Asian climate variability and dynamics across early-to-middle pliocene warm period provide clues for future climate change


Peer-Reviewed Publication

CHINESE ACADEMY OF SCIENCES HEADQUARTERS

IMAGE: FIELD PHOTOGRAPH OF THE SHILOU RED-CLAY SEQUENCE FROM THE EASTERN CHINESE LOESS PLATEAU view more 
CREDIT: AO HONG

A recent study by an international research group led by Prof. AO Hong from the Institute of Earth Environment of the Chinese Academy of Sciences has revealed Asian climate variability and dynamics across the early-to-middle Pliocene Warm Period, thus providing clues for future climate change.

The joint research team comprised scientists from China, Australia, Germany, France, Netherlands, and the USA. The group’s findings were published in Nature Communications on Nov. 26.

The early-to-middle Pliocene Warm Period between ~5 and 3 million years ago (Ma) that preceded Northern Hemisphere glaciation was the most recent period of persistently warmer-than-present conditions. During this warm interval, Earth’s mean annual surface air temperatures were ~2–4° C higher than today, the Northern Hemisphere was largely ice-free, global sea level was ~20–25 m higher than today, and atmospheric CO2 concentrations were comparable to present-day levels.

The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report projects that present-day high-CO2, warm conditions will continue for a long time and likely intensify, which may shift Earth’s future climate to a warm state similar to the early-to-middle Pliocene Warm Period.

“Understanding climate variability and dynamics during the early-to-middle Pliocene Warm Period is significant to better projecting future climate responses to sustained global warming,” said Prof. AO, the principal investigator of the study.

The aeolian loess/red-clay sequences on the Chinese Loess Plateau (CLP) provide a unique high-resolution archive of terrestrial climate variations continuously spanning the last 25 million years (Myr). The researchers established ~4.7-Myr-long summer monsoon records (Al/Na, Rb/Sr, and lightness) continuously spanning the period from ~8.1 to ~3.4 Ma at ~1–2-thousand-year (kyr) resolution from the Shilou aeolian red-clay succession on the eastern CLP. These records reveal the details and forcing mechanisms of Asian climate variability at an orbital timescale as well as longer trends from the late Miocene to the mid-Pliocene.

The high-resolution Al/Na, Rb/Sr, and lightness records show that the Asian summer monsoon had prominent 405-kyr and ~100-kyr periodicities between 8.1 and 3.4 Ma, consistent with a dynamic response to eccentricity modulation of solar insolation, a low-latitude forcing.

Surprisingly, obliquity cyclicity is only weakly expressed in those monsoon records, although it dominated the Antarctic glacial cycles throughout the late Miocene–Pliocene. Thus, it appears that orbital-scale Asian summer monsoon variability responded more dynamically to insolation forcing than to ice-sheet forcing during the warmer-than-present late Miocene to the mid-Pliocene when the Northern Hemisphere was largely ice free and continental-scale ice sheets only developed in Antarctica.

By integrating their new CLP red-clay, summer monsoon records with existing terrestrial records, land-sea correlations, and climate-model simulations, the research group found that CO2-induced global warming across the Miocene–Pliocene boundary (MPB) at ~5.3 Ma both increased summer monsoon moisture transport over East Asia, and enhanced aridification over large parts of Central Asia by increasing evaporation.

This finding offers palaeoclimate-based support for “wet-gets-wetter and dry-gets-drier” projections of future regional hydroclimate responses to sustained anthropogenic forcing.

The observation of continental-scale hydrological gradient intensification over Asia linking to global warming across the MPB has significant implications for future Asian climate responses to sustained high anthropogenic emissions.

“It implies that along with long-term sustained global warming, most East Asian monsoon regions may become even wetter than they are currently, with increasing flooding risks, while Central Asia may become even drier, with more persistent droughts and desertification in future,” said Prof. JIN Zhangdong, a coauthor of the study and director of State Key Laboratory of Loess and Quaternary Geology.

This study was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology of China, and the National Natural Science Foundation of China.


JOURNAL

Nature Communications

DOI

10.1038/s41467-021-27054-5 

ARTICLE TITLE

Global warming-induced Asian hydrological climate transition across the Miocene–Pliocene boundary

ARTICLE PUBLICATION DATE

26-Nov-2021

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Jay Willis
November 30, 2021 10:12 am

“By integrating their new CLP red-clay, summer monsoon records with existing terrestrial records, land-sea correlations, and climate-model simulations, the research group found that CO2-induced global warming…”

It was all going so well until this. How can these people so misrepresent the philosophy of science in this way. If you introduce a model which is a hypothesis that CO2 causes warming, you cannot describe the product of that model as if it were an observation from nature. It’s bollox.

