Via press release:
A new paper has been published in Nature Geoscience entitled ‘Dynamics of the intertropical convergence zone over the western Pacific during the Little Ice Age ’ by Hong Yan of the Institute of Earth Environment, Chinese Academy of Sciences and an international team of co-authors from the Alfred Wegener Institute (Wei Wei), Harvard-Smithsonian Center for Astrophysics (Willie Soon), Institute of Earth Environment (Zhisheng An, Weijian Zhou and Yuhong Wang), University of Hong Kong (Zhonghui Liu) and Institute of Public Affairs (Robert M. Carter). The results of the research indicate that both the East Asia Summer Monsoon and the Northern Australia Summer Monsoon retreated synchronously during the recent cold Little Ice Age in response to external forcings such as solar irradiance variation and possibly large volcanic eruptions.
The Asia-Australia monsoon covers the world’s most populated areas, and therefore understanding the factors that control monsoon-belt climatic variation through time is important for response-planning for healthy social-economic development for the globe. Many previous studies have focused on the past climate changes in the Asia-Australia monsoon area, often proposing that the western Pacific Intertropical Convergence Zone (ITCZ) or the associated rainbelt should have migrated southward during cold climate episodes, such as the Little Ice Age (AD 1400-1850). Such migrations should be associated with the occurrence of a weaker East Asian Summer Monsoon and a stronger Australian Summer Monsoon, with opposing rainfall variations between the two hemispheres.
However, hydrological records from the Asia-Australia summer monsoon area, analysed by Professor Hong Yan and his coauthors, show that southward migration of the ITCZ did not occur during the cold Little Ice Age. Instead, the hydrological data support the operation of a new dynamic mechanism named ‘ITCZ/Rainbelt contraction’ in the Western Pacific region during the Little Ice Age.
Prima facie, a southward migration of the ITCZ should result in less precipitation in the East Asia Summer Monsoon area but more rainfall in Australia Summer Monsoon area. In contrast, the Synthesis of a large set of palaeoclimatological records from across the monsoonal area establishes that the precipitation in both continental East Asia and northern Australia decreased synchronously during the Little Ice Age. The unusual spatial variation in paleoclimate records therefore documents a distinctly different rainfall pattern that violates the former expectation of ITCZ southward migration. Furthermore, comparison of these results with solar records indicates that a relationship exists between the rainfall changes and Total Solar Insolation.
To explain these changes, the scientists propose an alternative dynamic scenario which they have tested using process-based climate modeling. Rather than strict north-south migration, the multi-decadal to centennial change for the western Pacific Intertropical Convergence Zone can excitingly be shown to have contracted or expanded in parallel with solar irradiance variations. This new understanding clearly adds to the richness of mechanisms by which the Earth climate system can vary naturally and significantly over periods between a few decades and up to a century in length.
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The research was found by the Ministry of Science and Technology of China, the Natural Science Foundation of China and the Chinese Academy of Science.
Note: headline was edited about 20 minutes after publication to add lead author Hong Yan, an oversight on my part – Anthony
As I have said before…always have been a fan of Soon and Carter. They publish climate reality and have become my personal appeal to authority. These folks know of what they speak. Year, after year….they continue to publish objective, well researched solid work. (Just my personal opinion)
One must rule out the first encountered pathology. If we do not have records of the teleconnected oceanic/atmospheric conditions present during the period of time under question, to point to solar connections is premature. Due to internal fluid dynamics and other Earthly parameters present at the time under study, it makes sense that internal oscillations, prodded to extend or contract by internal events such as volcanic veils or land bridges coming or going, should be ruled out first. The study seems too willing to look outside a complicated internal system. Not impressed.
Yes, there was an LIA. Yes there was an ITCZ contraction as proposed. Not sure I can see a solar connection. There is no real proof that CO2 effects the atmosphere, purely speculation. No real proof that the sun does either. I tend to agree with Pamela that the internal dynamics of the earth system need to be sorted out first before looking at some vague external factors.
Alex
March 11, 2015 at 11:03 pm
Sorry, but when CO2 can be considered as either having or not an effect in climate and atmosphere, definitely the CO2 is not an external factor, either vague or not is indeed an internal factor….
cheers
I was using the term external (for CO2) in this case ,as it is considered a ‘forcing’. In my mind I see a forcing as an external thing.
I am implying that it doesn’t make much difference if you increase or decrease the population of a city by 1%. However it makes a big difference if the river the city depends on is diverted.
Sentence 1 is the effect of CO2 and the sun.
Sentence 2 is the fluid dynamics etc. of the earth.
@alex: “There is no real proof that CO2 effects [sic] the atmosphere…”
Hmm… Might you do us the kind favor, then, of giving us your considered and irrefutable refutations of the Tyndall equations — just for starters, of course, seeing as how they are quite venerable, and in needed the tuning that they’ve received over the past 100-plus years. But I’m sure we’d all be curious to hear your specific and testable objections to their assertions.
Or perhaps we should start you out with something simpler — how about defining what you believe to be specific weaknesses in CMIP5 simulations and suggesting improvements, m’kay?
Haha!
