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It's the sun
Climate's changed before
There is no consensus
It's cooling
Models are unreliable
Surface temp is unreliable
Ice age predicted in the 70s
We're heading into an ice age
It hasn't warmed since 1998
Antarctica is cooling/gaining ice
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Latest Posts

We're heading into a new Little Ice Age

The skeptic argument...

Next week, next month, next year, it's not a question of if, only when. One day you'll wake up -- or you won't wake up, rather -- buried beneath nine stories of snow. It's all part of a dependable, predictable cycle, a natural cycle that returns like clockwork every 11,500 years... And since the last ice age ended almost exactly 11,500 years ago... (source: Ice Age Now)

What the science says...

Russian scientist Habibullo Abdussamatov predicts that around 2040, the sun will cool down to Maunder Minimum levels (Abdussamatov 2005). This was a period in the 17th Century with almost no sunspots for 70 years, coinciding with the Little Ice Age. Could a cooling sun overrule anthropogenic global warming?

Predicting the next solar cycle

Solar prediction is a problematic exercise as there are no proper physical models that allow predictions of even the next cycle. Therefore predictions tend to be based on statistical inference with little in the way of physics or modelling involved. For example, longer solar cycles tend to be followed by a weaker cycle.

The closest thing to a scientific consensus on solar prediction comes from the Solar Cycle Prediction Panel, consisting of members of NASA, NOAA, ISES and other US and International representatives. In March 2007, they released a consensus statement for the amplitude of the upcoming cycle 24. Their position:

"In light of the expected long interval until the onset of Cycle 24, the Prediction Panel has been unable to resolve a sufficient number of questions to reach a single, consensus prediction for the amplitude of the cycle. The deliberations of the panel supported two possible peak amplitudes for the smoothed International Sunspot Number (Ri): Ri = 140 ±20 and Ri = 90 ±10."

In other words, cycle 24 may be larger or smaller. The cycle is expected to begin in early 2008 and predictions are largely speculative until it begins. The one thing we do know is when Solar Cycle 24 begins, the warming sun will add to the global warming trend as it heads towards solar maximum, nearly doubling the projected temperature rise from greenhouse gases from 2008 to 2012 (Camp 2007).

Long term predictions of solar activity

Predicting solar cycles further into the future is even more speculative. A recent paper Grand minima and maxima of solar activity: New observational constraints (Usoskin 2007) found solar variations are defined by chaotic processes, casting significant doubts on long-term predictions using multi-periodic analyses. The sun is currently in a period of "grand maxima" where activity is higher than usual. Usoskin 2007 found the termination of a grand maximum is a random process. In other words, the timing of when the sun will start cooling from it's current 'grand maximum' state is random and hence prediction is problematic.

What if the sun did go through another Maunder Minimum?

However unlikely and difficult to predict, imagine for the sake of argument that the sun does go through another Maunder Minimum over the next century. What effect would this have on Earth's climate? The difference in solar radiative forcing between Maunder Minimum levels and current solar activity is estimated between 0.17 W/m2 (Wang 2005) to 0.23 W/m2 (Krivova 2007).

In contrast, the radiative forcing of CO2 since pre-industrial times is 1.66 W/m2 (IPCC AR4), far outstripping solar influence. And that's not including the extra CO2 to be added to the atmosphere in upcoming decades. In other words, the warming from CO2 dwarves any potential cooling even if the sun was to return to Maunder Minimum levels.

Printable Version

Further reading

Tamino discusses predictions of future solar activity in Solar Cycle 24.

Acknowledgements

Many thanks to Sami Solanki for his invaluable advice and feedback as well as John Cross for his very helpful comments.

Comments

Comments 1 to 22:

  1. Hi John: Thanks for the thanks (although I will hasten to point out that all I did was offer some minor comments). I am especially delighted to me mentioned in the same acknowledgement as Dr. Solanki. I don't know if Dr. Solanki reads this blog, but if he does I would like to say that I have been reading his papers since I came across the Harold Jefferys Lecture that he did about 4 years ago. Very interesting work!

