The Sun is Turning Off!

Ok not really, but the solar dynamo looks like it's going to be quiet for the next few years. What this means is the current 11 year sunspot cycle, number 24, will likely peak at a lower set of sunspot numbers than the previous two cycles. Further, the decline in the Sun's magnetic field would seem to indicate that the next cycle, number 25 may be very small if not happening at all.

Further evidence also suggests that the sunspot cycle is slowing down. This all points to a period of solar inactivity that could stretch for decades. What this inactivity would mean is less solar energy reaching the Earth for the period of inactivity in theory resulting in cooler temperatures. This has happened before back in the mid to late 1600's when the Maunder Minimum occurred. This coincided with cooler temperatures world wide and much more severe winters in Europe, a period sometimes called the Little Ice Age. If the two events were causally conected, and the data we are getting from the Sun actually do indicates a reduction of solar activity is near, this would mean we should expect cooler temperatures for the next few decades.

If the Sun is indeed entering a period of quiescence, then what does it mean for us here on the Earth. With few exceptions, most of our energy comes either directly (solar, wind) or indirectly (fossil fuels) from the Sun. We should see a period of cooling. Here's where it gets tricky.

First the Earth's climate is a complex thing. Any cooling may not be evident for a decade or more due to the heat already built up in the system. Further if the current warming is either directly due to or being exacerbated by our carbon dioxide emissions, the cooling may not happen at all. In short it could mean the climate change debate will get even worse.

It will get worse because the deniers will say "See, we told you nothing was happening", when in fact a change in the input energy is masking the problem. The reality of the situation is the Sun will exit its quiescent state in about 50 or so years (if it acts as it did during the Maunder Minimum) and the energy will start to flow again. More energy will get trapped by the carbon dioxide in our atmosphere and things will get much, much warmer.

Of course, if there is sufficient greenhouse gas in the atmosphere now, it would mitigate the loss of energy and the planet just won't cool off. This would strengthen the argument for anthropogenic climate change as a sudden drop in energy didn't result in a drastic change in temperature downwards. Even worse for the deniers, many of whom say it's the Sun causing the warming, if temperatures don't drop significantly during the solar inactivity, then there would be undeniable proof of our industrial activity causing a warming.

So what does all this mean for the Earth? Well for the climate it will mean very little. A slight dip in the temperature is possible for a few decades. It's happened before, it will happen again. For human politics however it will extend a debate that needs to come to a conclusion sooner than later. Though it will buy us some time, we as a species will waste that time in needless bickering caused by vested interests in the fossil fuel industry and their spokespeople the Conservative and Republican parties.