Slashdot Mirror
Mini Ice Age: Nothing To Worry About
Geoffrey.landis writes: Last week a news story suggested that a new model of sunspot activity predicted a dramatic drop in solar activity coming up, possibly resulting in coming a mini-ice age. Take that prediction with a bit of skepticism, though-- later news analysis suggests that the story may be more media hype than science. Valentina Zharkova, the scientist whose research is being quoted, made no mention of a "mini Ice age"-- her work was only on modelling the solar dynamo. And, in any case, the solar minimum predicted was estimated to last only three solar cycles-- far less than the 17th century Maunder Minimum.
Phil Plait, known for his "bad astronomy" column, does a more detailed analysis of the claims, pointing out that the effect, if it even exists at all, is weak-- and the much discussed "Little Ice Age" is currently believed to most likely have been triggered by volcanic action, not sunspots. And, in any case, any predicted cooling is small compared to already-present global warming. So, probably no need to stock up on firewood, dried food, and ammunition quite yet-- the mini ice age isn't likely to be coming quite yet.
Phil Plait, known for his "bad astronomy" column, does a more detailed analysis of the claims, pointing out that the effect, if it even exists at all, is weak-- and the much discussed "Little Ice Age" is currently believed to most likely have been triggered by volcanic action, not sunspots. And, in any case, any predicted cooling is small compared to already-present global warming. So, probably no need to stock up on firewood, dried food, and ammunition quite yet-- the mini ice age isn't likely to be coming quite yet.
If it's been 400 years since the Maunder Minimum, and assuming we peak on temperature right now, wouldn't that mean the new minimum is still a problem for our [great-]+grandchildren?
What climate scientists are saying is not that the Sun has no effect but that there is not enough variability in the Sun to account for the changes we've seen. The incoming energy from the Sun's radiation is of course critical to the Earth's climate. The variability of the Sun from a Maunder Minimum condition to the maximum output we've see is on the order of 0.2% which is less than the forcing of the added CO2 in the atmosphere.
And based on what astronomy knows about G-type main sequence stars there's no reason to expect a drastic increase in the variability of the Sun.
It's called the Maunder Minimum for a reason. There is definitely a correlation with sun activity... and my guess is that it's better than the correlation with volcanism. I don't know that for sure, but that's my best recollection.
It is easier to believe the documented condition of the sun going quiet for a few hundred years was the major factor behind the cooling than it is to believe one or more volcanoes were going off constantly for a few hundred years creating an ash blanket over the Earth for the whole period and caused it.
What they say is that the short-term solar cycles have no effect on the climate.
"Little Substantial Effect" of the ups and downs of the individual cycles themselves and their usual cycle-to-cycle variations (rather than the exceptional cases of multi-cycle sunspot minimums), if I'm not mistaken.
If the Maunder Minimum (about five cycles long) was responsible, or even a substantial contributer to, the Little Ice Age, the effect of that variation Was substantial. It's the largest of three sunspot minima events that have been observed since sunspots were first noted as a significant phenomenon of scientific interest, and each of the minima was accompanied by a substantial worldwide cold snap. So let's not claim the scientists are dismissing it out-of-hand.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way