Sunspots And Climate Change Deniers

For over a week now Honolulu, Hawai'i, has been playing host to the 29th General Assmebly of the International Astronomical Union. Sadly this is not a precursor to Starfleet but it is still rather exciting nonetheless. The Union represents over ten thousand astronomers and the triennial meeting is always a wellspring of cutting edge space science.

On August 7th they released information about the longest continuous experiment in existence which dates back to observations taken by Galileo Galilei. It was all to do with sunspots. You see, from 1645 to 1715 there was what is sometimes referred to as a mini ice age; whist this is a factually poor description of what happened it is certainly true that winters were harsher during this period. This coincided with a prolonged trough in solar activity known as the Maunder Minimum and so it was that we have assumed for several centuries that the former was caused by the latter. Solar activity is measured by counting the number of sunspots visible on the surface of the sun at any given time: the more spots the more activity. More recent data, however, has started to contradict this hypothesis and so the whole model has come under increasing scrutiny.

This is significant because if solar activity has been steadily increasing for the past 300 years then it could go some way to explaining the warming of the planet that is such a pressing concern today. It would also mean that if the warming isn't anthropogenic (manmade) in origin then our various warnings about carbon emissions and heavy industry are incorrect. I know I personally have met people, let's call them climate change deniers, who say that us puny humans are incapable of affecting a whole planet in this way, and, that solar activity explains everything so it's fine to have a coal powered car built from amazonian mahogany. Well, the new data, which reconciles a long running discrepancy in the two ways we can count sunspots, shows that solar activity does not in fact correlate with the steady increase in global temperature that we have been observing since the beginning of the Industrial Revolution. To quote them:

'[these results] make it difficult to explain the observed changes in the climate that started in the 18th century and extended through the industrial revolution to the 20th century as being significantly influenced by natural solar trends.'

Notice that there is wriggle room in that statement, but that is because it was issued by scientists who understand that new data can always change your theory. As it goes, that is actually quite a strong statement and would be a blow to the climate change deniers if their position was in any way based on reality. So there you have it, one more line of evidence to support anthropogenic global warming, one less place for the climate change deniers to hide. Will it change any of their minds? Not a chance.

Hand drawn by Galileo himself this is one of a series of drawings that show the
progress of sunspots across the surface of the sun with time.