The Sun has been unusually quiet lately, with the solar wind the slowest it's been in 50 years and the sunspot cycle reduced to nothing more than the occasional belch. But don't believe reports that this spells doom for humanity.
The Sun should be on an 11-year sunspot cycle, in which huge disturbances on the Sun's atmosphere become more and more pronounced until they reach a maximum of activity in 2013. But despite a few dramatic examples of sunspot activity, we're still way behind where we should be for this solar cycle, and it looks like the 2013 maximum is going to be one of the weakest on record. Moreover, this cycle may be so weak that it spawns an even more anemic cycle, meaning the predicted maximum in 2022 will be barely noticeable.
The magnetic fields that create these sunspots have been weakening for some time now, and the winds that should be found beneath the visible surface of the Sun have not been detected. All signs point to the Sun entering a period of mini-hibernation, perhaps even entering what's known as a grand minimum in which sunspots are not seen again for decades. The last known grand minimum was the Maunder Minimum between 1645 and 1715, a period of general cooling that is sometimes known as the Little Ice Age.
This has been picked up by a number of news outlets, with the more sensational conclusion being that we're headed for a mini ice age all our own. There are a number of problems with this idea, not the least of which is the fact that not all climate scientists are convinced that grand minima can actually cool the Earth - it's possible that the Little Ice Age was coincidental to the Maunder Minimum.
But even if a grand minimum can cool the Earth, its effects would be very minor relative to existing climatic pressures. Climate scientists recently simulated what would happen to the Earth if a grand minimum started now and lasted until 2100, a good thirty years longer than the Little Ice Age. They found that global temperatures would at most drop by about 0.3 degrees Celsius.
While even that might have some minor effects, it's nothing compared to the predicted temperature increase from global warming, as greenhouse gases are predicted to raise global temperatures anywhere from 2 to 4.5 degrees. So then, the effects of the grand minimum would need to be about ten times stronger than the simulations suggests they ever possibly could be for them to have any chance of overriding the effects of climate change. A Little Ice Age might sound rather nice under the current climate circumstances, but unfortunately the Sun won't be able to bail us out of this mess.