Reuters: The probability of a solar storm striking Earth in the next decade with enough force to do serious damage to electricity networks could be as high as 12 percent, according to solar scientists.

Is the risk as high as the article suggests?

  • I believe that a careful reading of Riley's paper does not support his conclusion of the 12% probability of a storm of Carrington magnitude in the next decade. Under various assumptions, estimates given in the paper range from 1.5% to 85%. The author himself rejects the 85% estimate as "not credible", but he uses exactly the same method on another part of the data to obtain his widely quoted 12% estimate. A detailed analysis of Riley's paper can be found at www.math.edu/~sp/analysis.pdf .
    – user22129
    Sep 14, 2014 at 23:49

1 Answer 1


This has gone viral.

Yes, the risk is high as the article suggests, this number was estimated (or calculated) by physicist Pete Riley, who receives fundings form NASA, NSF, and DoD. His recent publications can be found here.

Here is a direct quote from NASA, this was posted on July 25 2014:

In February 2014, physicist Pete Riley of Predictive Science Inc. published a paper in Space Weather entitled "On the probability of occurrence of extreme space weather events." In it, he analyzed records of solar storms going back 50+ years. By extrapolating the frequency of ordinary storms to the extreme, he calculated the odds that a Carrington-class storm would hit Earth in the next ten years.

The answer: 12%.

"Initially, I was quite surprised that the odds were so high, but the statistics appear to be correct," says Riley. "It is a sobering figure."

A severe storm could inflict damage estimated at between $1 and 2 trillion, 20 times the cost of Hurricane Katrina, with recovery time between 4 and 10 years. (1)

If you're interested in more information, look at this report by the National Academy of Sciences talking about the consequences of extreme solar storms.

(1) Severe space weather events: understanding societal and economic impacts, 2008.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .