Humanity would only have a 12-hour warning about the arrival of a “coronal mass ejection” that could damage the National Grid, pipelines and railway signals, according to a newly released document from the UK Cabinet Office.



In a report worthy of a Bruce Willis film, the Department for Business, Innovation and Skills (BIS) has set out the nature of the risk to the UK from “severe space weather”, which it says results from various types of solar activity.

The report, the Space Weather Preparedness Strategy, states: “Solar activity can produce x-rays, high-energy particles and coronal mass ejections of plasma. Where such activity is directed towards Earth there is the potential to cause wide-ranging impacts. These include power loss, aviation disruption, communication loss, and disturbance to (or loss of) satellite systems.”

According to the Cabinet Office, the most concerning element of severe space weather is the coronal mass ejection – explosive eruptions on the sun which cause large parts of the corona to blast away. As a result, it has developed a “reasonable worst case scenario” based on the Carrington event of 1859, which included the strongest recorded incidents of coronal mass ejection, as well as solar flare-related x-rays and a radiation storm.

Nasa’s Solar Dynamics Observatory caught this arching eruption on the side of the sun last month. Guardian

“Most coronal mass ejections are not emitted in the direction of Earth,” the report says. “Those that are typically take one to three days to reach us, and we can predict the arrival time to within about six hours. Predictions are currently less accurate due to degradation in the satellite capability available to forecasters.

“Generally speaking, the faster the ejection, the greater the potential impacts. The Carrington event, for example, travelled to Earth in as little as 18 hours. It is therefore likely that our reasonable worst case scenario would only allow us 12 hours from observation to impact.”



The Carrington event is often described as the perfect storm. The modern day effects of a similar event would include localised power outages; disruption of satellite operations, including to GPS and satellite communications; disruption to high-frequency communications; increased radiation to aircrew and passengers in flight, particularly over polar regions; and further disturbances to small-part electronic systems.

The UK’s approach to space weather preparedness is underpinned by three elements, according to the report: “Designing mitgation into infrastructure where possible, developing the ability to provide alerts and warnings of space weather and its potential impacts, and having in place plans to respond to severe events.”

Protocols have been developed between the Met Office and National Grid to warn of such an event and maximise the time for action to be taken – though there is no clear pattern on when an eruption happens.

While the sun has an approximately 11-year cycle of activity – the current cycle peaked in early 2014 – there is no evidence to suggest that the likelihood of severe space weather varies with the solar cycle.

“There are actions that the National Grid can implement to better protect the power grid. These need time and the 30-minute warning limits the range of mitigating actions that National Grid can take. The National Grid is reliant on the predictions of the Met Office,” the report says.

BIS, the Met Office, the UK Space Agency, the Natural Environment Research Council and a wide range of departments across government including the Department of Energy and Climate Change, the Department for Transport, and the Ministry of Defence all have a role to play in managing and preparing for the risk of severe space weather.

They have been helping the UK prepare for such an event by building on existing emergency planning. The risk of severe space weather was added for the first time to the National Risk Assessment project in 2011. The Met Office opened its 24/7 space weather forecasting centre in October 2014, and work has been done by National Grid to improve the resilience of its transmission network. The Cabinet Office also advises that the design of space weather-resistant technology be made a priority.

“Much more needs to be done to encourage potentially vulnerable sectors to adopt measures to mitigate the likely impacts,” the report states. “Communication with the public is an important component in preparing for and responding to an event … not all impacts may happen during every space weather event but pre-agreed messaging is important to allow rapid and effective communication from government, if and when they do happen.



“Preparation is needed to the national level, with the support of local capabilities to deal with the consequences. This all requires international co-ordination.”

Members of the public have been advised to plan for the effects of severe space weather in the same way as they would for other natural hazards such as a flood or storm.

• This article was amended on 29 July 2015. An earlier version misquoted the report as saying “Coronal mass ejections are not emitted in the direction of Earth”.