Did Climate Change Kill the Mayans?

A familiar modern problem may have wiped out a grand ancient culture

  • Share
  • Read Later
Douglas Kennett, Penn State

The interior of Yok Balum cave in Belize, where scientists harvested a telltale stalagmite

There are a lot of things that didn’t kill the Mayans: asteroid strikes, planet-wide quakes, global cataclysms prophesied by  shamans and etched into ancient calendars. What did wipe them out was likely something that is far less mystical, and indeed is entirely familiar to modern civilizations: climate change. If you want a look at what we could face in the decades and  centuries ahead, look at what one of the world’s greatest cultures suffered a millennium ago. That’s the conclusion of a  newly released study and what it lacks in Hollywood-friendly drama, it makes up in sound — and scary — science.

The arc of the Mayan rise and fall is well known: The civilization first took hold in 1,800 BC, in the Central American region that now includes and surrounds Guatemala. It grew slowly until about 250 A.D. At that point, a great expansion of the culture — known to archaeologists as the Classic Period —  began and continued to 900 A.D., yielding the architectural, political and textual artifacts that have so mesmerized scientists. But a decline began around 800 A.D. and led to a final collapse about 300 years later.

The Mayan arc was  hardly smooth and steady, and there were periods of turbulence and decline even during the golden era. The great settlement of El Mirador, which once might have been home to 100,000 people, collapsed around 300 A.D, for example. From the fifth to eighth centuries A.D., there was an explosion of the rich tablet texts that provided so many insights into how the Mayans lived and worked. Suddenly, however,  starting in 775 A.D., the number of texts began to plunge by as much as 50%, a bellwether of a culture that was declining too.

(More: How the Drought of 2012 Will Make Your Food More Expensive)

There have been a lot of theories for what accounted for such cycles, with climate among the most-mentioned. The better the year-to-year weather — with plenty of rainfall and reasonably steady and predictable temperatures — the better crops do, and the more the culture and economy can expand. The texts have hinted at declines in productivity, perhaps climate-related, coinciding with generations of unrest, but there was never a precise way to confirm those writings. Analysis of lake sediments can yield a reliable reading of the levels of sulfur, oxygen isotopes and other atmospheric markers at various points in history, which reveal a lot about rainfall and other critical variables. But the Mayans themselves often unwittingly disturbed those sediments, with deforestation — including wide-scale burnings — and fishing.

Anthropologist Douglas Kennett of Penn State University, leader of an international team of researchers from the U.S., Belize, Switzerland, Germany and elsewhere thus decided to look at another, less vulnerable, source of evidence: stalagmites in caves. Some of the rainfall absorbed by the ground over the course of centuries will seep into caves and be incorporated into the drip-drip-drip of wet limestone that causes stalagmites to form. Oxygen isotopes entrained in the rain can provide an indicator of how wet a region was at any one point in history.

As Kennett and his colleagues reported in the current issue of Science, they focused their investigation on a cave in the jungles of Belize, which is within 1.5 km (.9 mi.) of one significant Mayan site and 19 mi. (30 km) of three others. In 2006, the scientists harvested a 22-in. (56-cm) stalagmite from deep within the cave. Knowing the rate at which stalagmites develop, they could calculate that the top 16.3 in. (415 mm) of it had been growing continuously since 40 B.C. Every 0.1 millimeter — or about four one-thousandths of an inch — corresponded to about 0.5 years. That’s an awfully fine-grained way to look at history, and the analysis led to some awfully detailed conclusions.

(More: Why the Drought Won’t Be Getting Better Anytime Soon — And Why This One Won’t Be the Last)

Droughts lasting at least a few decades each occurred from 200 to 1100 AD, and repeatedly coincided with struggles and upheaval in the Mayan culture. There were dry periods in the 640 to 660 window, for example, and there was also a lot of warfare in that period, which makes sense for a culture fighting over dwindling resources. Droughts from 820 to 870 similarly were associated with an outbreak of fighting, as well as the disintegration of local polities, or ruling bodies. The decline in historical texts began not long before another period of severe drying, and the collapse of the Mayan culture itself, directly corresponds to the most severe period of drying, from 1020 to 1100.

