More Tabloid Climatology – now ‘extreme weather’ killed the Mayans

From the University of California – Davis  and the “seek and ye shall find” department, a stunning example of Tabloid Climatology™ trying to link “extreme weather” with the Mayan civilization collapse. They did get one thing right though with this quote:

“We are dependent on climatological events that are beyond our control.”

As usual with bad press releases like this, they don’t name the paper, just the claims and the silly headline. (See update below for the paper) It is funny how a naturally occurring drought gets morphed into the “extreme weather” meme of the current news cycle.

Extreme weather preceded collapse of Maya civilization

Decades of extreme weather crippled, and ultimately decimated, first the political culture and later the human population of the ancient Maya, according to a new study by an interdisciplinary team of researchers that includes two University of California, Davis, scientists. 

The collapse of the Maya is one of the world’s most enduring mysteries. Now, for the first time, researchers have combined a precise climatic record of the Maya environment with a precise record of Maya political history to provide a better understanding of the role weather had in the civilization’s downfall.

Their findings are published in the Nov. 9, 2012 issue of the journal Science.

“Here you had an amazing state-level society that had created calendars, magnificent architecture, works of art, and was engaged in trade throughout Central America,” said UC Davis anthropology professor and co-author Bruce Winterhalder. “They were incredible craftspersons, proficient in agriculture, statesmanship and warfare—and within about 80 years, it fell completely apart.”

To determine what was happening in the sociopolitical realm during each of those years, the study tapped the extensive Maya Hieroglyphic Database Project, run by UC Davis Native American Language Center director and linguist Martha Macri, a specialist in Mayan hieroglyphs who has been tracking the culture’s stone monuments for nearly 30 years.

“Every one of these Maya monuments is political history,” said Macri.

Inscribed on each monument is the date it was erected and dates of significant events, such as a ruler’s birthday or accession to power, as well as dates of some deaths, burials and major battles. The researchers noted that the number of monuments carved decreased in the years leading to the collapse.

But the monuments made no mention of ecological events, such as storms, drought or references to crop successes or failures.

For that information, the research team collected a stalagmite from a cave in Belize, less than 1 mile from the Maya site of Uxbenka and about 18 miles from three other important centers. Using oxygen isotope dating in 0.1 millimeter increments along the length of the stalagmite, the scientists uncovered a physical record of rainfall over the past 2,000 years.

Combined, the stalagmite and hieroglyphs allowed the researchers to link precipitation to politics. Periods of high and increasing rainfall coincided with a rise in population and political centers between 300 and 660 AD. A climate reversal and drying trend between 660 and 1000 AD triggered political competition, increased warfare, overall sociopolitical instability, and finally, political collapse. This was followed by an extended drought between 1020 and 1100 AD that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya population.

“It has long been suspected that weather events can cause a lot of political unrest and subject societies to disease and invasion,” Macri said. “But now it’s clear. There is physical evidence that correlates right along with it. We are dependent on climatological events that are beyond our control.”

Said Winterhalder: “It’s a cautionary tale about how fragile our political structure might be. Are we in danger the same way the Classic Maya were in danger? I don’t know. But I suspect that just before their rapid descent and disappearance, Maya political elites were quite confident about their achievements.”

###

Co-authors leading the study are Douglas Kennett of Pennsylvania State University and Sebastian Breitenbach of Eidgenossische Technische Hochschule in Switzerland. The research was funded by the National Science Foundation, the European Research Council and Alphawood Foundation.

UPDATE: Abstract and link to paper here

http://www.sciencemag.org/content/338/6108/788

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84 Responses to More Tabloid Climatology – now ‘extreme weather’ killed the Mayans

  1. Richdo says:

    Extreme weather preceded collapse of Maya civilization

    Ok, so we can exclude hunan sacrafice as means to combate “climate change”. Wonder if the CAGW zealots will take note of this? My guess is: “No, get the deniers of science!”

  2. Tim Ball says:

    There is nothing new in this research – the drought that brought about the demise of the Maya has been in the climate literature for years.

    Besides how could they deduce drought from stalactites (memory help “c” is for ceiling) and stalagmites (“g” is for ground) – weren’t they used to determine temperature in the 2007 IPCC attempt to salvage the hockey stick?

  3. Andrés says:

    But, according to The Mann there was no warming then!
    So, maybe CAGW = Catastrophic Climate Change breaks down from time to time?

  4. Zeke says:

    That is one idea.

    Another idea is that an elite priesthood and aristocratic class developed, who made a living by telling people what they could and could not eat, and passing laws about what “stuff” they could have, contrary to their original myths and legends, in which a loving God sent his Super Twins to give the gifts of fire, cotton, crops, cattle, water, and just laws, to all people.

  5. Andrew30 says:

    Anthony;
    Perhaps there may be something to this. What if Mayans has an active warmist movement that was scared by natural phenomena and the warmist convinced the leaders to prevent the use of natural resources to support the population.
    That could wipe out a civilization.

    Think of Sandy and the recent election:
    Extreme weather preceded collapse of American civilization

    History may repeat itself.

  6. What Did I Tell You!? says:

    Magic Melting Mauled Mayan MesoaMerican Metropolitan Members’ Making Money Mechanisms.

    Whereas mountainous jungle civil war involving human hearts being cut out and human flesh being consumed in front of said humans’ closest relatives,

    didn’t faze em…

    the outbreak of more, or less rain, ruined their whole civilization. Yah..YEAH!

    Surrounded by local climate buffered by oceans large and warm, on from two, to three sides, while engaging in farming, animal husbandry, FISHING, MINING, and other environmentally intensive activities,

    the temperatures rising or falling a few degrees
    made everybody go insane.
    It was bad weather made war break out.
    Yeah, THAT’s thuh TICKeT!

  7. TomC says:

    So the climate has been slowly changing throughout the course of the Holocene – got it.

  8. Louis says:

    ‘Ok, so we can exclude hunan sacrafice as means to combate “climate change”.’
    =====
    Oh good, the Chinese can breath easier now.

  9. Amr Marzouk says:

    Human sacrifice and flush toilets don’t mix

  10. Larry Ledwick (hotrod) says:

    As above no new info, there is a TV special on the topic I have seen several times.

    http://www.bbc.co.uk/history/ancient/cultures/maya_01.shtml

    Just regurgitation of Dick Gill’s research it looks like to me.

    Larry

  11. Ian L. McQueen says:

    Aide memoire…..

    The mites go up and the tites go down.

    IanM

  12. beesaman says:

    Those Mayans and their gas guzzling V8s!
    Serves them right…

  13. Louis says:

    “Decades of extreme weather crippled, and ultimately decimated, first the political culture and later the human population of the ancient Maya, according to a new study…”
    =====

    What? There was “extreme weather” before modern times? I thought all extreme weather was “unprecedented” and due to our modern addiction to fossil fuels. Who knew there could be other causes?

    Are Warmists now going to point to the end of the Mayan calendar as proof that the world is coming to an end due to climate change if we don’t act now?

  14. R. Shearer says:

    Plus they invented Planned Parenthood.

  15. omnologos says:

    The Mayan Hockey Stick predicted 6C of increase in world temperature by December 2012…

  16. Juan Slayton says:

    Tim Ball: …stalactites (memory help “c” is for ceiling) and stalagmites (“g” is for ground)

    Need more help? It’s like ants in the pants–the mites go up and the tites go down.
    : > )

  17. winston101 says:

    The lesson to be learned here is that when an advanced civilisation falls, for whatever reason, it does so in a very rapid spiral which unleashes in a relatively short period of time. A preview of coming attractions.

