, which also tend to be the same places where the transoceanic marine cables that underpin global communication networks come ashore. “The landing points are all going to be underwater in a short period of time,” he notes.
Moreover, much of the data that transits the internet tends to converge on a small number of fibre optic strands that lead to large population centres like New York, one of the more vulnerable cities identified in the study.
The impact of mitigation such as sea walls, according to the study, are difficult to predict. “The first instinct will be to harden the infrastructure,” Prof. Barford says. “But keeping 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.”
The findings of the study, argues Prof. Barford, serve notice to industry and Government. “This is a wake-up call. We need to be thinking about how to address this issue.”