Broadly, explains Kennett, the most generous period of rainfall during the millennium or so the Mayans thrived was from 450 to 660. “This led to the proliferation of cities like Tikal, Copan and Carasol,” he says. “The new climate data show that this salubrious period was followed by a general drying trend…that triggered a decline in agricultural productivity and contributed to social fragmentation and political collapse.”

(More: When the Rains Stop)

The cause of the climate upheaval that claimed the Mayans was not, of course, human activity, since their culture thrived and died long before the industrial age. Instead it was caused by the combined effects of El Niño events and changes in the northeast and southeast equatorial winds known as the intertropical convergence zone. “The preceding conditions stimulating societal complexity and population expansion helped set the stage for later stress on [Mayan] societies and the fragmentation of political institutions.”

This should not give comfort to the dwindling band of modern-day climate-change deniers likely to take the study as proof that the planet’s current climate woes are merely natural fluctuations. The Mayan drying trend played out over centuries, after all. What we’ve been experiencing is the more abrupt, short time-scale variety, a phenomenon that was first foreseen in climate models nearly 40 years ago, and has been unfolding pretty much on schedule and as predicted. The Mayans had no such power to forecast events and certainly couldn’t correct them. We can do both, and the lesson of the study is that we may pay mightily if we choose to take no action. No culture, as the vanished Mayans so starkly illustrate, is too big to fail.

More: Butterflies Moving North to Escape Climate Change

66 comments
SkipBaltar
SkipBaltar

Those dang Mayans and their SUV's ...........

gracechiou88
gracechiou88

People taking part in the move to reduce greenhouse emissions do not know how well they are doing.  Government agencies only highlight the importance of immediate action but have not yet calculated for example, how much gas emissions can be reduced by unplugging unused electrical cords or walking a two bus-stop distance instead of riding the bus.  If people know about more statistics and can brag about them, this might ecourage more people to participate.

DennaKatarra
DennaKatarra

On my research, I studied where the Mexicans originated.  The Mayans originated from Mexico therefore the Mayans never were actually killed off.

ChrisThomasWakefield
ChrisThomasWakefield

Renaming G.W. Theory to "Climate Change" and "global warming" was a smart move by the big money Internationally-supported westernized government organizations driving the concept. Who renamed it? Operatives within the U.N. scientific management?, the N.O.A.A.? or the W.M.O.? Well, whoever decided on that, must have realized that having "theory" in the name of the broad, internet-driven explanations by government-supported science for the massive earth-changes we are seeing today, gives the movement more authority. Back in the  day, the public was less knowledgeable and more impressionable, since G.W. Theory was just a fledging boondoggle back when the Internet was just starting.Anyone who has really studied this so-called Climate Change against what is really happening to Earth at this time knows that the core assumptions given by G.W. Theory just doesn't fit the pattern. There are many aspects of what we are seeing, for example: dramatically increased volcanic activity, extreme temperature changes the world around, changes in the apparent orbit of the moon, unexplained sky events, such as Norway 2009, massive flooding in Pakistan (2010). The common excuses proffered by the establishment has been refuted by scientists outside of the cabal of certain government-paid climate scientists. Under the control of climate science management, there many well-meaning scientists, I'm sure, but those that have counter theories are side-lined, remember ClimateGate? The original website is down now, of which I was disappointed to find, but not surprized.  The general public today is too busy to research around the cover-up and the lies trotted out about earthchanges, but it's possible. The truth about earth changes is not found in the Six O'clock evening news, however. So the early alarm falls to people who either have the time, the interest and the mental skills to investigate anomalous sky, space and earth events and even seemingly normal world-wide events and combine them into a very large and single coherent pattern.Many people I know just don't want to hear about the evidence that is obvious seen by LASCO on the SOHO satellite, or unexplained objects being sighted near the Sun. These are but a drop in the bucket of evidence when you really start to look, but evidence of what and look where? and why would there be a massive cover-up of the truth about the many types of earth-changes assailing Earth? The Sun causing these effects on Earth? It's ludicrous, if so, this would be found in the history books, taught in science classes for many decades and be found in the geological record, but is isn't. This story is far bigger than many people realize, and when they finally begin to understand, it's bigger than that, that's how big this story is. We discuss and explain what is all about here:

http://www.facebook.com/groups/survivingthepoleshift/

RichardSRussell
RichardSRussell

Hiding silently behind the overt words of this article is the untold story of rampant population growth during the fertile period, leading to way more people than the environment could sustain during the dry spells. While OTHER circumstances faced by the Mayans may not have their parallels in the modern world, overpopulation sure does. And if you want to see the world's primo example of it, check out Saudi Arabia, with its broad-based population pyramid, resting on a foundation of rapidly depleting oil wealth. Unlike the Mayan rains, the oil will not be coming back.

