On 10 February the Solar Orbiter, a European space probe, began its long journey to study the Sun close up. The aim of the mission is to peer at the Sun’s poles and assess the solar winds and solar flares that emanate from the surface and appear in the Sun’s outer atmosphere or corona.

Solar flares – sudden spikes in the sun’s brightness, sometimes referred to as coronal mass ejections (CMEs) – increase radiation levels around the Earth which can interfere with satellites’ electronics, disrupt radio communications and cause damaging surges in power grids.

In 1859, a massive CME damaged telegraph systems across America and Europe. Observed by British astronomer Richard Carrington on 1-2 September that year, the incident became known as the Carrington Event. Less severe storms occurred in 1921 and 1960 but widespread radio disruption was still reported. In March 1989 a geomagnetic storm knocked out power across large sections of Quebec causing nine-hour blackouts. In July 2012 a ‘Carrington-class’ CME narrowly missed the Earth by nine days.

According to a 2013 study conducted by the Lloyd's of London insurance company and Atmospheric and Environmental Research, the duration of these effects could last longer than a year and costs could rise to US$2.5 trillion. While the probability of a CME is rated as 12% by some, other research puts it at less than 2%. Certainly, the UK’s National Risk Register (2017) puts the potential likelihood of a space-weather event occurring in the next five years as four on a maximum scale of five, with the impact severity as three out of five – alongside emerging infectious disease and heatwaves.

At a seminar in 2018 on ‘Infrastructure and Societal Resilience to Black Sky Hazards’, Lord Harris of Haringey made four key points: first, cities will be paralyzed without electricity; second, no single sector can function without the partner sectors on which each depends; third, a prolonged, widespread power outage would cause cascading failures of other systems; and fourth, it is essential to plan for the mitigation of low-probability but devastatingly high-consequence events.

See Lord Harris’s article ‘Are we ready if the lights go out? on this website here.