    The paper also validates the MWP as a global “warming” event, which being free from anthropogenic influences could not have been “avoided” by any Mayan Carbon Reduction Schemes, Renewable energy scams, or other Mayan bureaucratic interventions. No human intervention or sacrifice to their Gaia equivalent could save them, just as our symbolic and Quixotic attempts to follow suit are similarly pointless and counter-productive. As their civilisation crumbled- increasing sacrifices of their human capital to appease the Gods only hastened their demise. There but for the grace of God go us all. The parallels to the current situation are remarkable, and disquieting to say the least.

  18. Jimbo says:

    When did weather become the climate? First we have:

    Extreme weather preceded collapse of Maya civilization

    Then we have:

    This was followed by an extended drought between 1020 and 1100 AD that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya population.

    “It has long been suspected that weather events can cause a lot of political unrest and subject societies to disease and invasion,” Macri said…………

    The IPCC and the WMO say climate is 30 years or more of data yet these alleged researchers have decided that 80 years of climate is the weather. Which is it? The climate or the weather?

  19. polistra says:

    Every empire weakens and fades sooner or later. It’s the nature of the beast. While a culture is strong, it’s able to get through bad years by storage and engineering. After it starts to weaken, it neglects grain storage, replaces builders with lawyers or priests, and allows its dams and irrigation systems to decay. As we’re doing now.

  20. Jimbo says:

    Is it any wonder how “Extreme weather” existed at a time of such low atmospheric co2. If exactly the same drought happened in exactly the same place today you know what to blame: co2.

    Below are a few acknowledgments and examples of low Co2 ‘induced’ abrupt climate changes. ;) NB they sometimes speculate about the future of man’s increased co2 using models.

    http://tinyurl.com/c5swtzh

    http://www.sciencemag.org/content/299/5615/2005.short

    http://www.jstor.org/discover/10.2307/30081147?uid=3738096&uid=2&uid=4&sid=21101351963891

    http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291099-1417%28199611/12%2911:6%3C451::AID-JQS275%3E3.0.CO;2-9/abstract

    http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=13760252&q=&uid=791805140&setcookie=yes

  21. Steve from Rockwood says:

    People look to climate as the cause but it could just as easily be human-caused. Too many people moving into one place, displacing food production further from the center. Eventually the city grows too large to sustain itself (no change in climate or rainfall). There were also pre-Mayan civilizations that collapsed, one near Pachuka that saw pyramids built before Christ was born.

  22. son of mulder says:

    They were extremely concerned about over population so they decided to starve themselves to death to save future generations ;>)

  23. One of the things that the Mayan’s also had was a command economy. There was no such thing as private enterprise – which meant that they didn’t have much flexibility built into their system.

  24. Ben D. says:

    Btw, the ancient Mayans (along with other native Americans) are descendants of the Lamanite and Nephite races of the Book of Mormon, perhaps the conjectured disaster prophecy connected with the ending of the Mayan calendar in December 2012 shows prescient judgement for the rejection of Mitt Romney in the presidential erection, :).

  25. Jimbo says:

    Tim Ball says:
    November 8, 2012 at 2:37 pm

    There is nothing new in this research – the drought that brought about the demise of the Maya has been in the climate literature for years.

    You are correct! Why are these people being funded to tell us what’s already out their? Is it because in their grant proposal they mention “Extreme weather”? I doubt it. ;)

    http://scholar.google.com/scholar?q=Maya+civilization+drought&btnG=&hl=en&as_sdt=0%2C5&as_vis=1

  26. Richdo says:

    Rhoda Ramirez says: November 8, 2012 at 3:42 pm
    One of the things that the Mayan’s also had was a command economy.

    +1
    Good point!

  27. Terry says:

    “Now, for the first time, researchers have combined a precise climatic record of the Maya environment with a precise record of Maya political history to provide a better understanding of the role weather had in the civilization’s downfall.”

    A “precise record” ……Really..You have to wonder if there is any pre-exisitng bias when you read words like that. Just sayin’

  28. D Caldwell says:

    Not sure exactly what point the authors wanted to convey, but the idea that large and abrupt changes in climate occurred prior to increases in CO2 comes through loud & clear.

  29. GeoLurking says:

    “… that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya…”

    So… something happened that made their way of life, their means of supporting themselves, non-productive or highly inefficient. and their society broke down.

    What does that say about mandating higher (fuel/energy) prices for manufacturing or transporting goods? That’s a whack on the efficiency side of things. Mandating/subsidizing less efficient land usage (alcohol vs food) doesn’t seem to go very far in the common sense department either.

    Yep… you can learn a lot from the Maya.

  30. D.I. says:

    How much did this Toilet paper cost? Look at all the so called ‘Scientific Papers’ and ask yourself, was this value for money?
    Maybe a site like this should have a two box system of ‘Science Fiction’ and ‘Science Fact’ and let the ‘Expert’ readers decide where to dump them.
    P.S.
    Just a thought from a layman In a drunken state(ment).

  31. jabre says:

    “For that information, the research team collected a stalagmite from a cave in Belize, less than 1 mile from the Maya site of Uxbenka”

    Data from *one* cave? Any chance that some recharge water could have been redirected to the nearby populated area or crops over that time period? Any chance at all? Perhaps, before trumpeting this supposedly new information they could at least use some confirmation data from another site.

  32. Luther Wu says:

    in addition to relieving the lower classes of enough heads to appease The Snake gods, the Mayan elite also taxed the peasants.

    Now, the elites have the tax part down, let’s hope they don’t get any ideas about heads.

  33. markx says:

    Altogether a pretty shocking realization:

    Climate can change.

  34. David Larsen says:

    Actually, if I remember correctly, Michael Harner wrote an analysis about the Aztecs. The concept was they exceeded their ‘carrying capacity’ (too many people locally and not enough food) so they started sacrificing members of the group and threw their bodies in large kettles and meat for dinner. Flesh, it’s what’s for dinner. Cahokia also exceeded their carrying capacity and they just split.

  35. So they can cut a stalagmite in small sections and say what the weather was like several hundred years ago? They can then deduce from hieroglyphs the fate of a civilisation, by linking in these weather events?
    B******s! They would have pre-determined the results and made certain that their archaeological vandalism fitted in with their “research”.
    The next unanswered question is; do they want more funding to research the demise of other civilisations by lopping of bits of other ancient rocks in exotic parts of the world. Mauritius andSri Lanka sound like two good places to start, they would need Business Class tickets, 5 star hotel accommodation, food and booze allowance and a hacksaw!

  36. Gary Pearse says:

    So extreme weather has been ramping up since. Well we’ve, at long last, got hurricanes in hand with the new paleotemptressology fresh off the GSA press. Now lets see, paleodryupandblowawayognomy should be inaugurated – maybe at the 2013 meeting.

  37. Mike Bromley the Canucklehead says:

    “It’s a cautionary tale about how fragile our political structure might be.” What an ominous statement, so soon after a divisive election!

    “But the monuments made no mention of ecological events” That’s because David Suzuki’s ancestors hadn’t invented the Anthropocene yet. I mean come ON, you guys, pass the ganja….or was it peyote?

    D Caldwell says:
    November 8, 2012 at 4:02 pm:

    Of all the points that climate science makes, over and over, is their ineptitude at disguising natural climate cycles….or, the pretence that for some reason natural climate change stopped in 1950. But be careful, D Caldwell, they will find a source for that blessed gas in some hieroglyph.

  38. Transport by Zeppelin says:

    >>> Tim Ball says:

    November 8, 2012 at 2:37 pm
    “There is nothing new in this research – the drought that brought about the demise of the Maya has been in the climate literature for years.” <<<

    +1

  39. davidmhoffer says:

    Tim Ball, Jimbo, Transport,

    Yup, I attended a lecture on the fall of the Mayan’s being due to climate change at LEAST 15 years ago and perhaps more (the decades start to blur together as one ages).

    Re their calendar – odd that some people want to believe that the Mayan’s predicted something bad was going to happen in 2012. You’d think that if they were any good at predicting anything they would have predicted their own demise….

