An Otago University environmental scientist believes the earth could be heading for a mini Ice Age during the next few decades, rather than global warming. Professor Geoff Kearsley notes there is an increasing body of science that says the sun may have a greater role in changing the climate than man-made greenhouse gases. Kearsley points out historical changes in the earth’s temperature appear to correlate with the frequency of sunspots. In periods of warmer temperatures, sunspots proliferated, but during the Little Ice Age, there were few or none for many decades, a phenomenon known as the Maunder Minimum.

Kearsley notes the last quarter of the 20th century saw a flurry of sunspot activity. The last cycle was at its peak in 1998, the earth’s warmest year for some time. Since then, there has been a static or even cooling trend as the sunspot cycle ran down. Kearsley notes 2007 saw “bitter weather” around the world and the mean global temperature dropped by an unprecedented amount. The Antarctic winter sea ice was at its largest extent since satellite observation began, and it snowed in Baghdad and Buenos Aires for the first time in living memory.

Kearsley says the latest sunspot cycle should have started up around the middle or end of 2006, but it didn’t. He adds, the longer trends indicate by 2020 we will be experiencing an unusually low-energy sun. Apparently, these are exactly the conditions which preceded the Maunder Minimum and ushered in the Little Ice Age. Kearsley concludes, “It may well be that human activity is indeed changing the climate, at least in part, but there is an increasing body of science that says the sun may have a greater role.” If this is the case, global warming is likely to stop, as it appears to have done since 1998, and if the current sunspot cycle fails to ignite, then cooling, possibly rapid and severe cooling, may eventuate.

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