So..

Produce more greenhouse gases to help the sun out a little?

@stephie, that would screw us in the 2050s... Like far worse...

So... Incentive to gtfo out of Canada for a (long) while?

And I said out twice. That's how dedicated I am to this idea.

Maybe we can get CO2 levels up for the mini ice age, then get those levels down afterwards again..

@Steephie: That is one o fthe stupidest ways of planning for this.

Once you release a single moleule of CO2 it can go almost anywhere in the atmosphere, recapturing it is very hard. Keeping it sored somewhere in the first place is much easier. If you consider the entropy change (as opposed to the energy, which doesn't need to change) it is a huge waste of entropy per molecule. And to get that entropy back you have to spend a huge amount of energy (generating entropy elsewhere, because you can never truely get entropy back... But there is a decent option of living off the emtropy increases of the sun, so we're in a pretty decent position here...)

I figured it was a horrible idea, just hoped to learn something from mentioning it.

CO2 is a crap greenhouse gas to do that with anyway. Methane would be far more effective, as you'd need far less. Then balance it out with Sulfites when we get too hot and we're sorted. Simple! ;)

I believe i recall a story of someone who swallowed a spider to catch a fly...

But aside from that, it is much easier to cool that planet by reflecting light than it is to heat the planet by, pretty much anything (short of a maybe massive fusion power plant... Oh wait, we have a sun already)

We can probably survive the impact on agriculture, especially if it is mostly mediated by current greenhouse gas levels. But still if this model is right (and i don't think we fully understand the earth's magnetic field, never mind the sun's*) then we're in for some interesting times - it would be cool to have decent data on agricultural production during the last minimum.

*The sun is a plasma, which means all the particles are charged, electrons and positive ion (H+, He+2, etc) which are all affected by magnetic fields; and also whenever the move they generate a magnetic field... Not simple at all.

The OP's line which differentiates between solar and climate predictions is a very revealing statement. It highlights in a nutshell much of what has been wrong about the global warming/climate change debate. Can someone please tell me why people insist on this greedy reductionism? How can we hope to predict climate without taking solar output into account?

How can they say with a straight face that ten years constitute a little ice age?

fulhamish: There is no debate on the ultimate effects of greenhouse gases on the global climate. Specific predictions about future climate variations (locally or globally) in a given year are helpful, but in no way affect the climate change thesis.

@fulhamish - touché.

You have a point. But you fail to see how something can be valuable to know and wrong.

With such complex systems as these, reductionism is the only way we can possibly gain an understanding.

So you can model climate with certain assumptions about solar output; and then repeat for a variety of other solar output assumptions. Then you can look at all the models, and after seeing the actual solar output you can tell if your model was right.

So it is still useful to be able to model them seperately.
And we can test our predictions. (Which is actually the more important part of predictions...)

Thank you for the reply Ora. To summarise your post would it be fair to say that if future solar output cannot be constrained we cannot accurately or precisely make climate predictions? We might get a handle on mechanism through retrospective fitting, but that is about as good as it gets.
What is actually needed, as ever, is hard observational/experimental data to feed into the computational models.

We can make models which we can determine are effective at prediction. These models do not include the possibility of aliens harvesting out atmosphere, or an asteroid impact which would throw dust into the atmosphere, blocking out sunlight, and killing all plant life and triggering a mass extinction event. It doesn't include the solar output, or the possibility of a neutron star passing through the solar system, or the possibility that God will trigger a rapture, as described in the book of revelations.

It does make predictions about the global climate. And every year we get another year worth of data to test the predictions against. And to adjust and improve the model. We have a tonne of archived data but the really high quality global stuff comes from climate monitoring satellites, which i believe were launched in the 90s.

Excellent follow up article: www.iflscience.com/environment/mini-ice-age-not-reason-ignore-global-warming

At ora, well in view of that list it sounds to me as though Principal Componant Analysis would really help. My guess is that the sun would be pretty high up on the list, certainly higher than some of those other ones you mention. Touche

Further what do the models now say about the temp record of the last ten years? How have they been 'refined'?

orathaic: Ha ha, that's a helpful follow-up article since it includes a couple quotes from the author of the study regarding this issue, but I would argue that it is by no means "excellent". A lot of further information or unknowns that could be helpful are left out.

fulhamish: Would you please look at my comment to you above? Do you not see how this study (which we don't have a link to, by the way) addresses an issue entirely independent to the known effects of greenhouse gases on the climate?

At JECE I of course agree with your physics on greenhouse gasses. I wonder though in such a complicated system as global climate how far such a simplistic approach takes us. For example, what are the consequences of the decline in the atmosphere temperature gradient or lapse rate?

http://www.washingtonpost.com/news/morning-mix/wp/2015/07/14/news-about-an-imminent-mini-ice-age-is-trending-but-its-not-true/

If you want a source that isn't I Fucking Love Science because I Fucking Love Science is the worst.

