Rising sea levels are going to mess with the internet sooner than you think

Fibre-optic cables have been laid around Thames and several other Thames-Coromandel coastal towns in the last couple of years as part of a nationwide rollout.  Much of this cabling has been laid underground on land less than half a metre above sea level rise – for example, the coastal suburbs of Moanataiari, Tararu, Grahamstown and Shortland – even the CBD.  Will this massively expensive technology have to be replaced above ground in just a few years sea levels and salty groundwater levels rise?

A new study called “Lights Out: Climate Change Risk to Internet Infrastructure” has thrown up the huge risks that rising sea levels have for this complex infrastructure.  Rather than having 50 years to plan to relocate these cables, many of these low-lying areas will be inundated by rising seas within the next 15 years according to the study.

The total cost of the rollout for New Zealand will be close to $2 billion.  How much of this spending will be wasted because the previous government and Spark/Chorus charged ahead with installations regardless of the risk from sea level rise?

While pipes carrying streams of information along the ocean floor can withstand the stresses of the sea, these are very different than the cables buried on land.

The optical strands themselves can be impacted if the inundation is bad enough, the study said, citing risks like:

• Signal attenuation due to water molecules embedding in fibre micro-cracks;
• Corrosion damage to connectors;
• Signal loss in optical-electrical-optical connections;

The researchers estimated that in total more than 4,000 miles of buried fibre optic cable in the US alone will be submerged by 2033.

Local Government New Zealand is undertaking a review of infrastructure at risk from rising seas.  It will be fascinating to see whether the fibre network is included in this review, and if so, what the extent of the risk is estimated to be.