Add solar storms to the disaster risk list. These high-energy bursts can interact with the earth's magnetic field, creating geomagnetic storms that could bring sudden, extended and widespread power and telecommunications outages over the next few years. The next peak in the 11-year cycle of solar disruptions arrives in 2012.
"We've been lucky, because the kinds of storms we've had in recent decades have been relatively low-intensity compared to those in the historical record," says Sten Odenwald, an astronomer at NASA's Goddard Space Flight Center. Odenwald points out that society's growing dependence on technology--especially electricity grids--would exacerbate the impact of a really big storm.