rasbe
rasbe

The Mayans have not been killed. They're still living in Mexico and Guatemala.

GH
GH

The phrase "climate-change deniers" is politically slanted.  Here's why:  Firstly, most of us don't deny, but rather question.  Secondly, most of us believe that the climate is changing, as it has many times throughout the history of the planet, but question how effect human activity has on that change.  So, a writer who wasn't trying to make a political point would use the phrase "anthropogenic climate-change skeptic".  He could replace "anthropogenic" with "human-caused" if he wanted to avoid such a polysyllabic word.

JohnBlackadder
JohnBlackadder

This was a great article right until the last paragraph. The obligatory worship statement for AWG flies in the face of recent analysis by no less than the British Met Office. This says that the warming trend of the 80's was part of a cyclical behaviour and that the last 16 year cycle is flat to cooling.

So much for the worship of AWG!

gen81465
gen81465

Unbelieveable!!!! They're NOT going to blame the Mayan climate change on George W. Bush??????  Do you mean to tell me that climate change might be something NATURAL that happens, on a regular cycle?????  Obviously, someone on the Al Gore payroll slipped off the party-line bandwagon.

JosephLCooke
JosephLCooke

Too many Mayas driving too many Suburbans.

twseal77
twseal77

The thing that always gets me about these types of articles is that they make it sound like they all died or disappeared somehow. Sure, the culture may have gone, but the Maya people still live on... They are called Guatemalans, Mexicans, etc.

rgill333
rgill333

Hey Editor: "Mayan" is the language,  "Maya" are the people, though in common usage people get the terms mixed up all the time. So a more correct title would be "Did Climate Change Kill the Maya"? 

Correct usage: maya civilization, maya culture, maya people do this and that, but they speak and write Mayan.

HenryMiller
HenryMiller

Right there in this bit of propaganda is the statement, "The cause of the climate upheaval that claimed the Mayans was not, of course, human activity..." but just one paragraph later comes "This should not give comfort to the dwindling band of modern-day climate-change deniers..."

Mr Kluger must think we're all idiots.

Time magazine is doing itself a significant disservice by allowing this sort of obviously biased drivel on its web site.  And, yes, it's obviously biased--the use of the deliberately pejorative term "climate-change deniers" makes that plain, as does asserting that the ranks of the skeptics are "dwindling" when in fact the opposite is true.

The time period to which Mr Kluger refers, late in the first millennium, corresponds to what's called the Medieval Warm Period in Europe--an era that saw the end of the so-called "Dark Ages" and prefaced the European cultural boom of the Renaissance.  The very circumstance that Mr Kiluger claims killed the Mayan civilisation was a big part in rescuing Western civilisation from the centuries of shock resulting from the fall of the Roman Empire.  But of this, Mr Kruger says not a word.  Mr Kruger's is a thoroughly one-sided view--propaganda.

And, regarding the Medieval Warm Period, the subsequent era termed the Little Ice Age, not to mention millions of preceding climate swings of ice ages and warm periods, no climate model yet exists that can reliably explain any of it.  If climate so-called "scientists" can't explain the past, how can they possibly claim to be able to predict the future?

yougotproblem
yougotproblem

It has to be God. Nothing can explain it.  Simple and stress free -- God's will.

JuanHerrera
JuanHerrera

"swindling resources"???? Excuse me, but should it not be "dwindling resources"?

bobpitt
bobpitt

Ignorance is not an excuse..

The mayan people they still live in the same areas and they did five hundred years ago..