    Regards,
    John
  2. Re: "What if the sun did go through another Maunder Minimum?" Not IF but When. It's part of the long term climate cycle.
  3. Actually we can't head into an ice age at this point in time because we are already in one. Technically this is an interglacial period within the current ice age, ie. this is not "Earth Normal" climate, which is much hotter. Interglacial means "between glacations" and is about as unstable a climate as possible on this planet. That is assuming that it is an interglacial rather than the ice age ending (far worse for us). It also assumes that another glacation will occur.
    Looking at graphs of prior interglacials and glacations there is a particular constant: it warms slowly for thousands of years then cools rapidly (it looks very similar to a sawtooth inventory graph).
    Another fact is that CO2 has been very high when it suddenly became very cold (it did nothing to stop the glacations). So be afraid, be very afraid.
  4. Quietman: That's simply not true.

    The glacial cycles of the last 450'000 years have consisted of long periods of slow cooling, followed by rapid warming. (http://commons.wikimedia.org/wiki/Image:Ice_Age_Temperature.png - please note that present day is to the left).

    This rapid warming is believed to be started by small changes in solar forcing (see Milankovitch cycles: http://en.wikipedia.org/wiki/Milankovitch_cycles) which is enough to start positive feedback spirals: warmer -> more greenhouse gases -> even warmer...

    Since we've recently come out of an glacial period, temperature is basically is as it gets and should be slowly decreasing (on a long timescale) until we reach the next glacial period. But instead, anthropogenic releases of greenhouse gases have started the process of warming. The amount of released GHG so far is enough to keep the planet warming for a long time (but of course, with possible micro trends of cooling) and we've soon reached a level where positive feedback spirals kick in, meaning that temperature will continue to rise even if we would stop our own releases of GHG.
  5. should've been: "... is basically as high as it gets ..."
  6. Maunder minimum...solar radiation ( and I deliberately use that term) drops between .17 and .23 W/m2; the suggestion is that these changes are insufficient to account for glaciation periods, or , if they are responsible, the system must be pretty thermally unstable.
    What was perihelion at this time? Orbital eccenticities have FAR greater effects on the amount of radiation recieved (between 6 -7% depending on source)than solar variations.
    What other factors were different then as opposed to now? You cannot isolate one component of a system and use it to determine an end result. You have to include all factors.
    My general conclusions from what I have read and what I have tried to model, is that the 'normal' state of the earth is "cold". That the warm phases are the anomalies.
    I accept this is MY opinion, but given the choice between a longer, warmer interglacial period or an earlier decline into one, I think I would opt for the warmth; life ( of all kinds) flourishes better in warm climates
  7. Why am I not surprised that the snapshot used by "Image from Global Warming Art" is different from everyone elses? It's called cherry picking.
  8. To clarify, Look at the 5 million year chart instead. The highs and lows of 450 K years are only oscillations of a gradual warming trend for 5 million years.
  9. The O18 concentration in bottom-dwelling foramanifera is used as a proxy for surface climatic conditions: eg a warmer climate produces more dead bodies drifting to the sea bed which allows the organisms there to multiply and 'trap' more O18. There are some difficulties with this, namely, you need prior data on the level of O18 or C13 at 'ground zero'. Also how do you compute the time lags involved? Slide the graph around until there seems some kind of match to glacier records?
    How do you accomodate variations in surface species numbers due to local climate?
    Are 57 core samples sufficient to give a general trend?

    http://en.wikipedia.org/wiki/Paleothermometer
  10. "The difference in solar radiative forcing between Maunder Minimum levels and current solar activity is estimated between 0.17 W/m2 (Wang 2005) to 0.23 W/m2 (Krivova 2007)"

    Wang 2005: "The increase in cycle-averaged TSI since the Maunder minimum is estimated to be ~1 W/m2" (instead of 0.17 W/m2?)

    Krivova 2007: "[The model predicts] an increase in the solar total irradiance since the Maunder minimum of 1.3^+0.2_-0.4 W/m2" (instead of 0.23 W/m2?)
  11. I am a novice here but I have noticed a lot of technical jargon that I don't understand.

    "Al Gore" etc thinks it is going to get warm.

    The "skeptics" say it is going to get cold.

    I think that if I lived in the NH I would make sure I have got some warm clothes.

    The bottom line is that all our heat comes from the Sun. If it cools down so does Earth. Any variances due to different Ocean Currents, Magnetic Fields etc are only releasing stored energy from the Sun.

    At the end of the day this planet will be a Dead Rock circling a spent Sun.