  40. Karl W. Braun says:

    As far as I know the Maya are still around.

  41. Brian H says:

    Nothing new? It’s now officially PRECISE, carved in (lime)stone.

  42. dmacleo says:

    D Caldwell says:
    November 8, 2012 at 4:02 pm

    Not sure exactly what point the authors wanted to convey, but the idea that large and abrupt changes in climate occurred prior to increases in CO2 comes through loud & clear.
    *****************

    thats what I thought too, but I am probably the least versed person here so did not want to ask.

  43. Skunkpew says:

    I think they have to get away from the idea that the collapse of the Maya is an ‘enduring mystery’ that took less than 80 years. There never was a sudden collapse as they want to envision it, it was a 400 year process of societal change. The northern Yucatan sites were gaining power over those in the southern rainforests because of better location and access to food. Add in a culture of constant warfare, and the oldest southern sites became obsolete and abandoned.

    In addition, the populations at the traditional southern sites, like Copan and Tikal, drastically exceeded the carrying capacity, and people naturally spread out to new sites in order to survive. But this started happening as early as 800 AD. This decreased the prestige of those old centers and further undermined the importance of that entire southern area as the core of the Mayan society. The northern sites began to eclipse the southern sites as places of ritual and worship. The northern Maya civilization still existed when the Spanish arrived by 1500 AD, albeit only with about a population of 800,000 compared to the 3 million of Classic Maya civilization in 800 AD. Over 700 years, that is not even that perceptible.

    Plus I’ll take over 30 years of pollen and vegetation sampling from distingushed archaeologists on location at these Mayan sites–who state that the climate remained basically stable over this time–to the single report that seeks to connect the fall of Maya society to the fall of our own society.

  44. Gail Combs says:

    Good grief, I hope none of those tabloid types get a hold of ChiefIO’s Bond Event series! link and especially his Of Time and Temperatures

  45. Gail Combs says:

    polistra says:
    November 8, 2012 at 3:26 pm

    Every empire weakens and fades sooner or later…..
    _______________________________
    If I recall correctly it takes around 200 years or so.

    …Alexander Fraser Tytler, a European historian published The Decline and Fall of the Athenian Republic. In his publication, Tytler reported that from his research he had determined the following:

    “A democracy cannot exist as a permanent form of government. It can only exist until the voters discover they can vote themselves largesse from the public treasury. From that moment on, the majority always votes for the candidates promising them the most benefits from the public treasury, with the result that a democracy always collapses over a loss of fiscal responsibility, always followed by a dictatorship. The average of the world’s great civilizations before they decline has been 200 years. These nations have progressed in this sequence:

    From bondage to spiritual faith,
    From spiritual faith to great courage,
    From courage to liberty,
    From liberty to abundance,
    From abundance to selfishness,
    From selfishness to complacency,
    From complacency to apathy,
    From apathy to dependency,
    From dependency back again to bondage.”

    If Tytler’s conclusion is correct, this year America exceeded the average length for a democratic form of government by 33 years…. [as of 2009]
    Source

  46. Goode 'nuff says:

    There are some Maya around, but they live in mainland Mexico and were a separate tribe from the ones on the Yucatan Peninsula. Deforestation likely didn’t help…

    http://science.nasa.gov/science-news/science-at-nasa/2009/06oct_maya/

  47. Gail Combs says:

    jabre says:
    November 8, 2012 at 4:25 pm

    “For that information, the research team collected a stalagmite from a cave in Belize, less than 1 mile from the Maya site of Uxbenka”

    Data from *one* cave? Any chance that some recharge water could have been redirected to the nearby populated area or crops over that time period? ….
    ________________________________
    Good point. All it would take is a minor earthquake tumbling rocks into the watercourse and altering the path.

    Description of the area: http://www.southernbelize.com/uxbenka.html
    (It is located in southern Belize)
    Description of the Seismic Activity in Belize

    ….For Belize, earthquake hazard increases steadily from the north of the country to the south as can be observed in the Maximum Seismic Intensity in Belize (See Figure 8.4). Earthquakes that affect the country of Belize occur in the Gulf of Honduras which is the plate boundary zone between North America and the Caribbean. Belize, on occasion would experience mild tremors as a result. The US Geological Survey’s National Earthquake Information Center (NEIC) is responsible for the tracking of all these epicenters and according to the NEIC, Belize would experience a 6.0 magnitude on the Richter scale subterranean earthquake in the ocean approximately every 8 years in the fault located between Hunting Caye and Puerto Cortez.

    http://www.doe.gov.bz/documents/EIA/US%20Capital%20EIA/Chapter_8%20-%20GEOLOGY%20AND%20SOILS.pdf

  48. DesertYote says:

    Socialism destroyed the Mayan civilization just like socialism is now destroying western civilization.

  49. Kim Moore says:

    Skunkpew– you’ve written a nice accurate historical description that lacks the drama of this latest “solution to the Mayan mystery.” :)
    In the article much is made of Mayan acccomplishements:

    ““Here you had an amazing state-level society that had created calendars, magnificent architecture, works of art, and was engaged in trade throughout Central America,” said UC Davis anthropology professor and co-author Bruce Winterhalder. “They were incredible craftspersons, proficient in agriculture, statesmanship and warfare—and within about 80 years, it fell completely apart.”

    For all their impressive art and architecture, the Mayans’ “proficiency in agriculture” involved slash and burn methods accompanied by that high tech tool, the fire-hardened wooden digging stick. They hadn’t quite mastered the art of sustained agriculture. Large sections of the Yucatan Peninsula show evidence of soil that had been overused.

  50. Bad weather and catastrophic sea level rise is definitely what killed the Egyptians chasing after Moses.

  51. Chuck Nolan says:

    What Did I Tell You!? says:
    November 8, 2012 at 2:53 pm
    ……the temperatures rising or falling a few degrees
    made everybody go insane.
    It was bad weather made war break out.
    Yeah, THAT’s thuh TICKeT!
    —————————–
    And my wife Morgan Fairchild, whom I’ve seen naked was in charge of the virgin sacrifices.
    Yeah, THAT’s thuh TICKeT!
    cn

  52. AndyG55 says:

    but, but… extreme weather can only happen when the CO2 level is over 350ppm. That’s right, isn’t it ???

    They MUST prove that at the end of the Mayan empire there was over 350ppm atmospheric CO2.

  53. Christopher Hanley says:

    ” … Periods of high and increasing rainfall coincided with a rise in population and political centers between 300 and 660 AD … followed by an extended drought between 1020 and 1100 AD that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya population … ”
    ===================================
    Paradoxically the periods above roughly coincide with the opposite climate-driven effects in Europe, the (cold) Migration Period in Europe (c. 400 – c.800 AD) and the Medieval Warm Period (c. 950 – c. 1250 AD): http://wattsupwiththat.files.wordpress.com/2012/10/esper_2012_fig4.png

  54. Colonel Panic says:

    /sarc on:
    I don’t think it was the weather which crippled the Mayan civilisation. I think it was their ruling elite. The priests (who could foretell the future by the way), grew ever more enamoured of their own self importance and imposed heavier burdens on the populace in terms of taxation and human sacrifice. The plebs simply got jack of it and those that didn’t stick around to end up on he chopping block simply drifted away to more tax/sacrifice-friendly havens.

    Be thankful Western governments only have their hands in your pocket and not in your thoracic cavity. /sarc off:

  55. Rob says:

    Who would publish this garbage?

  56. sophocles says:

    Well, that makes some sense: the drought(s) occurred at about the same
    time as the Northern Hemisphere was suffering its Dark Ages which, while
    not quite as bad as the Little Ice Age, were still unpleasant.

    Dr Michael Hudson had a bit to say about that failure too: when a state’s
    agriculture breaks down, the food supply stops. When it stops, people go
    hungry. Hungry people either riot (see North Africa earlier this year) or walk
    away into the jungle, which the Maya did. Hudson pointed at salted fields,
    which also happened in Mesopotamia over a couple of thousand years ago.

