LONDON: Sunspots, rather than “greenhouse” gases from the burning of fossil fuels, may be responsible for the rise in global temperatures in the past 200 years, it was claimed on Wednesday.
Astronomers at Armagh Observatory in Northern Ireland have studied meteorological records going back to 1795, which point to a strong link between air temperatures on Earth and solar activity.
It is not the number of sunspots which affects the Earth’s climate, according to Dr Butler, but the length of the sunspot cycle. This averages about 11 years, but periods when the cycle becomes shorter correspond to greater solar activity and greater energy output.
Dr Butler pointed out that during the past 20 years, the solar cycle has been abnormally short (about 9.6 years) and the Earth’s weather abnormally warm. On the other hand, a period in the late 17th century known as “The Little Ice Age” when the Thames froze in winter, correspond ed with an abnormally long solar cycle, when sunspots virtually stopped for about 60 years.