I wonder if the tree rings will go the right way this time or will we have another 'divergence'? You know the one that blotted out the mini ice age and the medieval warm period.

ghug: Thank you.

fulhamish: You're clearly getting all these random questions (on subjects you don't appear to know much about) from a list. Mind providing us with a link to your source?

fulhamish: For instance, this is all you need to know about tree rings and past climates:

The tree ring method depends on the fact that rainfall and temperature vary seasonally in the Southwest, so that tree growth rates also vary seasonally, as true at other sites in the temperate zones as well. Hence temperate zone trees lay down new wood in annual growth rings, unlike tropical rainforest trees whose growth is more nearly continuous. But the Southwest is better for tree ring studies than most other temperate zone sites, because the dry climate results in excellent preservation of wooden beams from trees felled over a thousand years ago.

Here's how tree ring dating, known to scientists as dendrochronology (from the Greek roots dendron = tree, and chronos = time), works. If you cut down a tree today, it's straightforward to count the rings inwards, starting from the tree's outside (corresponding to this year's growth ring), and thereby to state that the 177th ring from the outermost one towards the center was laid down in the year 2005 minus 177, or 1828. But it's less straightforward to attach a date to a particular ring in an ancient Anasazi wooden beam, because at first you don't know in what year the beam was cut. However, the widths of tree growth rings vary from year to year, depending on rain or drought conditions in each year. Hence the sequence of rings in a tree cross-section is like a message in the Morse code formerly used for sending telegraph messages; dot-dot-dash-dot-dash in the Morse code, wide-wide-narrow-wide-narrow in a tree ring sequence. Actually, the ring sequence is even more diagnostic and richer in information than the Morse code, because trees actually contain rings spanning many different widths, rather than the Morse code's choice between only a dot or a dash.

Tree ring specialists (known as dendrochronologists) proceed by noting the sequence of wider and narrower rings in a tree cut down in a known recent year, and also noting the sequence in beams from trees cut down at various unknown times in the past. They then match up and align ring sequences with the same diagnostic wide/narrow patterns from different beams. For instance, suppose that this year (2005) you cut down a tree that proves to be 400 years old (400 rings), and that has an especially distinctive sequence of five wide rings, two narrow rings, and six wide rings for the 13 years from 1643 back to 1631. If you find that same distinctive sequence starting seven years from the outermost ring in an old beam of unknown felling date with 332 rings, then you can conclude that the old beam came from a tree cut down in 1650 (seven years after 1643), and that the tree began to grow in the year 1318 (332 years before 1650). You then go on to align that beam, from the tree living between 1318 and 1650, with even older beams, and you similarly try to match up tree ring patterns and find a beam whose pattern shows that it comes from a tree that was cut down after 1318 but began growing before 1318, thereby extending your tree ring record farther back into the past. In that way, dendrochronologists have constructed tree ring records extending back for thousands of years in some parts of the world. Each such record is valid for a geographic area whose extent depends on local weather patterns, because weather and hence tree growth patterns vary with location. For instance, the basic tree ring chronology of the American Southwest applies (with some variation) to the area from northern Mexico to Wyoming.

A bonus of dendrochronology is that the width and substructure of each ring reflect the amount of rain and the season at which the rain fell during that particular year. Thus, tree ring studies also allow one to reconstruct past climate; e.g., a series of wide rings means a wet period, and a series of narrow rings means a drought. Tree rings thereby provide southwestern archaeologists with uniquely exact dating and uniquely detailed year-to-year environmental information.

– Collapse: How Societies Choose to Fall or Succeed, by Jared Diamond, pgs. 138–139

Your question makes no sense because tree rings from 1,000 years ago are only available for study in certain regions of the world, namely regions within the temperate zones which have had a relatively dry climate for centuries. The tree rings at these sites only tell the story of their local climates, not the global climate. Furthermore, tree rings relate ro annual precipitation and related factors, not necessarily temperature.

As for "the mini ice age and the medieval warm period", these were far less pronounced than the current climactic change we are facing. In fact, the evidence for them is inconsistent, suggesting that the phenomena may not have even had global scope.

@JECE, thank you for that. Are you saying that tree ring data is a measure of past climate? Are you further saying that this encompasses, for example, both temperature and rainfall? If so I agree with you on both counts.
I particularly like this remark: ''Furthermore, tree rings relate ro annual precipitation and related factors, not necessarily temperature.'' Do you hold to it?

On the mini ice age and the medieval warm period there is more than one point of view. I happen to think that you are wrong on yours. I could give you references if you like.

As to the tree ring divergence, with respect I do not think that you know what this means; similarly with lapse rate.
I used to think like you on this matter. However, when I read a few of those disgraceful climategate emails, it prompted me to ask questions. (Anthropocentric) Climate change might well be occurring, I cannot be sure or have any confidence in the numbers churned out by computational models. There is, in my view, rather a lot of questionable science being used to martial the case. I happen to think that the statistical treatment used to derive the hockey stick graph is a particularly prominent example.

www.sciencealert.com/there-s-more-to-that-mini-ice-age-story-and-here-s-why