By Ericcson

Craig Donovan, a researcher at the EMF Safety and Sustainability division of Ericsson Research, has recently completed a thesis on the environmental impact of submarine fiber-optic communication cables. The study reveals that they leave only a minor carbon footprint in relation to the data capacity of a modern system.

Donovan says that submarine cables are the backbone of transcontinental communication. Using fewer resources to install per unit length than an underground terrestrial cable, the cables transmit data in a highly efficient manner and have a relatively small environmental impact per unit of data sent.

In his thesis Donovan demonstrates that the use of submarine cables, which carry over 97 percent of our transcontinental data and voice communications, will be a key component in hitting Ericsson’s target of 50 billion connections. “Without them, communication on the scale we have today would not be possible and the target could not be realized,” he says.

His study shows that a fiber-optic submarine cable, with an average commercial lifespan of 13 years, releases just 7g of carbon dioxide equivalents for every gigabit of data sent along 10,000km.

He points out that comparing the amount of data sent during a telepresence meeting between Stockholm and New York to the air travel required for a face-to-face meeting results in a difference of almost 2 tonnes of carbon dioxide per person for a two-day meeting. That is the equivalent of driving the average passenger car almost 12,000 km.

Donovan says that the emissions released could be further reduced by using more efficient ships, cleaner fuels and electricity from renewable sources. He also suggests that increasing data traffic by boosting the capacity of the submarine cable would reduce the impact per data unit. “The data capacity of modern submarine cable systems can be increased by upgrading only the terminal equipment while the existing cable can remain in use,” he says. This means more data and less environmental impact per gigabit.

The commercialization of 40Gbps data transmission is on the horizon, and this will gradually replace the current 10Gbps transmission equipment. This will further improve environmental performance and increase the number of connections possible per transmission. “Also extending the lifetime of the cable beyond 13 years would reduce its potential environmental impact as more data can be sent during the cable's lifetime,” Donovan says.

“Greater capacity will therefore help us reach our 50 billion connections target and allow it to be done in a more environmentally responsible manner.”