RScottGrimes
RScottGrimes

So let's, in three of those period there was 160-170 years good weather turned bad. Is it coicidence history is repeating itself? Or a whole bunch of scientists getting research grants and predicting based off computer models they program? The same scientists that were debunked over the Ozone? Back in Middle School in the 70's-80's, it was predicted we were coming out of mini Ice Age, and that was without computers. Those ICe Ages were not that long ago in Europe.I mean the fiords in Norway are from Ice Caps melting, and after refreezing, aret melting again It's natural cycle. We probably effected global warming more by deforestion, damning rivers, beach erosion from building on them, and let's not even get started on how was have asphlted so much of the earths surface, thus heating up cities and effecting airflow off natural patterns. So yeah, we may be affecting it some, but I think we are trying to demonize the wrong sources.

RobDogg22304
RobDogg22304

Screw it. We gotta die of something because nothing last forever. At least they'll be benefits like palm tress in Virginia while we're dying off.

jj
jj

Yes, they lost enough water to support their civilization

RobertCarlson
RobertCarlson

I'll say it again.  It doesn't matter what causes the climate to change, humans, nature or the clockwork of planetary and solar cycles.  what does matter is our response to those changes.  Are we prepared for a decade of drought in the breadbasket of the USA?  Will we build infrastructure capable of providing sufficient fresh water for populations all around the world, or will we sacrifice them with starvation (as opposed to the Mayan blade.?)  Will we develop ways to provide food or die in our ignorance and denial?  Solutions take a long time and we must start sooner rather than later to solve the imminent collapse that will happen if we fail to act.

BillLafayette
BillLafayette

@gen81465 Where did you read anything about decade long droughts as being a regular cycle? And it does indeed seem that you failed to read the last paragraph.

hhbonobo
hhbonobo

@gen81465 Read the last paragraph again. I think you missed something.

robin.carduner
robin.carduner

@HenryMiller That's exactly correct -- the warming period was global, but the collapse of one civilization was broadly coincident with the rise of another.  This does not, however, instantly disprove any kind causal relationship between climate change and human success; in fact, it bolsters the argument for one.  The difference was the pre-existing local climates:  warmer in central and south America, and cooler in Europe; hence a rising global temperature made the former too warm and the latter "just right".  Likewise with any possible current warming trend, there will be winners and losers.  The main worry is that most of the world's population is currently situated in the losing areas; i.e. those that will be too warm and/or under water.

Regarding your assertions about there being "no models" that predict these climate changes, that's not quite correct.  There are in fact, plenty of such models.  The issue is that there are too many variables and factors involved for a strictly computational, single-model approach to the problem, and thus successful "prediction" as might be commonly understood will in fact *never* be possible.  So we have to break the issue down into more digestible pieces, smaller, incomplete models.  Over time, we compare different models to determine which factors are more relevant and which ones less so, which models are more accurate.  That's *really* what climate science is.  You're right, scientists can't predict the future with 100% accuracy.  But that doesn't mean that such predictions are 100% wrong or that the whole effort to understand the climate is futile.

About the East Anglia thing:  you may want to follow up on that one since the original story broke.  It is true that there were some comments in leaked e-mails that seemed to suggest the UEA scientists were deliberately trying to mislead the public, but the comments were taken out of context, and after reviewing the larger body of e-mails as well as other evidence, it was concluded by independent investigators that there was no intent to deceive.  While it is true that sometimes people on both of the supposed "sides" of the argument have selected different time periods or averaging methods to bolster their preconceived notions, this was not found to be the case with the UEA scientists.  Mark Twain's quip about "lies, damned lies, and statistics" notwithstanding, just because statistics are applied to a problem doesn't necessarily mean that a lie is being put forth.  Separating signal from noise can be quite a tricky mathematical problem (again because of all those factors), and it's often necessary to take a statistical approach.

I do agree that the author of this particular article does sound a little biased, in the sense that he has been convinced by the argument and is trying to convince others.  But, you seem to be at least as biased in your own way, and judging from the tone of your writing, a lot angrier.  You believe the phrase "climate-change denier" is perjorative, but if you would prefer to consider yourself a "skeptic" instead then you first be willing to accept that you might have to change your mind at some point.  For an idea of the difference between a denier and a skeptic, you could read the story of a someone who looked at the evidence himself and did exactly that.

http://www.nytimes.com/2012/07/30/opinion/the-conversion-of-a-climate-change-skeptic.html?_r=1&pagewanted=all

suchislife
suchislife

@HenryMiller the true voice of a climate-change denier, desperately hanging on to the last semblance of his kind as they dwindle...

mtngoatjoe
mtngoatjoe

@HenryMiller Denying climate change is like insetting woman can get pregnant by sitting on a toilet seat. Giving equal weight to climate change deniers insults the years of painstaking and overwhelming evidence that has been collected.

