The Sun is constantly bombarding Earth with electromagnetic particles in the form of solar wind, which mostly dance their way harmlessly to the poles of the planet leaving behind shimmering auroras. Occasionally however, every one hundred years or so, the wind transforms into a full solar storm, which could have significant consequences for modern life.

New research presented at SIGCOMM 2021 – a leading annual communication technology conference – warns that, if severe enough, the next solar storm could plunge the world into an “internet apocalypse” that keeps large swathes of society offline for weeks or even months at a time. 

Sangeetha Abdu Jyothi, an assistant professor at the University of California and author of the research paper told WIRED: “What really got me thinking about this is that with the pandemic we saw how unprepared the world was. There was no protocol to deal with it effectively, and it’s the same with internet resilience... our infrastructure is not prepared for a large-scale solar event.”

Abdu Jyothi’s paper states that these violent solar events, also known as coronal mass ejections, have a 1.6 to 12 per cent chance per decade of impacting Earth directly. The last major such event to hit the planet was recorded in 1859, named the Carrington Event, and was so severe that in the US telegraph wires burst into flames, fire poured from circuits, and auroras were visible as far south as equatorial Colombia.

The world is much more reliant on communications technology today than it was then, with Abdu Jyothi predicting that just one day without the internet could cost the US $7 billion (£5.08 billion). “What if the network remains non-functional for days or even months?” Abdu Jyothi adds in her paper.

Local internet connections, however are not at risk as fibre-optic cabling is not directly affected by geomagnetic events. It is the long undersea cables connecting continents that are vulnerable to disruption, and if enough of them fail, entire continents face being cut off from one another. The US and the UK are among the nations most at risk here, due to their high latitudes, according to the paper. 

While it is not easy to predict how long it would take to repair underwater infrastructure, Abdu Jyothi adds that the Earth will have roughly a 13 hour warning to prepare for the arrival of a severe solar storm. Hopefully we can be ready when the time comes.