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The possibility of imminent solar dormancy was raised by reports from the ongoing American Astronomical Society meeting of fading sunspots and dips in the sun’s magnetic patterns. Those are considered portents of solar inactivity, suggesting that the next solar minimum — a natural downturn in activity — would be especially pronounced, perhaps lasting for decades.

When that last happened, between the mid-17th and early 18th centuries, northern Europe experienced a period of unusually cold weather. Known as the Maunder Minimum, or more conversationally as the Little Ice Age, it’s a period historicized by accounts of ice skating on the Thames and seasonal inns built on Baltic Sea ice.

In fact, the meaning of the latest sunspot reports is still being debated, as Andrew Revkin at Dot Earth has chronicled. But even if they really do portend a decades-long solar lull, studies already point to a minimal effect on climate

Most Little Ice Age cooling appears to have been the result of coincidentally high volcanic activity that cloaked Earth in sunlight-blocking soot. As for the sun, a study published in 2001 in Science found that reduced solar activity produced a cooling effect of about 0.5 degrees Fahrenheit. In other estimates, the cooling is even more insignificant.

More recently, in a 2010 Geophysical Research Letters study, Georg Fuelner and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research asked the question directly: What would happen if Earth experienced another 70-year-long solar minimum?

The answer can be seen in the image at the top of this post, which estimates the temperature difference between a solar minimum future under “middle-of-the-road” climate scenarios and the Maunder Minimum. In a nutshell: It’s going to be much, much hotter in the future, solar minimum or not.