Last edited 1 month ago by Jay Willis
Ron Long
Reply to  Jay Willis
November 30, 2021 11:48 am

Get them, Jay! Some good data thrown under the bus for the CAGW crowd to ignore. Modern Science seems to be find some complex data and interpret it to suit the funding environment, game on! If the CO2 levels were similar to today, and sea level was 25 meters higher, why are we discussing a possible 0.3 meter rise?

n.n
Reply to  Jay Willis
November 30, 2021 12:49 pm

Conflation of logical, social, etc. domains is an imperative of the modern model.

Reply to  n.n
November 30, 2021 1:57 pm

China needs more people…”climate migrants ” should move there now….and no virus problem there according to their official numbers.

AndyHce
Reply to  Anti_griff
December 1, 2021 10:55 pm

but will China have enough government appointed “guests” to live with each immigrant family?

Duane
Reply to  Jay Willis
November 30, 2021 5:27 pm

Going back millions of years, whatever they used as data sets could not possibly have such precision to prove that CO2 increases resulted in higher temps as opposed to higher temps causing increased CO2. That level of precision is available in far shorter timescales from ice core sampling within the last glaciation cycle measured in tens of thousands of years … in which case the ice core data shows that warming preceded CO2 increases, not the other way around.

The explanation for why a warming earth causes atmospheric CO2 to rise is simple physical chemistry: a rise in oceanic temperatures increases the gas or vapor pressure of dissolved gases, such as CO2,, and reduces the solubility of gases in water. CO2 transfer from oceans to the atmosphere thus increases resulting in a higher equilibrium concentration of CO2 in air.

Thomas Gasloli
Reply to  Jay Willis
November 30, 2021 6:29 pm

CO2 climate “science” has been & will always be circular reasoning and garbage models because it just simply is not science.

Gary Pearse
November 30, 2021 10:22 am

So Middle Pliocene was 2-4°C higher than today with about the same CO2 in atmosphere as now. That kills the CO2 temperature control knob, surely is one of the conclusions supported. The other is natural variability is huge!! Why would real scientists then connect this up with the already falsified IPCC notion? Wake up, you are supporting the clear conclusion that nat variability is the main driver.

Gary Pearse
Reply to  Gary Pearse
November 30, 2021 10:40 am

It has been mentioned that many climate studies done by the consensus really support more obvious alternative conclusions that conflict with the ‘chosen’ ones. It would be interesting to analyze studies that appear to have been well designed and see if they, too, have more readily obvious conclusions than the authors present.m, as in the present study.

Here we have desertification in one region, development of monsoonal severe weather at another, seas rising several meters – big, big climate change without CO2 levels greater than now. Methinks sceptics natural variation wins out here. No humans were disturbed in this climate weirding.

Retired_Engineer_Jim
Reply to  Gary Pearse
November 30, 2021 1:06 pm

But this time it is different.

Reply to  Retired_Engineer_Jim
November 30, 2021 5:34 pm

And it’s worse now because they didn’t have an existential crisis then ( as the phrase hadn’t been invented ) !

November 30, 2021 10:28 am

Let’s see. 25 million years worth of clay at 1,000 year resolution. That is 25,000 slices of clay., which we measure some chemicals in today, after they have been there for millions of years.

To tell us something useful about the next 100 years. Surely this is just stupid.

TonyL
Reply to  David Wojick
November 30, 2021 11:41 am

But just think, this work well informs us about the climate 5 million years into the future.
We need a few million years for continental drift to rearrange the face of the Earth, and critically to allow the reestablishment of the worldwide equatorial current in the worlds oceans. This will finally put an end to the dreadful ice age we are now it. With that done, we will be able to predict the climate on 10k year timescales based on orbital mechanics.

What’s not to love?


Rud Istvan
Reply to  David Wojick
November 30, 2021 12:30 pm

Just a bit of a resolution problem.

Dave Fair
Reply to  David Wojick
November 30, 2021 2:36 pm

That’s 1,000 to 2,000 resolution. How do they determine CO2 leads temperature?

Jim Gorman
Reply to  Dave Fair
December 1, 2021 6:37 am

You really can’t say which came first. The best you can say is that temperature and CO2 appear to be uncorrelated.

