Ecosocialist Notebook

No, We are not headed for a little ice age

Recent headlines from supposedly serious newspapers and websites:

  • Solar Cycle Study Says Earth Will Experience ‘Mini Ice Age’ in 15 Years.
  • ‘Mini ice age’ coming in next fifteen years, new model of the Sun’s cycle shows
  • Scientists warn mini ice age could be 15 years away

Sounds scary, but don’t rush out and buy a parka. As Gregory Pijanowski explains on his excellent Pigeon Roost blog (below), this is just one more example of bad science journalism.
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Ian


Sigh … No, We are Not Headed for a Little Ice Age

A recent report by Professor Valentina Zharkova does not predict a mini-ice age as has been publicized by popular media.  In fact, nowhere in the RAS press release is that stated.  What Dr. Zharkova does predict is that the solar cycle will resemble the Maunder Minimum when there was little solar activity. During the same time, both Northern Europe and North America suffered cold weather referred to as the Little Ice Age from 1300 to 1850.

This prediction is the result of modelling solar activity with two solar dynamos rather than with one.  Both these dynamos have cycles of activity. When two cycles offset, they cancel each other out.  Zharkova’s model predicts the activity from the two solar dynamos will cancel each other out between 2030 and 2040.  This is referred to as destructive interference and an example can be seen below:

The Maunder Minimum was a period of little solar activity and as a result, very few sunspots were observed on the Sun’s surface:

Can the same Little Ice Age climate event be extrapolated if the Sun goes into a similar quite period?  The answer is no.  Atmospheric conditions on Earth today are much different than during the nascent Industrial Age.

Both carbon dioxide and methane are greenhouse gasses. That is, they trap heat at the Earth’s surface in the same manner a blanket traps bodyheat on your bed at night. Carbon dioxide levels have increased 60% and methane has increased by 300% in the atmosphere since 1750. And the trend is to keep increasing. For the sake of argument, if we were to cap carbon dioxide at today’s level of 400 parts per million, what would happen? Global temperatures would still rise 0.80 C (or 1.40 F) over the next few decades as the oceans continue to release heat trapped during the prior warming phase. How much would a return of the solar cycle to Maunder Minimum conditions reduce global temperatures? The drop would be 0.10 C globally. Not nearly enough to offset the effect of current greenhouse gas levels in the atmosphere, and not nearly enough to offset the most conservative expected increase of 1.00 C (or 1.80 F) over the next three decades.

This is very poor reporting of Valentina Zharkova’s work. A return to Maunder Minimum conditions refers to sunspot levels. There is no reason to expect a change to the Little Ice Age climate conditions. It’s unfortunate, if Zharkova’s predictions hold out, it represents a great discovery in solar physics and will allow more accurate modelling of solar activity and space weather. No small feat, as space weather does have potential damaging effects on electrical systems both in space and on Earth. And that is the true ramifications of this model.

Posted in Climate Change, Ecosoc Notebook, Science

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