    Irrigatiing with river water without removing the salt is problematic. River
    water is brackish—from the salt washed out of the country-side it’s flowing
    through, which ends up in the ocean. During a long drought, their fields
    would have been irrigated by more and more brackish river water. The
    salt applied to the land won’t be dissolved and washed away by (salt-free)
    rain water. After sufficient time, or rather, after sufficient river water, the
    land loses its ability to crop—from the salt.

    The Murray River valley has this problem. The locals there talk about the
    “salt table rising.” It probably isn’t: the irrigation from the river is applying
    it directly and the land is becoming saltier.

  57. Matt says:

    This is not news as such. This fact (?) has long been presented in TV documentaries on the subject; not based on climate science, but on archeological findings, though. I have seen such a documentary within the past two years (UK TV), but had seen another one already some 15 years ago. The older of the two was interesting in that some guy did a review of historic climate patterns and linked the drought at the Mayans to a 70 year pattern that has a correlating pattern somewhere above Northern Europe / Russia somewhere… but of course I don’t remember the details any more after such a long time. What had been said and shown there were large water reservoirs that indicated that they indeed had to struggle with their water supply.

  58. Sparks says:

    Maybe they just got board!

  59. Sparks says:

    The Mayans didn’t predict anything, that happens thousands and thousands of years later.

  60. Admad says:

    “But the monuments made no mention of ecological events, such as storms, drought or references to crop successes or failures.”
    So it’s all just wild speculation from a political standpoint, as usual.

  61. Ryan says:

    Climate has got a lot more stable since we started pumping CO2 into the atmosphere……

  62. DirkH says:

    Christopher Hanley says:
    November 8, 2012 at 9:51 pm

    “” … Periods of high and increasing rainfall coincided with a rise in population and political centers between 300 and 660 AD … followed by an extended drought between 1020 and 1100 AD that likely corresponded with crop failures, death, famine, migration and, ultimately, the collapse of the Maya population … ”
    ===================================
    Paradoxically the periods above roughly coincide with the opposite climate-driven effects in Europe, the (cold) Migration Period in Europe (c. 400 – c.800 AD) and the Medieval Warm Period (c. 950 – c. 1250 AD):”

    Temperature driven shift in the precipitation patterns / average cloudiness by latitude / Hadley cells?

  63. Tom Davidson says:

    “It’s a cautionary tale about how fragile our political structure might be.”
    Some people see EVERYTHING through a self-centered political lens.

  64. Caleb says:

    RE: polistra says:
    November 8, 2012 at 3:26 pm
    “Every empire weakens and fades sooner or later. It’s the nature of the beast…”

    I agree. However every empire is replaced by different attempts on the part of people to fit their lives into changing circumstances. The Mayans likely went through several ups and downs, booms and busts, times of decay and corruption and times of spiritual revival. The current population is a continuation.

    Just because the current population does not built big structures of stone is no reason to assume it is inferior. For all we know the people may be freer and happier.

    It is actually rare for a people to utterly die out. Usually it involves people living on the edge of habitable lands, such as the Vikings in Greenland or the Anasazi in the desert. Even in their cases, the people may have merely moved on, without leaving a forwarding address.

    When you look in the mirror in the morning, you are actually seeing a continuation of several, (and perhaps many,) great empires. That grouchy face looking back at you is the latest version, the newest development.

    There is something deep within the human spirit which can never be totally crushed. “Every empire weakens and fades sooner or later,” but a spring follows every autumn.

  65. Ric Werme says:

    Amr Marzouk says:
    November 8, 2012 at 2:57 pm

    > Human sacrifice and flush toilets don’t mix

    Sure they can, you just need something to grind the bones into small pieces!

  66. Ric Werme says:

    But the monuments made no mention of ecological events, such as storms, drought or references to crop successes or failures.

    That seems rather odd for an agarian society, perhaps the priesthood considered itself too important. Perhaps AG data was kept elsewhere on shorter lived media. Here’s a reference that gets to a book of such data, http://en.wikipedia.org/wiki/Chilam_Balam

    https://sites.google.com/site/medievalwarmperiod/Home/drought-and-the-collapse-of-mayan-civilisation says in part:

    Maya historical accounts document two later great droughts between 1330-1334 AD and 1441-1461 AD. As a result of a long (documented) drought in Mexico and the Yucatan in the 16th Century (post-conquest), it has been estimated that half of the then Yucatan population died from famine and disease.

  67. Dodgy Geezer says:

    “It has long been suspected that weather events can cause a lot of political unrest and subject societies to disease and invasion,” Macri said. “But now it’s clear….”

    Several people have pointed out that it has been long understood that the Mayans suffered a catastrophic drought. But the researchers statement was wider – implying that it was an advance in knowledge to apply this more widely to other civilizations.

    The trouble is that this is also wrong. It has been well understood for hundreds of years that climatic conditions can have major impacts. The decline of the classical era was contemporaneous with mass migrations of various peoples from Eastern Asia – this was generally assumed to have been climate change driven, even before scientists understood the first thing about the weather. The history of Egypt is full of political collapses when the Nile went into a drought mode. Historians would not have found this assertion to be novel 200 years ago.

    However, if you want to produce a successful paper to justify your grant, it’s very useful to be able to ‘discover’ something you already know is there. Perhaps I’ll write a paper for a physics thesis, suggesting that a very close approximation to orbital paths can be gleaned if we assume that there is an attractive force between objects proportional to their masses and inversely proportional to the square of their distances. This has been long suspected….

  68. Steve Keohane says:

    Ric Werme says: November 9, 2012 at 5:58 am
    I believe those droughts you mention are coincident with drought in the SW US and northern Mexico, attributed to the demise of the Anazasi at that same time. None of this seems like new information.
    Reading upstream I see I am not alone in seeing the lack of new information being resented. Matt says:November 8, 2012 at 10:47 pm and Tim Ball says:November 8, 2012 at 2:37 pm

  69. John says:

    I think it is true that when the rains failed for years and then decades, it likely became impossible to produce as much food as before, during the heyday of Mayan civilizations. So the cities fought for resources, and I imagine that if they killed enough people, there would be fewer mouths to feed, and the mouths would be those of the victors. When there isn’t enough food, this is what will happen.

    What is at issue is why did rainforests cease to have much rain?

    From what I read, when you are close to complete deforestaton, then when the rains come, they wash away in rivers, and moisture isn’t there to re-evaporate and form clouds and rain downwind. In contrast, when the forests remain pretty much as they were, the rain either goes slowly to groundwater, or re-evaporates from leaves other surfaces to become cloud and rain downwind. In this latter case, there is enough rain, and the crops grow nicely.

    Bottom line: when you get rid of your rainforest trees, you decrease rainfall. Decrease it enough, and you can’t feed a large population.

    Nothing to do with CO2. But certainly shows that ancient civilizations could outgrow their resources and bring their civilization crashing down.

    Turning to the present, my sense is that we don’t have to take very expensive and immediate actions that increase unemployment to avoid catastrophe via CO2. Instead, this is the way to deal with CO2, in my book:

    http://www.foreignpolicy.com/articles/2012/11/05/climate_course_correction

  70. Silver Ralph says:

    .
    Having poked around the Mayan temples for some time, it seems clear to me that each temple was in use for a considerable amount of time, being remodeled and rebuilt on numerous occasions. Yet while this was going on, more and more temples were being built, so the complexes beacme larger and larger, and more of a burden on the economy.

    It seems highly likely that the priestly and administrative section of society grew so large, it outstripped the capacity of the productive side of society to support it. Mayan society collapsed under the impossible demands of the unproductive for an ever greater share of the economy.

    .

    And therein lies a grave warning for today’s society too…..