    Lets hope it warms up, CO2 increases, Plants grow and life becomes comfortable for a while. The alternative is not nice.
  12. Nor is a seven metre rise in sea levels. Where are all the people who live within ten miles of the coast going to live?

    I doubt the dinosaurs worried too much about how much land they had available or how many times they were flooded out or how many died in forest fires or died of thirst.
  13. Samboc:
    Don't worry about the sun cooling down just yet, providing it doesn't do anything silly it will follow the normal sequence for its type and increase in luminosity ( by about 10% over the next billion years).
    And you're right: warmer is better as the paleorecord shows.
    The view that sea levels will rise to the levels predicted is based on assumptions, not facts. All that water has to come from somewhere- snow,glaciers, icecaps, thermal expansion et al. There are many unresolved factors such as land rebound, greater oceanic uptake of CO2 due to rising ocean volume decreasing the GG efect at the same time as ocean warming releases more CO2...and one can go on and on.
    We currently simply do not have the ability (or data)to fully understand and accurately model the climate process, so it is not reasonable to take action that would have severe economic and societal repercussions until that time arrives.
  14. Samboc
    Well said. Warm is better than cold.
  15. sandy
    Distance to the shore is irrelevant, height above sea level is relevant. But a small factor is left out when the alarmists talk about sea level rise and that is porosity and absorbtion. The Newark Basin in New Jersey is not very much higher than sea level and yet it was swamp lands during the mesozoic, not ocean bottom. Much of the coast that will flood is swamp land now. During the Mesozoic the midwestern US was an inland sea and remains lowland today. A catastrophic rise in sea level will most likely result in a return of the inland sea, something that alarmists fail to mention.
  16. On sea levels:

    In Australia a bed of semi-fossilised molluscs has been found above current sea level and dated at between 4500 to 6000 years old. This suggests current MSL has fallen over the last 6000yrs. since Australia is not very active tectonically.
    Wait til the creationists find that one!
    I can't remember the exact page but more detail is at John-Daly web site.
  17. Mizimi
    Plates literally float. They can shift, rise or fall. There are no true continents, what we see is a result of large pieces of lighter material breaking and mergeing or subducting. There is no real difference between sea floor and land other than elevation. So while Australia is relatively free from volcanism it is still subject to plate tectonics which are constantly active but change intensity and speed is cycles.
  18. QM: Yes, and it makes rather a nonsense of trying to assign mean sea level deviations to global warming.
    The Isles of Scilly is a group of around 50 islands some 45km south west of Cornwall, England. They have been inhabited since (at least) the bronze age, some 4000ya. At low tide, stone houses, roads and field perimeters are revealed, dating from that time, so either msl has risen a few metres in 4000yrs or the islands have sunk.....how to tell the difference?
  19. Mizimi
    I think Dr. Rhodes Fairbridge answered that question in his study of sea level cycles. It's referred to as the "Fairbridge curve" and I think wikipedia posted an explanation of how it works. I have not looked too deeply into it as I am more interested in his later "Solar Jerk" hypothesis.
  20. I heard about this on the radio last month, and this would prove that we are not the cause of climate change, and that industrialization is not harmful. Unfortunately, many people are still advocating global warming since they have their money on it.
    This seems to be the strategy for defense of these advocates: "if any part of the earth gets warmer during the industrialized age, industrialization is to blame. If the earth gets cooler, of course, industrialization is a bad thing anyway. Heads, I win. Tails, you lose!
  21. QM: have you read this, and if so, any comment?

    http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf

    How's the greehouse project?
  22. Mizimi
    Yes that was the first piece I saw that got me interested in the hypothesis. Mackey said the test period would be 2007-2011 and so far it's on the money.
    It's also the ONLY paper that predicted the cold snap, all the other articles and papers at that time said exactly the opposite. (I kept all the failed forcasts in a file to serve as bad examples for future generations).

    ps
    The green house is on hold until the ice melts. Right now I'm waiting on delivery of a larger snow blower that I can mount off the PTO on my tractor. Snow has been way too heavy for the gas fired one and too deep to plow, I have been using a bucket loader all winter to shovel it off and it's ruining my driveway. So I'm going to have to resurface it when everything finally melts. But I am planning to go with the blue plastic for the roof.

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