(Express UK) The controversy over global warming hotted up last night after US scientists revealed that the Earth’s temperature declined over the past decade.
They said a surge in the use of coal-fired power stations in China may have helped cool the climate by pumping sulphur into the atmosphere.
But they also warned that the build-up of greenhouse gases such as carbon dioxide from fossil fuels like coal and oil means that respite will be short-lived – particularly as China is cleaning up its power stations and sulphur quickly drops out of the air.
The paper in the US Proceedings of the National Academy of Science comes amid continuing cracks in the consensus over climate change.
Global warming has long been blamed for the gradual melting of glaciers and scientists have warned over a rise in sea levels as a result.
Dr David Whitehouse of the Global Warming Policy Foundation said: “It is good news that the authors recognise that there has been no global temperature increase since 1998.
“Even after the standstill appears time and again in peer-reviewed scientific studies, many commentators still deny its reality.
“We live in the warmest decade since thermometer records began about 150 years ago, but it hasn’t got any warmer for at least a decade.”
He added: “There is as yet no convincing explanation for the global temperature standstill of the past decade.” The study by Robert Kaufmann, of Boston University, found that the Earth’s temperature declined between 1998 and 2008 even though the atmospheric concentration of carbon dioxide increased steadily. It said this was due to factors such as a quiet period of solar activity and cyclical shifts of ocean currents in the Pacific.
Most importantly, China doubled coal consumption between 2003 and 2007 – the same as the worldwide increase in coal in the previous 22 years – releasing sulphur into the atmosphere.
The researchers said this cooling effect may have counteracted warming expected from increased carbon dioxide concentrations.
But they warned: “The proposed explanation may portend a future period of rapid global warming as solar input rises and as China installs scrubbers that remove aerosols from coal-fired boilers.”
Piers Forster, professor of climate change at the University of Leeds, said the blip in warming would be “short-lived”. He added: “The masking of carbon dioxide-induced global warming by short-term sulphur emissions is well known.”