Kiwi Scientists Cool On Theory Sunspots Are Causing Global Warming
Chris Mole - Associate Editor
July 28, 2004
NZ climate change experts are sceptical of a new study suggesting global warming is due to increasing radiation from the Sun, rather than man-made greenhouse gases.
A team of scientists from the Max Planck Institute for Solar System Research in Gottingen, Germany, has studied sunspot data going back several centuries and concludes the Sun is burning more brightly than at any time in the past 1000 years. The study shows a close link between sunspot activity and changes in the Earth’s temperature.
Dr Sami Solanki, who led the research, says: “The Sun has been at its strongest over the past 60 years and may now be affecting global temperatures.” Dr Solanki believes the impact of more intense sunshine on the ozone layer and cloud cover is causing global warming, although he doesn’t rule out man-made greenhouse gases as a contributing factor. If the new study is correct, it throws into question the world’s efforts to reduce greenhouse gases under the Kyoto Protocol, which will impose multi-million dollar costs on NZ businesses from 2008.
But NIWA’s top radiation scientist, Dr Richard McKenzie, says the study doesn’t contain enough new data to persuade him the world should abandon Kyoto. Dr McKenzie acknowledges “there does seem to be some link” between sunspot activity and global warming but scientists don’t yet understand how this relationship might work, so it’s unwise to put too much weight on it. He concedes a few decades ago scientists who espoused linkages between sunspots and climate change were considered to be in the “lunatic fringe” but this is no longer the case. “In fact, the last IPCC assessment attributes about one-third of the climate change in the last century to changes in solar output.”
However, the most active period of solar activity in recent years was about 1960, and global warming has increased markedly since then, which weakens the theory sunspots are the main cause of global warming.
Dr McKenzie is convinced the largest contributor to global warming is increased greenhouse gases. “The consensus among atmospheric research scientists is international agreements based on the Kyoto Convention will be needed to avoid serious climatic consequences from increased greenhouse gases.”
Officials from the NZ Climate Change Office won’t comment publicly on Dr Solanki’s research but privately they’ve expressed scepticism.
However, Dr Bill Burrows, a climatologist and member of the Royal Meteorological Society, welcomes the research. “This study is certainly significant. It shows that there is enough happening on the solar front to merit further research. Perhaps we are devoting too many resources to correcting human effects on the climate without being sure that we are the major contributor.”
Reinforcing Dr Solanki’s view is a recent finding Greenland ice samples contain the lowest recorded levels of Beryllium-10 for more than 1000 years. Beryllium-10 is a particle created by cosmic rays, which decreases in the Earth’s atmosphere as magnetic energy from the Sun increases.
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