    .

  71. Silver Ralph says:

    Centers for Disease Control says: November 8, 2012 at 8:16 pm
    Bad weather and catastrophic sea level rise is definitely what killed the Egyptians chasing after Moses.
    ————————————————————

    Yeah.

    It was called the eruption of Santorini / Thera, the largest eruption in historic times. The sea receding in this eye-witness description, was the result of the tsunami on the northern Egyptian coastline (the Sea of Reeds, not the Red Sea).

    How do we know this was the true reason for this account? Because this ancient record also has Moses gathering ash from a furnace and sprinkling it up in the sky, so it fell as ‘small dust’ over the lands of Egypt. Ex 9:8. A better description of the long-range effects of the ashfall from the Santorini eruption would be difficult to find.

    The description of an ashfall, together with a tsunami, confirms that the Exodus account was an eye-witness description the Santorini eruption. There is no way anyone might guess that the sea recedes and returns during an eruption, and so this must be an ey-witness account. (There are other confirmations, like the air ‘being thick and difficult to breathe’ and people being ‘inwardly consumed by this air’ etc etc etc)

    .

  72. rgbatduke says:

    On the one hand, I’m perfectly comfortable believing that climate variations — hell, weather variations — can be extreme enough to topple a primitive, not terribly stable in the first place civilization. This is hardly the only example — in countries like India, the failure of the monsoon (or excesses in the monsoon) has been responsible for the weakening and collapse of countless principalities and more rarely larger states over its 6000 year history (one I’m fairly familiar with from living there when I was growing up). There is little doubt that a seven year drought in 1606-1612 wiped out Jamestown after a similarly severe but shorter drought wiped out the “The Lost Colony” in NC in 1589:

    http://www.ncdc.noaa.gov/paleo/drought/drght_james.html

    Note that the Jamestown drought occurred in rough coincidence with the beginning of the LIA, and had no conceivable anthropic cause.

    The great Dust Bowl of the 30s was a “perfect storm” caused by a perfectly natural drought that lasted from 1931 to 1939 — eight long years — pushing a huge stretch of countryside that was borderline near-desert over the edge into desertification, at precisely the time that settlers had stripped the country of all of its natural protections against the worst effects of drought — removing all vegetation, cutting down all the trees that formed natural windbreaks — so that when the drought happened and the crops themselves withered, there was nothing to hold the soil, nothing to break the wind, and the great plains was covered by dust storms that blew away the topsoil and piled it up into spectacular dunes. As we have excellent historical and scientific records of the occurrence, we can be certain that it happened, we have a good idea why it happened (given the drought, which of course we can no more explain or predict now than then!), and we can be quite certain that if an eight year drought like that happened again the effects would be just as devastating.

    Can it happen again? It may be happening right now, not because of global warming but because we are not warming at the moment. There is a strong correspondence in the paleo drought records between La Nina conditions in ENSO and drought in the western US. The cooler pacific ocean conditions seem to create alterations in the Rosby waves and polar circulation that diverts the subtropical jets poleward. This causes fewer of the tropical eddies that pull in oceanic moisture to flow over the southwestern US. We are currently into the third “aborted” El Nino in a row, where the ENSO meter started up into El Nino conditions only to fall back into neutral or La Nina conditions (it currently stands square at the top of neutral). It is possible that this has something to do with the solar cycle — it is in rough coincidence with the current hundred-plus-year minimum in solar cycle peak activity, just as the very strong El Ninos of the 80s and 90s were in rough coincidence with periods of robust solar activity (and according to Bob Tisdale’s data as well as the UAH records, each produced a “burst” of Hurst-Kolmogorov punctuated equilibrium global warming).

    This is in and of itself rather curious. La Nina seems associated with (on average) neutral to global cooling conditions, El Nino seems associated with (on average) neutral to global warming conditions, El Nino domination provides the US with the warmth and moisture it needs not to be a desert, La Nina with colder, drier conditions that push borderline lands over the edge into desertification. But all of this is still a relatively weak and erratic association, because we are talking about chaotic phenomena — the probability of nucleating a large scale eddy that carries moisture up where it is needed, such that even modulating that probability does not guarantee extremes either way, assuming a slightly antibunched but still rather Poissonian distribution of randomly nucleated events.

    That is, even in an absolutely perfect world with no modulation of the probabilities, every hundred years or so, pure Poissonian distributions of these events will produce trains of years of excess or deficit. I don’t think people really appreciate that. Climate scientists would do well to study things like:

    http://en.wikipedia.org/wiki/Poisson_process

    to understand how large the natural variations of a Poissonian process are, how easy it is for simple coincidence to create long stretches of drought or excessive rainfall even without any modulation of the baseline probabilities. This is all by itself almost solely responsible for the pattern of droughts and excessive rainfall that we see, when one applies the statistic to things like the probability of a blocking high pressure center emerging, and again is associated with Hurst-Kolmogorov distributions of drought events and discussed and described by Koutsoyiannis (whose professional career has been advising Greece — a country that is almost entirely Mediterranean climate borderline desert where water is precious) in his extensive decade-spanning work on hydrology, work that mostly preceded any hint of the “CAGW” hypothesis and that continues to apply today.

    Did we learn from the Great Dust Bowl? A bit. We planted trees and shrubbery and grasses to rebind the soil, but the only reason this “worked” is that the rains returned in 1939 to break the drought. We might avoid the “dust bowl” part of a modern era drought because we do grow winter crops to keep the soil bound, because we do have hedgerows and trees to break the wind, but we’ve committed a different sin this time, one that will very likely have an enormous impact should the current drought continue — as it very likely will — with continuing La Nina and/or global cooling conditions should the latter occur. We’ve exploited the water table itself, drilling wells to help irrigate the surface by pulling water up from the natural aquifers that are nature’s buffer against continuing drought.

    Worse, we’ve taken the major rivers and waterways that drain the region and pulled water out of them all the way to the sea. The Colorado River is primary example:

    http://www.sierraclub.org/rcc/southwest/coreport/

    (don’t worry, this 2001 report doesn’t contain the words “global warming” — it recognized the danger from natural variability given the enormous pressure on the river’s water to support ever increasing populations that were — and continue to be — at ever increasing risk).

    This problem is not confined to the US:

    http://en.wikipedia.org/wiki/Groundwater#Overdraft

    Note well that a primary region cited is the Punjab in India. This is literally next door to where I grew up (in New Delhi) and the land in question is all borderline desert. Groundwater in the region is replenished pretty much one time per year, during the monsoon (when it rains as much as inches per day and causes massive flooding) — the rest of the year rains are extremely infrequent, and the summer months leading up to the monsoon are hot and very, very dry. During this dry season, dust-bowl like dust storms are standard operating procedure in much of India — I used to climb a tree during dust storms and peer through the flying dust as it reduced visibility to less than 100 meters, similar to a heavy fog in the US, trying to keep the grit out of my mouth, nose and eyes.

    During the years leading up to the Green Revolution (which my father was working for the Ford Foundation to bring about) the Punjab and many other neighboring Indian states were borderline desert that would step over the border and become real desert every few decades, then step back when the rains returned. Indeed, famine in India has its own Wikipedia page:

    http://en.wikipedia.org/wiki/Famine_in_India

    This is a sobering read. Note well that the death figures in these articles are given in terms of millions of people, and that the last major famine discussed in the article occurred in the twentieth century across much of the same time frame as the Great Dust Bowl, killing a total of some five million people. Lesser famines occurred in the sixties (we lived in India in the famine of 1966). Most of these famines had drought as the proximate cause in territories that are always a few steps away from being desert, although (as the article points out) in most cases there was adequate food grown in the greater Indian subcontinent and political, economic, and transportation issues contributed to the final death tolls.

