Tuesday, July 24, 2018

The impact of rising sea level on Internet infrastructure

A recent study predicts that rising sea level might result in as much as 4,067 miles of fiber conduit being under water and 1,101 nodes (data centers, Internet exchanges, cable landing points, etc.) surrounded by water in U. S. coastal cities in 15 years.

Paul Barford, professor of computer science at the University of Wisconsin, and his colleagues have been compiling data on the physical Internet and making it available to the research community at the Internet Atlas Web portal since 2011. The portal includes an interactive visualization tool that can be used to create maps of Internet infrastructure in order to inform the public and guide network architects and policymakers.

Barford and his colleagues have combined their infrastructure data with sea level incursion projections from the National Oceanic and Atmospheric Administration (NOAA) in order to estimate expected damage to U. S. Internet infrastructure due to sea level rise and, as you see below, the NOAA data shows that sea-level has increased relatively rapidly off the U. S. coasts in recent years.


That is history, but NOAA also models future sea level rise and you can see predictions for specific locations using their Sea Level Rise Viewer (SLRV), a cool visualization tool. The SLRV predicts sea level rise through the year 2100 and computes estimates of sea level rise for five different scenarios at a selected location. For example, predictions for Miami, Florida for the year 2030 are: Intermediate Low scenario: 0.49ft, Intermediate: 0.75ft, Intermediate High: 0.98ft, High: 1.21ft and Extreme: 1.35ft. (The assumptions underlying the scenarios are spelled out here)

For this study, Barford and his colleagues used NOAA's Extreme scenario estimate of a global mean sea level rise of one foot per 15 years through 2100 and concluded that in the U. S. 4,067 miles of fiber conduit will be under water and 1,101 nodes (e.g., points of presence, Internet exchanges, cable landing points, etc.) will be surrounded by water in the next 15 years.

National outage due to hurricane
Sandy (source)
The study concluded that Miami, New York, and Seattle will be the hardest hit U. S. cities, but don't think you are home free if you live in Kansas -- the Internet is global and we are all affected by outages.

They also noted that since much Internet infrastructure is located near the coast in large cities, much of the future damage will occur fairly soon. Even if we assume the Intermediate Low scenario, Miami sea-level will have risen by a foot by 2015.

Los Angeles in 15 years
You can use the SLRV to check the situation in your local area using the scenario that best fits it. For example, this is what the coastal region of my city, Los Angeles, is projected to look like in 15 years using the Extreme scenario. The blue areas (on a green background) show expected sea level rise inundation and the dark green lines are fiber conduits.

Don't forget that Barford's analysis assumes the most aggressive of NOAA's scenarios and at the historical rate of sea-level rise we would predict less than 2 inches in the next 15 years.

On the other hand, Barford used the mean global extreme scenario estimate and North American cities have historically seen above average sea level increases.

Furthermore, he does not consider storm damage and this report shows that when hurricane Sandy hit the east coast in 2012, outages in New York and New Jersey led to a doubling of the national Internet outage rate. (You can read more on the impact of Hurricane Sandy on the Internet here).

Hurricane Katrina also damaged the Internet when it struck New Orleans in 2005. You can get a feeling for what it was like by listening to Doc Searle's interview of Sigmund Solares, then CEO of the DirectNIC data center. Solares describes the flooding and the extreme effort required to keep DirectNIC online.

(Note that the posts on Sandy and Katrina are at the Internet Archive since the original copies were no longer online).

Some people believe global warming is God's will -- it's good that He also endowed us with free will.