A U.N. plan to upgrade "space weather" forecasts can help the world cope with solar storms that might wreak up to $2 trillion in damage if the sun repeated a giant flare of 1859, experts said.

The sun is entering a more active phase due to peak in 2013 on a roughly 11-year sunspot cycle, the World Meteorological Organization (WMO) said. Power supplies, air traffic control, communications and satellites can all be disrupted by storms.

"We are increasingly being impacted by space weather," Barbara Ryan, director of the space weather program at the Geneva-based WMO, told Reuters. She said there was a need to coordinate forecasts and upgrade warnings of looming storms.

"No country has enough resources alone ... we need observations from all over the globe," she said. "A common alerting protocol (is) an issue we will be looking at over the next couple of years" to help limit impacts.

Geomagnetic storms on the sun take between half a day and 5 days to reach the earth after they erupt. China alone has 20 monitoring stations on land tracking the upper atmosphere, the higher ionosphere and the sun.

The 189-member WMO agreed at a May 16-June 3 congress to boost international coordination of space weather, working with the International Space Environment Service and the International Civil Aviation Organization.

Among goals are to "improve space weather warnings to major application areas including aviation," it said. The WMO would encourage sharing of data and help coordinate research.

Early warnings can allow countries to reroute flights to avoid polar routes, turn off unnecessary electric equipment or switch frequencies of some transmissions. In the longer term, research can bring improved designs to shield vulnerable equipment.

A solar superstorm on September 1, 1859 -- named after British astronomer Richard Carrington who observed it -- set off fires in telegraph offices and produced an aurora so bright that people could read newspapers at night by the glow, NASA said.


The high-tech economy is now far more vulnerable. A report by the U.S. National Academy of Sciences has estimated a similar storm today could cause $1 to $2 trillion in damage and require four to 10 years for recovery, NASA said.

"WMO has an opportunity to coordinate action to address a growing environmental vulnerability," Jack Hayes of the U.S. weather service told a space weather event during the WMO congress in Geneva.

A 2003 storm caused re-routing of flights over polar routes most vulnerable to disturbances, led operators to reduce output from U.S. nuclear power plants and damaged transformers in South Africa, he said.

Ryan said that better forecasts could help the world improve protection for vulnerable personnel, especially astronauts, and equipment such as power stations and communications networks.

Space weather forecasts could get more widely known -- with scales like those used to measure earthquakes or hurricanes. "We'd like to bring the same kind of structure to space weather," she said.

The U.S. National Oceanic and Atmospheric Administration uses scales of one to five, where five is the most severe, for geomagnetic storms, solar radiation storms and radio blackouts.