“The public is recommended to stay informed through national UV forecasts,” UN body the World Meteorological Organization (WMO) said in a statement on Tuesday.
The depletion of the ozone layer – which protects against skin cancer – has reached unprecedented levels due to record-low winter temperatures in the upper atmosphere, according to the WMO, which compiles global ozone data.
The problem is particularly acute for Sweden as winds have forced the hole in the ozone layer over Scandinavia and sun-thirsty Swedes are being warned against flagrant exposure to the sun’s rays.
By the end of March, some 40 percent of the ozone layer had disappeared, beating a previous record of 30 percent, despite an international agreement aimed at cutting the production and consumption of ozone destroying chemicals.
The Montreal Protocol was signed in 1989, and last revised in 1999. The treaty was designed to protect the ozone layer by phasing out the production of numerous chemicals believed to be responsible for depletion. If adhered to it is expected to enable the ozone layer to recover by 2050.
Ozone is destroyed by reactions with these industrial chemicals, which, while they are restricted by the protocol, can cause damage continuing for several decades.
The WMO reported that while the 2010/11 ozone destruction is unprecedented, it is not unexpected with significant Arctic ozone loss foreseen as a possible scenario by scientists in the event of a a cold and stable stratospheric winter.
“The degree of ozone loss experienced in any particular winter depends on the meteorological conditions. The 2011 ozone loss shows that we have to remain vigilant and keep a close eye on the situation in the Arctic in the coming years,” WMO Secretary-General Michel Jarraud said.