Claim: New mathematical method shows how climate change led to fall of ancient civilization

Chaos paper by RIT Assistant Professor Nishant Malik applies method to Indus Valley Civilization


Research News


A Rochester Institute of Technology researcher developed a mathematical method that shows climate change likely caused the rise and fall of an ancient civilization. In an article recently featured in the journal Chaos: An Interdisciplinary Journal of Nonlinear Science, Nishant Malik, assistant professor in RIT’s School of Mathematical Sciences, outlined the new technique he developed and showed how shifting monsoon patterns led to the demise of the Indus Valley Civilization, a Bronze Age civilization contemporary to Mesopotamia and ancient Egypt.

Malik developed a method to study paleoclimate time series, sets of data that tell us about past climates using indirect observations. For example, by measuring the presence of a particular isotope in stalagmites from a cave in South Asia, scientists were able to develop a record of monsoon rainfall in the region for the past 5,700 years. But as Malik notes, studying paleoclimate time series poses several problems that make it challenging to analyze them with mathematical tools typically used to understand climate.

“Usually the data we get when analyzing paleoclimate is a short time series with noise and uncertainty in it,” said Malik. “As far as mathematics and climate is concerned, the tool we use very often in understanding climate and weather is dynamical systems. But dynamical systems theory is harder to apply to paleoclimate data. This new method can find transitions in the most challenging time series, including paleoclimate, which are short, have some amount of uncertainty and have noise in them.”

There are several theories about why the Indus Valley Civilization declined–including invasion by nomadic Indo-Aryans and earthquakes–but climate change appears to be the most likely scenario. But until Malik applied his hybrid approach– rooted in dynamical systems but also draws on methods from the fields of machine learning and information theory–there was no mathematical proof. His analysis showed there was a major shift in monsoon patterns just before the dawn of this civilization and that the pattern reversed course right before it declined, indicating it was in fact climate change that caused the fall.

Malik said he hopes the method will allow scientists to develop more automated methods of finding transitions in paleoclimate data and leads to additional important historical discoveries. The full text of the study is published in Chaos: An Interdisciplinary Journal of Nonlinear Science.


From EurekAlert!

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September 4, 2020 10:22 am

Extra, extra, read all about. Researcher turns garbage into data. Retraction to follow at 9:00.

September 4, 2020 10:23 am
Reply to  Vuk
September 4, 2020 1:33 pm

That’s great. In Lancet too – oh, the irony, or is it orangemanbad again ? I can’t keep up.

……. and back on topic, whether or not you agree with this paper, just a reminder that this is about climate change, not phony climate change.

Reply to  Vuk
September 4, 2020 7:23 pm

Russia is interfering in U.S. elections again. Any vaccine, irrespective of where it is developed, will benefit President Trump’s re-election efforts.

J Mac
Reply to  Vuk
September 4, 2020 8:00 pm

China is also interfering in US elections and politics. In March, they deliberately locked much of intra-country travel down in China while allowing international travel of infected chinese citizens to spread the Wuhan virus. Although we are in the midst of a strong recovery now (1.4 million jobs added in August, unemployment dropped 1.8% to 8.4%), our own socialist democrats are dragging their feet on opening our economy back up state by state.

September 4, 2020 10:27 am

Extra, extra, read all about it, climate change modelling led to the fall of modern Civilisation. Meanwhile in the Covid crisis, new models show that test results actually do correlate with disease incidence. More parameters were needed.

September 4, 2020 10:29 am

Climate change has brought great misery to various societies. The Little Ice Age would be an example.

The question folks should consider is this: How is it that mankind has managed to inhabit all the otherwise inhospitable areas of the Earth? How could the hairless ape species manage to thrive in somewhere like Sweden?

A thoughtful answer to the above question should go a long way to allaying worries about climate change.

Mumbles McGuirck
Reply to  commieBob
September 4, 2020 10:55 am

The polar bear sleeps in his little bear skin
He sleeps very well I am told
Last night I slept in my little bare skin
And I caught a helluva cold

Old Grumpy
Reply to  Mumbles McGuirck
September 4, 2020 11:49 am

Would you like to sin
With Eleanor Glynn
On a tiger skin?
Or would you prefer
To err with her
On some other fur?

Michael S. Kelly
Reply to  Old Grumpy
September 4, 2020 1:01 pm

There was an old man from Nantucket…

Ron Long
September 4, 2020 10:31 am

Chaos and Nonlinear Science, from the Rochester Institute of Technology? Johnny Carson, as Carnac The Magnificent, would ask: What is the modern form of Taro Card Reading?

Reply to  Ron Long
September 4, 2020 12:51 pm

Mr. Long,
Here is the t that you need to turn that vegetable root into a card.

Flight Level
September 4, 2020 10:32 am

Documented experimental confirmation of the numerical model described in this paper is postponed until further advice.

