The World Meteorological Organization says cold weather does not mean that global warming has abated. WMO says people should not confuse weather with climate.
People in Europe are shivering, while people in North Asia and parts of Australia are sweltering. Scientists say these weather extremes are to be expected and neither phenomenon can be used as a case for or against global warming.
Secretary-General of the World Meteorological Organization, Michel Jarraud, says people should not confuse local weather variability with climate change.
Just because people in Geneva and elsewhere in Europe are shivering does not mean global warming has stopped. He says the trend toward global warming is still there.
"I think we have to be careful not to interpret any single event as a proof of either warming or the fact that warming has stopped," he said. "When scientists look at the global warming, they take into account many, many old possible available evidence. So, we cannot explain any single phenomenon by one single cause."
Jarraud says last year was cooler than the year before, but 2008 still ranks as the 10th warmest year on record.
He says average global surface temperatures have climbed significantly since 1850, when historical weather statistics were first recorded.
"Global warming will mean that heat waves like the one we got in Western Europe in 2003 will become more frequent. But, it does not mean that the 2003 heat wave was produced by global warming ... Last year, we know that part of the relative cooling was due to the La Nina phenomena, which was moderate to strong in the first part of 2008. Then in the second part of 2008, it became closer to what we call neutral condition. Now, it is a little bit unclear what will happen this year," he said.
Jarraud says every year, somewhere in the world weather records will be broken. He says every year, exceptional weather events will take place somewhere in the world. He says people have to look at the global picture to assess whether climate change is taking place.
Scientists say human activity contributes to climate change, but they do not agree on the pace at which climate change may be unfolding.