The Sun on Oct. 2010, left. On the right, an Oct. 2012 image shows a much more active Sun, which is expected to reach the "solar maximum" later next year. Image: NASA's Solar Dynamics Observatory.
The idea that solar storms can deliver serious disruption at intervals of once every hundred years is based on limited historical data. "That's as good as an estimate as anyone can give," said W. Jeffrey Hughes, director of Boston University's Center for Integrated Space Weather Modeling and a professor of astronomy.
The 1859 solar storm is now called the Carrington Event, possibly the strongest on record. But there was another, the "great storm" in May 16, 1921, which disrupted communications and power. More recently, a solar storm in 1989 was responsible for a power outage in Canada affecting 6 million. Solar storms have hurt satellites, and disrupted an FAA GPS system.
Predicting the impact of a solar maximum is difficult. Hughes likens it to hurricane season: You don't know either the severity or the types of storms that will arrive, or types of damage they may cause.
But Hughes said a solar storm has the potential of knocking out the power grid by putting DC current into large, purpose built transformers operating on AC current. These transformers cost several hundred million dollars, "and the come from places like Brazil these days." If one goes out, it may take six months for a replacement, he said.
Something else that could affect systems on a vast scale is cyberwar. It also made the government black swan list. Government officials have always been outspoken about the risks, in part, to encourage the private sector to do more. But lately, these alarms have been shrieking.
In October, U.S. Defense Secretary Leon Panetta warned that a cyberattack could "virtually paralyze the nation."
One company that studies cyber risks, Verizon, said this week that it doesn't believe that there will be all-out cyberwar next year, although it is possible. But Verizon is forecasting -- with 90% probability -- that the No. 1 security threat will be authentication-related. It says that nine of 10 intrusions will involve compromised identities.
Trend Micro, in its predictions for next year, says politically motivated attacks will become more destructive in 2013. Another concern major concern is climate change.
"Dramatic and unforeseen changes already are occurring at a faster rate than expected," reported the U.S. Global Trends report. "Most scientists are not confident of being able to predict such events."