Ed Zuiderwijk
September 4, 2020 10:32 am

Let’s hope he has the good sense of not asking Tricky Mike for advice.

Keith Rowe
September 4, 2020 10:39 am

People live because they are able to live there. Civilization allows a buildup of technology that allows even more people to live there. Then when they aren’t able to live there they stop living there. It really isn’t that hard. The reasons for change are often because the technology they have developed aren’t good at what is happening now. I always find it odd when people say populations moved because of hardship….no – they died. There are people on the lands they might be moving to, it’s rarely the case there isn’t, and the technology they developed still isn’t applicable. And life goes on until things change again and new things are developed.

Reply to  Keith Rowe
September 4, 2020 10:47 am

We humans are only here at all because of climate(s) changing.

September 4, 2020 10:47 am

They just use a complicated method to concluded what is evident from the data. That the Harappan civilization coincides with the period of lowest (highest negative) δ¹⁸O values in the speleothem series they analyze, and therefore with the highest precipitations period. It is clearly unnecessary. Running a moving average gives the same information.

Nothing new, nothing interesting regarding paleoclimate in the article (paywalled)

I can’t judge if it is any progress in chaos mathematics, but it is not one of the featured or editors’ picked articles in the journal:
so I suspect it isn’t either.

Just copying what Eurekalert publishes without any critical analysis doesn’t cut it.

Curious George(@moudryj)
Reply to  Javier
September 4, 2020 1:38 pm

They should not have used fossil fuels.

Reply to  Javier
September 5, 2020 8:31 am

I personally think does a better job of regurgitating press releases….

September 4, 2020 10:56 am

Meh. Common sense — areas dependent on monsoons can suffer from, wait for it — changes in that monsoon. Monsoons can change from year-to-year, let alone over long periods. Doesn’t have anything to do w/CO2.

September 4, 2020 11:00 am

Damn who knew that there were people who drilled for oil and had autos 4000 years ago? I mean it had to be CO2, right? It could not have been natural variation, and the only way you get CO2 is from coal and oil.

More seriously, there is a kink in the C14 calibration curve 4000 years ago. It looks like we had a change in the amount of incoming cosmic rays. The old kingdom in Egypt collapsed at that point in time. It didn’t help that their pharaoh Pepi II was over 100 years old when he died and the succession was a mess. To this day, he retains the record for the longest reign of any king/queen in history.

The headline could also be “Man beats data till research paper appears”

Ulric Lyons
September 4, 2020 11:08 am

As with most civilisations in Europe and Asia, the Harappan civilisation was adversely impacted by the super minima of the 4.2kyr event, and more so during a pair of super solar minima from 1360 BC and 1250 BC. These grand solar minima series occur on average every 863 years.

Even the annual noise of temperature extremes can be verified.

September 4, 2020 11:14 am

Seems like the headline should be “Climate change allows civilization to grow and flourish (until it doesn’t).

Reply to  Rhb2
September 4, 2020 12:12 pm

Number of commentators on this blog have campaigned against use of ventilators in hospitals ICU’s, now they have been vindicated by the UK’s Intensive Care National Audit & Research Centre:
“Death rates among seriously ill Covid-19 patients dropped sharply as doctors rejected the use of mechanical ventilators, analysis has found.”
Dr Charlotte Summers, lecturer in intensive care medicine at the University of Cambridge, said: “Humans are designed to get the oxygen into their lungs by sucking it in – negative pressure – whereas the ventilator blows the oxygen into your lungs by positive pressure.
“Millions of years of evolution have conspired to deliver oxygen into your lungs in a very different way to a mechanical ventilator.”

Reply to  Vuk
September 4, 2020 2:19 pm

Didn’t we get the info early in MAy or June, that O2 masks are much better than these high pressure low O2 pumps ?
That’s not new, that often the patients are to compare with high mountain ills.

Alastair gray
September 4, 2020 11:38 am

You are all being unfair. It is in my opinion that in the past climate change has terminated socities as e.g. the Greenland Vikings. We should welcome studies like thiS which support the hypothesis that climate changed, changes, and will change in the future without our puny assistance. I dont think that this paper is Santer-ian shonky model pseudoscience so dont beat them down

September 4, 2020 11:51 am

Mark Twain’s quote comes to mind:
“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.“

September 4, 2020 12:00 pm

“Climate change” 5,000 years ago? The phrase is used in this paper to mean drought patterns long long ago. Had he said “drought patterns” he couldn’t get funding. But at least he used the phrase in its straightforward English language meaning, and not a euphemism for the mostly presumed effects of CO2. This is progress guys!

September 4, 2020 12:19 pm

“rooted in dynamical systems but also draws on methods from the fields of machine learning and information theory–there was no mathematical proof”

If that’s the basis, there still is no proof.