It’s an assertion and not irrefutable proof.
Far be it for me to argue with the ‘learned gentlefolk’ and their models. I just note that temperature remains the same over 18 years while CO2 increases.
Tyndall? Do you mean ‘why is the sky blue?’. What does that have to do with anything?
There is no point discussing and/or suggesting anything to these ‘learned folk’ when they add albedo/ emissivity to neat equations (S-B etc.) when everyone who bothers to look up the definition of these values will see that it is only meant as an approximation. So you end up multiplying everything by point ‘ish’.
So cool. I don’t get involved in a battle of wits with an unarmed man.
Rik, may I commend you on not hiding behind a pseudonym and that, of itself, makes your comment worthy of a considered answer. To be scientifically literate we must accept that no theory can be proven in any absolute sense. There is always room for doubt and for (even) fundamental revision. It is also, as Lakatos, Kuhn and others convincingly argued, impossible to disprove a theory (the presence of ceteris paribus clauses and the jointness problem to name just two substantial issues that all scientists confront). This is all well trodden ground. The point about the impact of CO2 on global temperatures is a strong conjecture and, from a theoretical perspective, it is highly plausible. The problem is unambiguously detecting the effect in real data. Without doubt the planet has undergone some significant warming over the industrial period but how much is empirically very hard to determine. The association between emissions and temperature change is statistically very weak, even a casual look at the two time series suggests that the chances of establishing correlation are non-existent (unit root problems etc). Correlation does not mean causation, but without correlation demonstrating causation is extremely difficult and hence we have got ourselves into a wicked attribution problem. Fingerprint studies, climate modelling and all the rest are all attempts to nail the problem but all have very significant issues. We are then confronted with the problem of the ‘pause’ and the divergence of temperature series from modelled expectations and to deny its extent and significance is, to my mind, just silly. You see Rik, skepticism is a virtue in any scientific endeavour and the statement ‘there is no real proof…’ is correct. There is, I believe, good support for, but no proof of, a link between anthropogenic emissions of CO2 and global temperature change – but I am skeptical that the conjecture of a strong positive feedback effect has been demonstrated and so my position is that we have far more urgent problems to deal with. That seems to me to be a sensible position for any skeptic with respect to this issue to take.
Professor Bob Ryan
Eloquent.
I responded tersely because I felt under attack for something I didn’t actually say.
@ur momisugly Bob Ryan: Thanks for your thoughtful response — it’s always a relief to hear from someone whose response isn’t mailed in an ad hominem envelope.
I concur that an association is not a proof, but I disagree with your assertion that the “association between emissions and temperature change is statistically very weak” — weakness, in this case, is a judgement call. And, of course, I’d be a fool to argue against the assertion that “skepticism is a virtue in any scientific endeavour and the statement ‘there is no real proof…’ is correct.” But as a member of the scientific community, you must also understand that “real proof” is a rare bird, indeed — especially in as complex a system as global climate.
The question at hand, I fear, is at what point in the accumulation of evidence do the ramifications of a nascent “proof” become a cause for action, particularly when the effects being described, modeled — and yes, at times merely postulated — become sufficiently dire? Personally, my reading of the literature leads me to the conclusion that there is enough solidly accumulated, well-analyzed, and irrefutable evidence to say that the gamble of waiting for “real proof” — or, for that matter, for “real refutation” — it too great. And, as you well know, my position is in line with the majority consensus — and you appear to be too intelligent a man to engage in such balderdash as assertions that the general consensus is either 1) motivated by careerist grant seekers, b) driven by echo-chamber, herd instinct, or iii) not a consensus at all, but rather a left-wing, media-driven plot to strip away freedoms — the whole ridiculous “watermelon” meme. No, the climate-science community is replete with serious truth seekers attempting to provide policymakers with clean data and well-thought-through information. My recent attendance at the American Geophysical Union’s December meeting, fore example, brought me in contact with thousands of like-minded scientists — and even with my bullshit detectors set to stun, I couldn’t find a charlatan among them. Some dim bulbs, to be sure, but in any gathering of 24,000 souls, there will be some silliness…
Finally, speaking of “unambiguously detecting the effect in real data,” I assume you’ve read of the work of Daniel Feldman at al. at the Lawrence Berkeley National Laboratory (http://newscenter.lbl.gov/2015/02/25/co2-greenhouse-effect-increase/). A small step, to be sure, but solid experimental data, well-analyzed.
Something’s gotta die as we’re being overrun by species contrary to green mythology-
http://www.dailymail.co.uk/sciencetech/article-2990729/From-frilled-shark-frogfish-finding-four-new-sea-creatures-day-Scientists-uncover-1-451-new-species-ocean-past-year-alone.html
Fancy fish and chips for dinner?
On second thoughts perhaps not as they must all be from outer space since the science is settled.
Funded by the Chinese Communist Party! In that case Obama, Boxer. Markey and Co will approve – unconditionally!
@BillTheGeo:
Deep, sir, deep. This is, after all, a rather important subject — is it too much to ask you to shelve your puerile, sniggling, ad hominem attacks, and instead provide well-supported arguments based on solid data and well-informed analysis?