    To return to the top article: it is absolutely plausible that a perfectly normal and not particularly improbable drought — a regional drought lasting a mere five to ten years — would be more than sufficient to trigger the collapse of a civilization such as that of the Mayans. Such a drought would kill many in the resulting famine and the plagues surrounding mass death, and would weaken both the social fabric of the society and make it vulnerable to the inevitable outside invaders (or internal ones) as armies defected in search of food and became little more than bands of wandering marauders themselves. Entire city populations might well pack up and move away in search of water, with most of the people dying en route before they ever found it in a vast, dry countryside where those fortunate enough to have some water source would defend it to the death rather than share it.

    The United States is just as vulnerable to this as the ancient Mayans. We know that the probability of a 5 to 10 year drought in almost any part of the US is high enough that droughts of this magnitude occur almost everywhere with a frequency of once per century or thereabouts. Droughts like this have been occurring “forever”, are clearly visible in tree rings, and of course they confound the hell out of attempts to also use the tree rings as proxies for temperature, because the droughts are perhaps more likely than not to be associated with colder than average temperatures rather than warmer, as indeed is predicted by Greenhouse gas theory as humidity is a powerful greenhouse gas!

    Are we prepared for this? Of course not. In fact, our government is almost as bad in this regard as the governments of ancient times, pretending that some particular climate pattern is normal and that extreme events do not occur, or if they do, that they are somehow our fault and can be avoided if we appease the gods.

    That’s what is so very scary about both the catastrophic anthropogenic “climate change” hypothesis and the skeptical counter arguments. Let’s parse them into pieces, backwards.

    Climate Change: There is absolutely no doubt that “climate change” occurs. Always. There is no such thing as “normal climate”, or “stable climate” — those terms are only the result of our natural tendency to infer that tomorrow will be like today because to our direct personal experience so far that’s the way it has worked out. I deal with this cognitive problem in physics all the time — students presented with a sheet of paper and a block, who are asked to pull the sheet of paper out from under the block and then explain the direction of the frictional force and acceleration almost invariably get the direction of both wrong, because they mentally jump onto the frame of the paper and see only the block moving backwards relative to the paper. The same perception-centered error leads us to speak of pseudoforces such as “centrifugal force”, to underestimate the range of variability of almost any real-world system, to trust that tomorrow will be like today, if only we do not offend the gods.

    Humans on both sides of the skeptical climate fence sin in this regard, but skeptics sin less, recognizing that one swallow does not make a summer and one Sandy does not validate a hypothesis that the climate is more variable than it has been in the past, given that if anything we almost certainly underestimate that past variability just because we can’t remember it, have no historical records of it, and truthfully it often — perhaps usually — leaves remarkably little enduring paleo/proxy trace. This underestimation of variability has a huge effect on the Bayesian estimation of possible human impact — a mere glance at the proxy derived thermal history of the Holocene, let alone the last 50 million years, suffices to substantially weaken any argument for anthropogenic impact at the global level because there is far more noise than we are allowing for when we try to resolve a hypothetical anthropogenic “signal”.

    Anthropogenic: Personally I have no doubt that humans have had an impact on the climate. Two specific instances are the Great Dust Bowl, where one can argue that average temperatures would have been substantially different over a continental-sized chunk of the Earth’s surface if that surface was still undisturbed naturally (evolved) drought-resistant grassland and forest when the drought began instead of mechanically cultivated and overfarmed bare topsoil when the first crop failures occurred. Also, the vast quantities of dust no doubt altered everything from snow albedo to atmospheric transparency over an equally vast region. Then there are the deserts of North Africa, very probably caused by the introduction of goats that ate the scrub grass and trees that protected that region from the same fate thousands of years ago. Does the Sahara have an enduring impact on global climate? Of course it does, and humans very likely helped to create it. Human impact may be small (on a global scale) and somewhat localized, but in a chaotic system even small changes can have large impact, given time.

    That doesn’t really help us here, because we don’t know and cannot predict those changes because the system is chaotic, and because we don’t understand it well enough to predict even its normal variability, to be able to answer the question “if the human race had never evolved, what would the climate/weather outside be right now?” or any of the even simpler “what if” questions one might ask, what if the CO_2 level was 280 ppm, what would the climate be, what if humans died off tomorrow, how would the climate evolve. We have no clue — not any clue with significant predictive value. A chaotic system could easily all by itself have produced 100% of the climate variation observed over the last two centuries (in the thermal historical era), or humans may well have had a significant impact only we don’t know what that impact is. We don’t even know for certain what the sign of that impact is — GCMs have to balance positive GHG influences on climate against negative aerosol influences (where I could wax poetic of the numerical dangers that abound in differential systems that rely on the partial cancellation of two opposing terms when any part of the parameters implicit in those terms are set by fitting the system to a historical dataset, but won’t, unless I just did). The overall impact could actually be negative or neutral, or weakly positive, or strongly positive, or overwhelmingly positive and lacking an objective baseline or convincing theory we can do no better than assign rather weak probabilities to all of these possibilities.

    So sure, humans have almost certainly impacted the climate, and will probably continue to do so. We just don’t really know how much, where, or why. We don’t know of the anthropogenic changes have been (on average) beneficial or harmful or (most likely) irrelevant as humans have done as they always have done, and adapted to them (or died from them) in real time as they occurred. When Tambora exploded, it altered the climate for at least a decade afterwards, and sure, it killed a lot of people from climate change on the opposite side of the globe from where it occurred in “the year without a summer” and beyond. When humans were touching off nuclear bombs every few weeks on remote south pacific islands, in central Eurasia, in the southwest US, in some sense they were creating a fifty year stretch of unending Krakatoa. When the firestorms of Word War II were torching entire cities and releasing massive amounts of war chemicals into the air, it may well have had an impact. As rising populations have drained rivers dry, tapped groundwater, dumped nutrient-rich agricultural silt into oceanic estuaries, cut down forestland and replaced it with shopping malls and concrete, and blanketed millions of square miles with industrial aerosols and easily measurable CO_2 anomalies, it very likely has had an impact. In each case a small impact because the Earth is really rather big, but see above on natural variability and chaotic systems with multiple feedbacks.

    We do not know how significant any one of these things have been, or how they have worked together to add or partially or even completely cancel. We do not know what the climate would be like if we went back in time and altered any particular one of them to an entirely different value, then tracked the climate’s evolution with just that one change. We do not know not because one cannot do this with GCMs, but because GCMs don’t do particularly well at hindcasting or forecasting the climate as it is with the actual data, because they contain driving terms that partially cancel in a powerfully nonlinear system, and because they don’t even have terms for some of these things — what is the net global climate impact of an algae bloom caused by runoff and silt emptying into the Gulf of Mexico or Bay of Bengal? Surely larger than that of the wings of a Brazilian butterfly, one would think. But the truth is that we don’t know.

    So really, the best skeptic and catastrophist alike can do is acknowledge that humans likely are having some impact on climate, that we don’t know what it is and are unlikely to be able to find out in the immediate term with only 30+ years of halfway decent global climate data (far less than this for the 70% of the Earth’s surface covered by the ocean) and a mere smattering of halfway decent solar data, period. We’re a long, long way from being able to know what is going on inside the Sun in any sort of detail, and it is pretty clear that we do not yet completely understand the complete effect of the state of the Sun (past as well as present, as this is a non-Markovian problem) on the ongoing evolution of the climate.

    Catastrophic: And finally, we get to the key problem. The risk of catastrophe. Again, skeptic and catastrophist alike should take a look at the proxy derived climate record, supplemented as best we can by actual historical records from the 6000 or fewer years where such records exist (you can learn a lot even from cuneiform tablets from the Sumerians, for example, because they were bookkeeping records for things like crops and cows). Then, we should all be afraid, very afraid! Screw the anthropogenic variability — mother nature all by herself is a source of literally unending climate catastrophes that strike all over the world in turn!