Regardless, as Willis likes to say, correlation is not causation.
Just because something happened at the same time as a suspected climate change, is not proof that the suspected climate change caused it.

September 4, 2020 12:20 pm

“His analysis showed there was a major shift in monsoon patterns just before the dawn of this civilization”

So he is saying that climate change caused this civilization.

Change is not automatically bad, I like to say “climate progress.”

September 4, 2020 12:49 pm

Not “how it led to”, but rather “how it may have led to”. Chaos establishes the limited frame of reference of the scientific logical domain.

September 4, 2020 12:49 pm

Is 2 + 2 = 5 the basis of this new method?

Reply to  BlueCat57
September 4, 2020 9:37 pm

Yes, 2 + 2 = 5 for large values of 2.

Walter Sobchak
September 4, 2020 1:08 pm

He puts a rabbit into the hat. He pulls the rabbit out of the hat, and says: “Behold, a Rabbit”

Move along, folks. There is nothing to see here.

September 4, 2020 7:48 pm

Sad that these scientists were not required to study history or do field research. They should have visited Taxila or Mohenjo-Daro in Pakistan. There are numerous historical markers in both sites that explain how a shift in the flow of Indus River drowned both cities.

September 4, 2020 11:47 pm

“analysis showed there was a major shift in monsoon patterns just before the dawn of this civilization and that the pattern reversed course right before it declined, indicating it was in fact climate change that caused the fall”

Post hoc ergo propter hoc.

Lloyd Martin Hendaye
September 5, 2020 4:37 am

Combining a “dynamic systems” approach with chaotic/fractal, random-recursive time-series is a valid means of flagging complex-interactive turning points.

In paleo-geologic context, this methodology addresses episodes such as Mesopotamia’s horrific “Dark Millennium” (4,000 – 3,000 YBP) in ecologically descriptive terms, prescribing regional hydraulic cultures’ demise and renaissance due to prevailing atmospheric/oceanic circulation patterns. (Recent studies attribute the Dark Millennium to westward shifts in Atlantic-Mediterranean currents, cooling offshore sea-surface temperatures with disastrous downwind consequences.)

In context-and-perspective, for the first time since pre-Cambrian Ediacaran Aeons, over some 3.6 million years since the Late Pliocene, Tertiary plate-tectonic shifts have driven cyclical 102-kiloyear Ice Ages interspersed with median 12,250-year interstadial remissions, including the latest Holocene Interglacial Epoch which ended 12,250 + 3,500 – 14,400 = AD 1350, coincident with a major strato-volcano eruption, a 70-year Grand Solar Minimum (AD 1350 – 1420), and a 500-year Little Ice Age ending 1850/1890 with a subsequent 140-year “amplitude compression” rebound through AD 2030. For astro-geophysical particulars, see Henrik Svensmark and Valentina Zharkova’s cosmic-radiation/Solar Magnetic Field (SMF) prognoses, plus Australian Robert Holmes’ “Mean Molar Mass” version of the Ideal Gas Law (2017), definitively refuting any –repeat, any– planet’s “greenhouse CO2” component as a climate factor.

Now 670 years into a looming 102-kiloyear Pleistocene Ice Time, entering a probable Super-Grand Solar Minimum through c. AD 2110, implacable cooling will cover 60%+ of Earth’s habitable landmasses with glaciations two-miles thick. Come 2125 or so, Luddite-Malthusian sociopaths indeed will see radical reductions in Earth’s teeming hominid population– if not by famine and disease, then due to mass-migration skyward to vast intrasolar refugia orbiting in the plane of Sol’s ecliptic.

Kevin kilty
September 5, 2020 6:42 am

Malik said he hopes the method will allow scientists to develop more automated methods of finding transitions in paleoclimate data and leads to additional important historical discoveries. …

Hooray! Automation in climate science will reduce employment there and raise productivity. Can’t hurt!

Terry Gednalske
September 5, 2020 6:52 am

I’m confused. How did they change their climate without fossil fuels? (Sarc)

It doesn't add up...
September 6, 2020 5:53 am

I’m not sure how novel this approach really is. The Santa Fé Institute has long looked at anthropolical history for examples of non linear systems that may be tipped into chaotic decline, including by documented changes in climate. The Pueblo Indian culture that surrounded their site provided a ready object of study.

September 7, 2020 3:23 am

I worked at a base metal project (before it became a mine) in Pakistan in the early ’90s, located close to two Harrapan sites: a circular defensive site on a hill-top with abundant pottery shards; adjacent to a 100m long, 30m high dam built across a now dry drainage channel/river course. Clearly a major undertaking to save water as the climate dried. This region has numerous dry river courses, easily seen on satellite imagery. I have always been disappointed by the lack of good research on this culture, away from the well-known city sites.

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