JuanHerrera
JuanHerrera

@HenryMiller Well Henry, what is your take on the effect of the rise of greenhouse gases? The volume of fossil fuel consumption is much higher, the population of the world is much more than the periods you mention and the industrial revolution had not yet begun.

BillLafayette
BillLafayette

@JuanHerrera The dwindling undoubtedly led to some swindling. Then the swindling led to the infighting and wars.

JuanHerrera
JuanHerrera

@bobpitt  Well Bob, when the conquistadores arrived, their cities were already in ruins and the people had scattered into the jungles. Their descendants still occupy their ancestral lands in Mexico, Guatemala and other parts in central America.

dfwenigma
dfwenigma

@RScottGrimes Tell ya what Mr. Grimes - develop a journal article - with sufficient refutation, sources, have it pass a committee of your peers and then we'll review it - until then your assertions are specious at best - opinion but worse than opinion because you're attempting to put forth some kind of theoretical construct with very little evidence. Very dangerous indeed.

HenryMiller
HenryMiller

@RobertCarlson 

We've already had a prolonged drought in the "breadbasket"--the "Dust Bowl" era of the 1930s.  <i>Mirabile visu,</i> we got over it.

And who's this "we" who are supposed to go bankrupt building "infrastructure" for a world that, in varying degrees, hates us for little more than being a nation powerful enough to dispense such favours?  We're not the world's nanny--if other countries have climate problems, it's their responsibility to solve them, not ours.

HenryMiller
HenryMiller

@robin.carduner @HenryMiller  

I'd pounded in a fairly lengthy response to your comments, but the page refreshed and it all vanished.

In brief,  it's just about certain that climate is mathematically chaotic, hence the impossibility of accurate modelling.  In the absence of any decent probability of accurate short or medium term model predictions, I think it unwise to commit significant resources to addressing circumstances the effects of which are only basically guessing at, especially since we've no good idea concerning how to to effectively address the circumstances.  Many of the proposals of the climate change proponents would be hugely expensive in both monetary and lifestyle terms and it's not at all unreasonable to insist that there be a high degree of certainty that the benefits of the proposals exceed the costs.

And, no, I'm not angry.  But I'm quite adamant that before I would subject the people of this planet, and the people of the US in particular, to the economic and social upheavals concomitant with some of the climate change proposals, I want see very strong evidence of its necessity.  At the current state of climate science, I'm not seeing sufficient evidence.  What I /am/ seeing is an almost religious approach to the subject wherein dissent is treated as heresy and that tends to make me distrust the impartiality of climate scientists.  It looks to me like they're trying to find evidence to prove a conclusion they've already come to rather than trying to fit their conclusions to their observations.

RandyClarke
RandyClarke

Great response.  I was going to say the same thing :)   Seriously, thanks for your comments and especially about HenryMiller seeming angry.  Why is it that those that are skeptic and/or deny climate change seem so angry?  Do they think we are trying to take something from them or is it that there are just those that cannot accept change?

HenryMiller
HenryMiller

@mtngoatjoe @HenryMiller 

 But what about years of cooking the data, as they did at East Anglia?

Collecting the data isn't the issue, it's what data they collect and use of it they make.  For many years, the climate change fanatics have been selectively collecting data that reinforces their preconceptions and trying to suppress data that contradicts them.  And then, of the data that passes their acceptability test, they ignore and try to suppress any explanations other than the conclusions they want to reach.   This isn't science, it's politics.

HenryMiller
HenryMiller

@JuanHerrera @HenryMiller 

I don't have any idea concerning the effect of any increase of greenhouse gasses, nor even whether there's been any such increase.  But it's not up to me to disprove AGW or any other form of climate change, it's up to those putting forth those assertions to prove them.  Thus far, there's been no proof, no models that retroactively predict known climate events--like the MWP, LIA, the Younger Dryas, and so on--based on data from prior to the events.