Peta of Newark
November 30, 2021 11:02 am

<gentle knowing smile>

The Chinese Loess Platform was/is a thing entirely constructed via the process of Soil Erosion

carbon oxide was ‘slightly incidental’ – it came along for the ride
As it does now – to three decimal places of zero incidentalness

Rud Istvan
Reply to  Peta of Newark
November 30, 2021 12:35 pm

Loess is aeolian (wind borne), in this case mostly from the Gobi desert. It is defines as about 20% clay with the rest equal parts of sand and silt. Dunno how a clay fall forms, cause the paper sounds like 100% clay. And for sure both sand and clay are formed by chemical weathering of igneous rock.

Redge
November 30, 2021 11:19 am

From the introduction of the paper:

The early-to-middle Pliocene Warm Period was the most recent period of persistently warmer-than-present conditions. During this warm interval, the Northern Hemisphere was largely ice-free and atmospheric CO2 concentrations were comparable to present-day levels

So much for the control knob

MS25
November 30, 2021 11:50 am

The Climate Optimum a few thousand tears ago was the most recent period of persistently warmer-than-present conditions.
comment image

Chris Hanley
Reply to  MS25
November 30, 2021 12:38 pm

And empirical evidence suggests that a series of brief inter-glacial periods will most likely continue interrupting long glaciations in any time frame even remotely of interest.

Last edited 1 month ago by Chris Hanley
Thomas Gasloli
Reply to  Chris Hanley
November 30, 2021 6:33 pm

But that won’t provide a justification for a $12500 subsidy for lousy Detroit EVs.

PCman999
Reply to  MS25
November 30, 2021 2:46 pm

I’d even say that anything earlier (more) than 800 yrs ago was warmer based on that reconstruction, however I have doubts because the so-called Dark Ages and the Bronze Age collapse don’t really show – unless the swift up-and-down in temps was the culprit, which makes sense too.

Doug Danhoff
November 30, 2021 12:09 pm

I quit reading at the point where they assumed man made warming …If it is so obvious to them that it can be assumed, why have they never presented proof ..or even a plausible correlation to man and temperature …and that brings up the biggest attack to physics…one I can not tolerate , … Co2 follows temperature . This concept is as solid and as close to a LAW of physics that we have .
putting the wagon in front of the horse negates any science that surrounds it …no matter how well crafted

Joseph Zorzin
November 30, 2021 12:13 pm

“obliquity cyclicity”

say what?

November 30, 2021 12:22 pm

“The whole Net Zero campaign is founded on the self delusions and confirmation bias of the academic establishment consensus model forecasts . The main stream Media notably the BBC ,Guardian, NBC ,ABC, CBS,PBS have been the greatest sources of false news. They have produced a generation of scared and psychologically disturbed teenagers and green fanatics who believe that the world has no future if fossil fuels continue to be used. The effect of C02 on temperature is immeasurably small. There is no CO2 caused climate crisis. It is left to sites like WUWT and the Blogosphere in general to question and discuss the basic science on which the disastrous Net Zero policies are based. See my paper at
“Net Zero threatens Sustainable Development Goals”
https://climatesense-norpag.blogspot.com
 Excerpts:
“Abstract
This paper begins by reviewing the relationship between CO2 and Millennial temperature cycles. CO2 levels follow temperature changes. CO2 is the dependent variable and there is no calculable consistent relationship between the two. The uncertainties and wide range of out-comes of model calculations of climate radiative forcing arise from the improbable basic assumption that anthropogenic CO2 is the major controller of global temperatures. Earth’s climate is the result of resonances and beats between the phases of cyclic processes of varying wavelengths and amplitudes. At all scales, including the scale of the solar planetary system, sub-sets of oscillating systems develop synchronous behaviors which then produce changing patterns of periodicities in time and space in the emergent data. Solar activity as represented by the Oulu cosmic ray count is here correlated with the Hadsst3 temperatures and is the main driver of global temperatures at Millennial scales. The Millennial pattern is projected forwards to 2037. Earth has just passed the peak of a Millennial cycle and will generally cool until 2680 – 2700. At the same time, and not merely coincidentally, the earth has now reached a new population peak which brought with it an associated covid pandemic, and global poverty and income disparity increases which threaten the UN’s Sustainable Development Goals. During the last major influenza epidemic world population was 1.9 billion. It is now 7.8 billion+/. The establishment science “consensus” that a modelled future increase in CO2 levels and not this actual fourfold population increase is the main threat to human civilization is clearly untenable. The cost of the proposed rapid transition to non- fossil fuels would create an unnecessary, enormously expensive. obstacle in the way of the effort to attain a modern ecologically viable sustainable global economy.  We must adapt to the most likely future changes and build back smarter when losses occur.

commieBob
November 30, 2021 12:26 pm

“Understanding climate variability and dynamics during the early-to-middle Pliocene Warm Period is significant to better projecting future climate responses to sustained global warming,” said Prof. AO, the principal investigator of the study.