    Here is where the human species has a very narrow window of time to grow up. Forget global warming or “anthropogenic climate change” per se. Forget the start of the next glacial era too, even though IMO that is nearly certain to occur “soon”, just because we don’t know what soon is, lacking any sort of quantitative model that could plausibly predict it, with or without anthropogenic modifications. Look only at the normal sorts of climate catastrophes — the Mayan drought, the droughts that killed millions of humans in India over a mere two centuries, the monsoon floods. Look at the year without a summer and the impact on the weather of natural events like El Nino and volcanic explosions. Look at the impact of mere blizzards or hurricanes out of place, where blizzards or hurricanes are never really “out of place”, only out of the memory and experience (maybe) of the people living in the places where a rare one hits. Abnormal weather, abnormal climate, is perfectly normal, the rule itself not the exception.

    And it is indeed not infrequently catastrophic.

    We help make it so. “Sandy” in the 1350s would have torn up a handful of coastal native american communities and then left not the slightest trace as those communities were prehistoric an lacked a written language and normal weather and other storms constantly erase the past and overwrite it with the latest “big” events of the present. “Sandy” in the 1600s did impact “civilized” communities on the seaboard, but there weren’t many such communities and the people in them were phlegmatic, considering catastrophic natural disasters to be god’s will and something beyond their control to be endured. “Sandy” in the early 20th century did a lot of actual damage to human institutions and communities and killed a lot of people, but again, there weren’t THAT many people and it wasn’t our fault that the hurricane itself occurred, it was only our fault that we built entire seaside communities as if hurricanes with this degree of violence would never occur.

    A mistake that we then repeated, only tenfold, over the next 75 years, so that when the real Sandy hit it did truly catastrophic damage. Why? Not because of “anthropogenic climate change”. Not because of carbon dioxide. Because we build the entire Eastern Seaboard as if hurricanes of that strength never happen there!

    Cheeze. How dumb can you get?

    We continue this idiotic “blindness” right on today. Durham NC, where I live, is in a comparatively wet part of the world. We have on average nearly perfect rainfall — a rain anywhere from every few days to every few weeks, sufficient to keep the water table high, the lakes and rivers full, the farmers reasonably happy. Still, there is a finite volume of water flow in those (mostly impounded) lakes and rivers. Durham has two city water reservoirs, both lake impoundments of small rivers, plus the capacity in principle to draw on two more much larger impoundments in or next to the city that are in fact used to provide water as far away as Virginia. Chapel Hill (a stone’s throw away but that’s an uphill thrown stone as it really is on a “hill”, or ridgeline, stretching from Chapel Hill to Hillsborough (right behind by house). Chapel Hill has an impoundment as well but it is uphill and doesn’t get as much flow.

    In the 80s we had two memorable droughts, each one a few years long and only a couple of years apart. In the 2000s we had another drought that lasted a couple of years. Again, nothing whatsoever remarkable about this, and if you go back in the records for the region you see many examples of similar patterns of events over well over a hundred years. Yet the 1980s droughts nearly drained the city water reservoir — I used to fish there at the time and remember driving my car miles down into the reservoir basin itself into what used to be ten or fifteen feet of water to park it next to the water to fish. They opened the second reservoir in time to do better (but still pretty badly) in the second 80s drought — it doesn’t help that much to have two reservoirs if the reservoirs are being fed by a literal trickle of water instead of a small river, especially if you use the water itself to drive the pumps that fill the city tanks ten or twenty miles away. Chapel Hill suffered (and continues to suffer) much more than Durham — their reservoir is tiny and empties almost immediately anytime there is a drought.

    Over the next twenty years, what did the city do? Did they impose a moratorium on new construction, take measures to limit the population, given that nature had conclusively demonstrated that we were at or near the natural carrying capacity of the land as far as human population is concerned given the known natural variability of climate?

    Don’t be daft. There is money to be made building new houses. More taxes. More money for real estate agents and builders. More people to buy more food, more services, more cars, to run more companies with more jobs to offer. And when it rains normally there is plenty of water!

    Enter 2000, and once again the city reservoirs — now both of them — pretty much ran out of water. Chapel Hill had nearly doubled in size in the intervening 20 years and rationed water to the point where they wouldn’t serve you water in a restaurant unless you asked for it, and to where they served you on paper plates to avoid having to wash dishes. Durham didn’t get that bad, but watering your lawn outside of some narrow time window became illegal, and the idea of “natural” yards that have drought resistant plants instead of grass at all briefly flourished. The rivers subsided to a trickle, and all the downstream communities (all of them constantly growing, ever increasing the peak demand on a finite and erratic resource) suffered as much or more than Durham.

    The drought ended once again — as droughts do — and some hurricanes refilled the reservoirs to literally overflowing in a matter of a few days as floods replaced droughts — the natural cycle observed over thousands of years. We had a hundred year record snowfall in there, a five hundred year flood, a few decade record dry or hot days, weeks, months, years — business as usual, in other words. Weather extremes are normal as soon as you look a century or better timescales instead of the half-century or so of our “typical” living experience.

    Did we learn even from the 2000 droughts? Of course not. Why do you think real estate agents run for city councils? Block that kick! There is always room for one more house, one more development, one more tap suckling at Mother Nature’s watery tit and surely we won’t ever have another drought, will we? Or at least, we won’t have it until I’ve made my money from the new houses, and who cares about a little thing like water rationing anyway?

    To conclude, my own opinion is that if the human species deserves to survive, it needs to get its act together and use its rather extensive knowledge of history to learn from it and act on it to avoid the extreme events that we know with absolute certainty await us in our futures. We know that over a roughly hundred year time frame, there will be at least one major earthquake (even in relatively stable parts of the world). There will be multiple multiyear droughts, and a few nasty floods to balance them out. In North Carolina we can absolutely count on being hit by at least a half dozen “catastrophic” (cat 3 or better) hurricanes, with a number of them coming inshore and roaring over the top of my house where I type this like Fran did, still at least a category one, doing catastrophic damage to any structure that was designed and built as if this could never happen. We can count on tornados that at the very least pass by close to our houses, if not right over them or through them. Either we design and build our cities, organize our entire culture from the farm to the heart of downtown, as if these events will occur or we have nobody but ourselves to blame for the catastrophic costs that follow when they do.

    Of course no amount of building codes or careful planning can avoid all risk, so thoughtful insurance both personal and federal is called for, where the latter should be provided (really) only to those people and institutions that weren’t damn fools and built ticky-tack houses right on the coast or down in a flood plain in spite of the near certainty of the house’s demise in due time.

    This, not “carbon regulation”, is what we should be doing in response to “climate catastrophes”. Screw CO_2 — with it or without it, climate catastrophe is certain every few decades or centuries. Should we be worrying about catastrophic ocean rise? Not particularly — there is absolutely no evidence that anything like that is occurring, and there is time to take action once there is. Should we be worrying about another five meter or better storm surge anywhere on the East Coast of the US? Damn skippy, because we can be certain of this — it happens somewhere literally all of the time, almost every year, and it happens everywhere given enough time. SHould be we worrying about an Anthropogenic Global Warming produced drought and subsequent Dust Bowl? We should be worried about massive droughts period, because with or without anthropogenic influences, Dust Bowl-scale droughts are certain to occur, nearly everywhere. Those who do not learn from the past are, indeed, doomed to repeat it until they get it right.

    Most of the measures we should take to deal with “climate change” should be taken no matter what because climate change is normal, weather extremes are normal, and we have thousands of years of human history to draw on to back up either assertion. Only complete idiots and greedy fools willing to gamble (with other people’s money, inevitably) think otherwise.

    With that said, I think that one should be — concerned is the right word, I think — about the possibility that increasing CO_2 might increase the variability of the climate or alter the trajectory of the climate in negative ways. It is difficult to argue convincingly that this is impossible, just as it is difficult to argue convincingly that it is certain. Most likely it will have an effect that will be nearly impossible to disentangle from the substantial noise and natural variation of the climate, an effect that almost certainly will be positive in some ways and negative in some ways and we don’t even know enough to sort that out to properly balance the costs and benefits.

