Global warming slows down ... thanks to more pollution in our atmosphere - Vancouver Sun

Global warming has slowed in the past decade, figures from Britain's meteorological office suggest.

The world is pumping out so much pollution it is reflecting more of the sun's rays and thus constraining heating by the sun.

The latest figures from more than 20 scientific institutions around the world show that temperatures are higher than ever.

However, the gradual rise in temperatures over the past 30 years is slowing slightly.

Global warming since the 1970s has been 0.16 C per decade but the rise in the past decade was just 0.05 C.

Skeptics suggest this is evidence that man-made global warming is a myth.

The British report that the reduced rate of warming can be easily explained by a number of factors.

Indeed, the true rate of warming caused by man-made greenhouse gases could be greater than ever.

One of the major factors is pollution over Asia, where the growth in coal-fired power stations mean gases such as sulphur are being pumped into the air. This reflects sunlight, thus cooling the land surface temperature.

Vicky Pope, the head of Climate Change Advice, said pollution may be having a cooling effect.

"A possible increase in aerosol emissions from Asia in the past decade may have contributed substantially to the recent slowdown," she said.

Pope said the global temperature was still rising and 2010 was set to be the second warmest year on record.

Other groups, including the U.S. space agency NASA, think 2010 will be the hottest year on record at about 0.5 C above the 1961-1990 average of 14 C.

Pope said the world should not be lulled into a false sense of security because the warming trend had slowed down.

In Britain especially, people are less worried about global warming because of a run of cold winters, including snow this weekend. But this is a short-term trend.

Pope said that in the long term the world, including Britain, was getting warmer. "If you look at the long-term trends we are in fact experiencing fewer freezing winters and more heat waves," she said.

Pope also said warming in the Arctic was likely to be greater than the rest of the world but its statistics were not included because of the lack of weather stations at the poles.

Also more accurate readings of sea surface temperature, using buoys rather than ships, suggest that temperatures for the past decade are about 0.03 C higher than estimated.

More than 190 countries are meeting in Cancun, Mexico, for climate change talks later this month to discuss the best way to bring down emissions so that the rise in global temperatures remains below 2 C.

At the moment the global temperature rise is 0.8 C above pre-industrial levels.