I call B.S. The conventional explanation for the current ice age is that the Isthmus of Panama closed and changed ocean circulation. link

Since a major factor in the global climate has changed, one can’t assume that what happened in the Pliocene will shed any light on what happens to the future climate.

Last edited 1 month ago by commieBob
Rud Istvan
Reply to  commieBob
November 30, 2021 12:38 pm

But but but—the Panama Canal reopened the Isthmus (ok, a teeny tiny bit using locks) so that is why global warming after the Panama Canal.

Reply to  Rud Istvan
November 30, 2021 1:53 pm

Well, the canal works with the large lake being above sea level….ships are raised by locks to the lake level and then back down at the other end….so not much passage of seawater.

Drake
Reply to  Anti_griff
November 30, 2021 2:50 pm

Rud didn’t think he needed the sarc tag. But really, co2 started rising more rapidly when it opened, so the correlation is obvious.

Reply to  commieBob
November 30, 2021 12:46 pm

CommieBob

You beat me to making the same point.
Ocean currents rule the climate, the winds are a consequence and not a cause of climate change.

The final closure of the Isthmus of Panama at ∼3.5 Ma divided the American tropical ocean into two separate and different oceanographic regions.

Coates A.G et al. 1992 Closure of the Isthmus of Panama: The near-shore marine record of Costa Rica and western Panama.GSA Bulletin (1992) 104 (7): 814–828.

Abolition Man
Reply to  Philip Mulholland.
November 30, 2021 1:17 pm

Philip,
These authors have determined that the PDO, ENSO, and the IOD are much too difficult to program into their models; so, therefore, they can not exist or affect the climate in any meaningful way!
All geologic records and proxies arguing for their existence are mere subterfuge from the Great Demon; CO2! Just believe it!!

PCman999
Reply to  commieBob
November 30, 2021 2:52 pm

From reading your link it’s more likely the joining of the 2 continents is helping to keep the Arctic warmer than it’s southern counterpart. Just look at the huge Gulf Stream funneling warm water to Scandinavia.
However I’d trust your analysis of the situation over the current crop of climate alarmist scientists any day.

Last edited 1 month ago by PCman999
fretslider
November 30, 2021 12:31 pm

“ This finding offers palaeoclimate-based support for “wet-gets-wetter and dry-gets-drier” projections…”

Nuff said

Bill Treuren
Reply to  fretslider
November 30, 2021 1:09 pm

Is that not the Willis emergent process in play.
So they sidestep the tropical temperature then and talk global average and then explain no ice at Arctic.
The best bit is, not gross solar radiation due to orbits but due to solar variation. Me thinks with spectral content a likely variable as a consequence.

25M higher sea level would that breach the Panama thus allowing a reduced surface skimmed ocean circulation and then during a variable cold period a sudden loss of flow then fast cooling as the ocean flow is terminated due to sea level.

PCman999
Reply to  fretslider
November 30, 2021 2:57 pm

More like it offers support to the alarmists’ pants getting wetter.

n.n
November 30, 2021 12:48 pm

Temperature perturbations can be completely explained through natural processes and phenomenon. Climate has varied over the arbitrary 30-year period, less, more, too. That said, emit, recycle CO2 for a greener environment and carbon-based flora, fauna, and people/babies, too.

Vuk
November 30, 2021 12:50 pm

Another article was published today in the Nature communication, that Guardian goes to town on.
“Rain to replace snow in the Arctic as climate heats, study finds
Climate models show switch will happen decades faster than previously thought, with ‘profound’ implications
Rain will replace snow as the Arctic’s most common precipitation as the climate crisis heats up the planet’s northern ice cap, according to research.”
Looks like Arctic Ocean is going to be flooded, Vlad the Terrible has wasted billions of rubbles on those ice breakers.
https://www.theguardian.com/environment/2021/nov/30/rain-replace-snow-arctic-climate-heats-study

Nature paper title says: “New climate models reveal faster and larger increases in Arctic precipitation than previously projected”
Ah, those models are getting faster and larger, ….. must be something to do with all this new gender thingy that has taken over the mass media.
https://www.nature.com/articles/s41467-021-27031-y

Bill Treuren
Reply to  Vuk
November 30, 2021 1:11 pm

Its ice till 0C a bit to go. Again and so what!!