Science is a process of tailoring conclusions to fit the observations; climate "science" is trying to do the reverse: finding observations that reinforce desired conclusions.

dfwenigma
dfwenigma

@JuanHerrera @bobpitt Let's be plane the Mayan civilization is gone. The people who live in Mexico and Guatemala may have a physical link to the Mayans but they're no more Mayan than some of the white people who claim they are related to Matoaka

RobertCarlson
RobertCarlson

@HenryMiller @RobertCarlson Went I say "we" I don't mean Them and Us (not US either).  It is all of the cultures on this planet that are interdependent on the same air to breathe, water to drink and food to eat.  For example, I live in a city that will be one of the last to lose water.  Other cities like Phoenix and LA depend on the water "rights" assigned long ago before there was a large shortage looming.  THEY will be the ones to be without unless infrastructure is built.  With the amount of groundwater contamination being perpetrated on well water users, they too will need the water.

Yes, we had the dust bowl years but we had half the population too.  Americans freak when the price of bread rises 50 Cents.  Imagine 307 million people freaking when the crops fail like they did in 2012 and it goes on for a decade.  Let's hope that doesn't happen, but if it does, we need to be responsive or we will look like a Darfur Refugee Camp.

Nanny's are overly criticized and under appreciated.  We all need a Nanny State sometimes.  Gov. Christie discovered that last week along with 8 million other of us.

JuanHerrera
JuanHerrera

@HenryMiller @RobertCarlson "-if other countries have climate problems, it's their responsibility to solve them not ours" What??? By your statement, I guess those "other" countries are on a separate planet. Deforestation of the Amazon affects us, coal burning by China affects us, so??

RandyClarke
RandyClarke

Sounds just like you.  You are just arguing the opposite.

HenryMiller
HenryMiller

@GH @hhbonobo @HenryMiller  

 "Self-interest" is the key phrase here.  When people see their lives being adversely affected by any climate change that may occur, they'll act in such a way as to minimise the adverse effects.  But until people see for themselves the adverse effects, trying to force them to do various things and pay various taxes to avert effects that may or may not occur is simple tyranny.

And I agree--I switched to CFLs years ago.  Just yesterday I topped-off the refrigerant in one of my home air-conditioning with something called EF-22a, a non-fluorocarbon  replacement for freon, and so on.  It doesn't hurt to do these things, and it saves me money, and it's <i>my</i> choice to do them.

N.B.  if you fiddle with your own AC refrigerant, be careful--I accidentally squirted a bit on a finger, resulting in spots of <i>severe<i> frostbite and blisters that look like I'd sprayed my hand with molten lead.  Not fun.

GH
GH

@hhbonobo @HenryMiller   It DOES hurt.  It will be a drag on our economy, causing more unemployment and more poverty and reducing tax revenues that the government needs.  When alternatives make economic sense they will come into use.  I'm skeptical of AGW but have still improved my insulation and bought CFL and LED bulbs and an efficient car, in my own self-interest.

HenryMiller
HenryMiller

@hhbonobo @HenryMiller 

 The biggest question is what you mean by "use fewer resources."  And whether that implies the heavy hand of government to enforce it.   The current Secretary of Energy has said he'd like to see $8.00/gallon gasoline in an effort to force people to use less gas.  That would /definitely/ hurt, as would "cap and trade," which would raise energy prices enormously.

Nothing wrong with recycling, etc., but you have figure in the costs, both in terms of money and in terms of diminution of lifestyle, for any action.

hhbonobo
hhbonobo

@HenryMiller Well, then would you agree that it doesn't hurt to, say, not pollute, recycle, use fewer resources, etc. Why do you need proof to be a responsible citizen? And if you think it a ploy that humans are influencing the climate, then ignore it. It shouldn't change your approach to the planet. 

RobertCarlson
RobertCarlson

@JuanHerrera @HenryMiller @RobertCarlson The US has 6% of the world population and consumes 25% on its resources (in particular fossil fuels) and is driving everyone elses need to respond to climate change.  The biggest three contributors to CO2 production failed to sign on to the Kyoto Treaty.  Go figure.