    Should our concern be great enough to take action and limit CO_2 production?

    That’s a very difficult question, one that is strictly a cost-benefit problem and requires a cost-benefit analysis. My own take on it is that the answer is a very limited yes. Yes we should — as a matter of public policy — encourage the development of safe and cost effective energy resources, such as nuclear power (a no brainer) and solar power generation and storage. We should pay special attention to ensuring that human civilization continues to endure and flourish as we work on this by not shutting off the power or impeding the development of energy resources in the third world — not while our knowledge of cause and effect here is so limited that we cannot make anything like accurate predictions of comparative outcomes.

    rgb

  73. Don Worley says:

    Cannot be true.

    The mayans were such nice people. They knew that extracting oil and gas from the devil’s domain was wrong.

    Must be some other cause, such as low tax rates, not enough human sacrifice or something similar.

    /snark off

  74. Matthew R Marler says:

    This has been reported before for some areas of the Mayan civilization.

    More Tabloid Climatology

    Do you have a criticism of the paper? You wrote “Seek and you shall find it”, but in scientific research what is sought is sometimes not found; the finding of what might not have been there is usually evidence in favor of a proposition. You are not really denying, I hope, that climate change can end civilization, at least in some places, as it has in the past. The issue is independent of whatever change might be due to CO2 change.

  75. Tamara says:

    I thought humans evolved in a stable climate that was “just right”. Extreme weather is caused by burning fossil fuels post-1750. /sarc

  76. Matthew R Marler says:

    rgb at Duke: Because we build the entire Eastern Seaboard as if hurricanes of that strength never happen there!

    Cheeze. How dumb can you get?

    Good essay. About that quote, right now there are people advocating that we spend many resources reducing CO2 emissions instead of preparing for the next hurricanes, droughts, fires etc. This even though the natural disasters will recur even if we can reduce by targeted amounts, and even if that “works” to halt the warming. I am not sure “how dumb” people can be, but I bet that Mayor Bloomberg even now thinks that trans fats and soda pop restrictions are more important than preparing New York City for the next storm. I don’t know him, this is a kind of guess. Let’s see where he devotes his attention and the city’s resources through the remainder of his term.

  77. Ric Werme says:

    Steve Keohane says:
    November 9, 2012 at 6:38 am

    Reading upstream I see I am not alone in seeing the lack of new information being resented. Matt says:November 8, 2012 at 10:47 pm and Tim Ball says:November 8, 2012 at 2:37 pm [and Ric Werme says: November 9, 2012 at 5:58 am]

    Yes, but that’s okay. Replicating results increases confidence in the hypothesis.

    It’s just that it’s not major news any more.

  78. agfosterjr says:

    “They were incredible craftspersons…” A new wordification for me, but like ‘spokesperson,’ ‘chair,’ etc. –conceived in ignorance and born in stupidity. It is the same originally neuter element ‘man’ that shows up in ‘woman,’ that is, the ‘wiffman,’ or the man who was wife. The science behind these neologisms has much in common with GW science–there is none.
    –AGF

  79. Don’t mind me, but I read that changes in rain fall and droughts triggered the Maya collapse at least 10 years ago. As an aside, apparently a group of Mayans migrated northward and finished off the Anasazi culture shortly afterward. Signs of cannibalism and changes in fortifications built by the Anasazi appear at the same time, shortly before the whole area was abandoned around 1300 AD.

  80. bubbagyro says:

    ferocious20022002 says:
    November 9, 2012 at 3:56 pm

    You are correct. I was just going to add that fact about the Anasazi..

  81. E.M.Smith says:

    In the Dresden Codex, IIRC, the 2012 date is signified by jugs of water pouring from the sky.

    The Maya did predict a lot of things, and one they predicted was that in 2012 the grand cycle would turn (not the end of the world, though) and it would be accompanied by massive rains.

    As we’ve started having rainfall ramp up all over (during the solar funk / cooling cycle swap) I suspect “they were onto something”. These folks studied more astronomy and cycles than even modern folks do. I think they worked it out some time back how cyclical weather happens, even very long cycle weather. Too bad the Spaniards burned all their books…

    BTW, there was also a “Mega drought” in California. Some of our lakes have full sized tree stumps on the bottom. The droughts lasted long enough for the lake to dry out and trees to grow to maturity at the bottom. Then the rains returned… About the same time, too, IIRC.

    I’ve also found a pattern where, when it is colder, some places get less rain and others get more. In particular, California had a drought in the ’70s (after a period of high snowfall in the ’50s). We seem to get lots of snow on a ‘warm to cold’ transition, then drought toward the end of the cold phase when we go into a ‘cold to warm’ transition. To the extent that holds, we ought to be lots of snow for a couple of years and then a very bad drought as this cycle turns from hot to very cold.

    Oh, and Utah too. Back around the ’50s the Great Salt Lake had flooding from lots of rain, then the rains slacked off a lot as the cool phase settled in. About ’56 I think… So I’d expect that pattern to repeat in Utah too (though they added pumps and stuff to prevent more flooding… just in time for drought to leave them unused for decades…. so a repeat minus the floods.)

    THE key takeaway from that paper OUGHT to be that there are strong and long natural weather cycles and we ought to be preparing for them. Forget the CO2, it is not relevant. It’s the natural cycles that’s a problem…

  82. Spector says:

    It also appears that the Old Kingdom in Egypt was destroyed by a drought that greatly reduced or completely stopped the flow of the Nile about 4200 years. There is evidence that a worldwide, short-lived, period of very cold temperatures. A Text have been found, which describes a massive famine punctuated by unspeakable horrors occurring along the Nile at the time.

    Ancient Apocalypse Death on the Nile
    “Published on Apr 24, 2012 by English Video”
    10 likes, 0 dislikes; 1,856 Views; 48:59 min
    BBC Series
    “Professor Fekri Hassan attempts to determine why the Egyptian Old Kingdom, the civilisation of the great pyramids, collapsed around 2200 BC. Can science show that terrible forces of nature were to blame – even driving people to cannibalism? Clues come from the remote deserts of southern Egypt, the glaciers of Iceland and a dramatic and unique archaeological find in the Nile delta.”

  83. Galane says:

    Was that stalagmite wet when they broke the irreplaceable geologic feature from the cave floor? If it was dry it was useless as any sort of accurate gauge because dry stalagmites and stalactites have stopped growing, thus they can’t be back-dated from the present – at least nowhere near as accurately as a growing one. Same deal with examining growth rings of dead VS live trees.

    As for problems with growing crops in South America, quite a lot of that Amazonian jungle isn’t natural. http://en.wikipedia.org/wiki/Terra_preta Humans practiced deep tillage, in some places up to six feet, of charcoal, manure, bone and other organic materials to improve the typically poor soils covered by a thin layer of fertile soil.

    The way to “save the rainforest” is to restart that practice. Compost all kinds of organic waste and build giant tillers to mix it into the ground up to six feet deep across as much of the “expired” farm land as possible. In a few years it would be possible to create as much Terra preta as the ancients did in 1,000 by manual methods.

  84. Steve Keohane says:

    Ric Werme says:November 9, 2012 at 10:35 am

    Steve Keohane says:
    November 9, 2012 at 6:38 am

    Reading upstream I see I am not alone in seeing the lack of new information being resented. Matt says:November 8, 2012 at 10:47 pm and Tim Ball says:November 8, 2012 at 2:37 pm [and Ric Werme says: November 9, 2012 at 5:58 am]

    Yes, but that’s okay. Replicating results increases confidence in the hypothesis.

    It’s just that it’s not major news any more.
    I know, but I heard this at least 30-40 year ago.

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