Jim Gorman
Reply to  Bill Treuren
December 1, 2021 7:35 am

I think this is what a lot of folks miss. The temperature difference between snow and rain is very small. The change happens at the margins geographically. That borderline may move over time but it isn’t a massive change over the entire area all at once, regardless of what the movies show.

PCman999
Reply to  Vuk
November 30, 2021 3:01 pm

“Climate models, that failed to predict the current climate years ago, make a bunch of b.s. predictions for the future, but we print the climate doom porn because we’re desperate for readers”

Thomas Gasloli
Reply to  Vuk
November 30, 2021 6:36 pm

And yet none of our “elites”’are rushing to snatch up all that beach front real estate.😁

n.n
November 30, 2021 12:53 pm

Russian/Asian climate variability varies from permafrost to transient blocking events (impulses in the unobserved record) and above “normal” temperatures that frighten the horses, chickens, and people of carbon (POC), too.

Rich Lambert
November 30, 2021 2:03 pm

It is interesting that people can study millions of year old rocks and soil from a few areas and arrive at the Earth’s mean annual surface air temperatures. There evidently is no need for all the computers to derive the mean annual surface air temperature now.

Jim Gorman
Reply to  Rich Lambert
December 1, 2021 8:07 am

I’ve pointed out the same thing about the use of “proxies”. You can’t say that one doesn’t represent the whole globe and then turn around and say that another one does. Height of hypocracy!

Mike Dubrasich
November 30, 2021 2:18 pm

It was warmer, a lot warmer, and the oceans didn’t boil away into Outer Space? But but but NASA experts say they will, or did, or something TOTALLY DIRE!

Stop the presses! Do these wild and crazy sexperts mean to imply that a warmer world wasn’t a catastrophic disaster with flaming skies, Martian droughts, extinction of all life, and other unpleasant stuff?

Are there any other Scientesticles who hypothesize that Life Itself can survive a 2°-4°C warmer Planet Earth? If so, they must be Cancelled immediately. This nutty Warmer Is Okay, Possibly Even Better rap has to be snuffed in the bud or else the Hotpocalypse Extinction Panic will wither and die, and then what will our Glorious Leaders do?

Tom Abbott
Reply to  Mike Dubrasich
December 1, 2021 3:57 am

“TOTALLY DIRE!”

That made me laugh! 🙂

PCman999
November 30, 2021 2:32 pm

One thing that has always bothered me about past warm period paleo reconstructions, is how miniscule the difference in temperatures was from today, and yet big dramatic difference in the visible climate. E.g. the article mentions that N. America was largely ice free, and the Earth about 2-4 degrees warmer. Seems like the paleo recon might be very conservative.

Jim Gorman
Reply to  PCman999
December 1, 2021 8:19 am

Most reconstructions don’t do absolute temperatures. They do so called “anomalies”. What most people don’t realize is that reconstructions only show changes, and not absolute temps. That is why appending current measured temps onto reconstructions is such a large error. You have no idea if the baselines match at all.

The same error occurs when combining reconstructions with a 1000 year resolution with current annual temps. If each point in a reconstruction is 1000 years, then a current point should be the average of the last 1000 years, i.e., from 1121 to 2021. In other words one data point encompassing The Little Ice Age and current warming.

ResourceGuy
November 30, 2021 2:35 pm

I thought loess deposition was subject to wind variability much like grid operations today.

Sara
December 1, 2021 7:43 am

OH, let’s see: that red loess clay was used by Neolithic potters to make POTS, which means it must have some beneficial qualities about it. Mix it with the right amount of water, form the clay balls to do some hand-made creations like bowls and small cups (for drinking water and maybe fermented wheat – oh, wait – the fermented water [beer] was the Middle East – sorry) and it proved to be useful for a long time.

Some bright person put the dried clay bowls near or into a fire and they sort of hardened, and — well, clay is clay and you make things with it, so aside from its usefulness as kitchenware, what exactly prods these geniuses to decide that it’s a weather/climate marker, other than getting grants money from Xi JinPing?

Thanks for the article. It really does point out the silliness involved in trying to jump on the climate bandwagon and “fit in”.

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