Flagrant Attempt to Mislead the Public about the Holocene Onset

As I noted last week, there is a new article in Nature that tries very hard to prove that CO2 increased prior to the warming at the onset of the current interglacial which is known as the Holocene.  I read the article and was stunned by the conclusion and the charts which clearly showed that the warming took place after the CO2 rose.  Since I have extensively studied much of the available data from the period 10-20k years ago, I knew right away that this paper did not give the same conclusion as any of the other data.

Last week I was also busy with work and didn’t have sufficient time to delve into the data, but I had time to consider how such a result could be achieved using real data.  I considered this with the idea of how the Earth’s climate really behaves.  The Holocene began because the orbital parameters changed so that the Northern Hemisphere started to receive increased energy from the Sun starting 22,000 years ago.  Any warming that took place would have been evident first in the NH.  As the warming pushed back the ice caps and glaciers in the NH, the dynamics of the Earth change and a full interglacial period develops which is what causes the warming in the rest of the world.  The key is the NH.

When I looked closely at the charts that were in the press release, I noticed the first curious item.

The Inconvenient Skeptic

Charts available from the BBC article.

The critical point used in the Nature paper is 17,400 Years before Present (YBP).  That is when the CO2 level starts to show the discussed rise.  The Antarctic temperature is rising prior to that, but the global temperature only rises after CO2 increased.

While I didn’t have time to review all the data I have on this, I was able to consider how to create the above charts.  The key part would be to focus on the locations that would see the warming last, which would be the Tropics, especially the Tropical oceans.  Those locations see the smallest change in temperature, but it really takes a big change globally to change the temperature in the tropics.  So if I wanted to re-create the above charts, I would weight everything towards the tropics and use as little data as possible from the Northern Hemisphere.

The Inconvenient Skeptic

Locations of the temperature reconstruction

The temperature reconstruction they performed was what I expected and more.  They included only two ice cores from the Northern Hemisphere and used 4 pollen reconstructions from Alaska.  The only place a pollen reconstruction included in their study are the ones in the upper NH, which in turn makes them the majority of the studies from the NH.  A vast majority of the overall data sources used were ocean reconstructions between +/- 30° latitude.  Any combined temperature reconstruction from this source of data will show very little global temperature change and it will take place much later.

That is precisely what the reconstructed global temperature chart shows.  It shows that the Earth was only 3.6 °C cooler at the depths of the last ice age.  The only way to achieve that result is to weight the study in such a way that the tropics dominate the overall temperature.  This will also show a delay in the onset of warming.

I also found the following chart in the supplementary information with the Nature study.

The Inconvenient Skeptic

from page 31 of the Supplementary Information.

The breakfit is a practical method of determining when noisy data changes trends. Climate data is always very noisy so this is a useful way to show changes.  Of course if I do the same thing for the data from the Northern Hemisphere, the results are slightly different.

The Inconvenient Skeptic

(Green) Greenland Ice Core, (Blue) Antarctic Ice Core, (Red) Breakfit of the Greenland Ice Core.

The earliest detected rise in the atmospheric CO2 level was 17,400 YBP.  The ice cores in the NH show that warming started to take place ~19,800 YBP.  Which is ~2,400 years before the global CO2 levels started to rise.  That point ~17,000 YBP when the temperature dropped in the NH coincides with a meltwater pulse.  Those take place when massive freshwater lakes that have formed on ice caps flow into the ocean and disrupt the ocean currents.  That is the point where the rest of the Earth starts to catch up with the warming that was already well under way in the Northern Hemisphere.

The paper in Nature is a very deceitful attempt to portray the Earth’s temperature as dependent on the level of CO2 in the atmosphere.  The weighting of locations to the places to warm up last and the overload of pollen reconstructions in the Northern Hemisphere all ensure that the final result showed that warming took place much later.  This article is one of the most intentionally misleading ones I have ever come across.

Posted in Bad Science and Cause and Effect and Climate by inconvenientskeptic on April 9th, 2012 at 10:06 am.


This post has 8 comments

  1. One thing that puzzled me was that the temperature according to the Shakun graph seems to lag CO2 by between 1000 and 2000 years.

    Any GHG warming should in theory occur within a few years or decades at most. And I cannot believe any proxies from 12000 years ago could be dated so accurately.

  2. inconvenientskeptic Apr 10th 2012

    The argument is constantly made that it will be 1,000 years before the Earth sees the warming from the CO2 in the air now. So that delay of thousands of years is no surprise to me.

    Some proxies can be fairly accurate for the past 20,000 years. After that the dating becomes a bit more challenging. He could only do something like this for the onset of the Holocene.

  3. Bernard Fisher Apr 10th 2012

    Why do so many scientists believe that CO2 is such a potent greenhouse gas? How do they get papers into such a prestigious magazine as Nature when there is as much doubt as there is about the data?

  4. gail combs Apr 13th 2012

    Bernard Fisher, to answer your question you have to look at the politics.

    In 1970 Kissinger said: “Who controls the food supply controls the people; who controls the energy can control whole continents; who controls money can control the world.” If you control CO2 you control energy.

    Two years later in 1972, while the news media was still proclaiming the coming Ice Age, Maurice Strong chaired the UN’s First Earth Summit.

    Elaine Dewar wrote in Toronto’s Saturday Night magazine:

    “It is instructive to read Strong’s 1972 Stockholm speech and compare it with the issues of Earth Summit 1992. Strong warned urgently about global warming, the devastation of forests, the loss of biodiversity, polluted oceans, the population time bomb. Then as now, he invited to the conference the brand-new environmental NGOs [non-governmental organizations]: he gave them money to come; they were invited to raise hell at home. After Stockholm, environment issues became part of the administrative framework in Canada, the U.S., Britain, and Europe. “

    If you look at the IR absorption of water vs CO2 and the amount and variability of water in the atmosphere vs CO2 ~ ranging from 10000 PPM to over 40000 PPM for water vs 400 ppm for CO2, the idea that CO2 is some sort of “Control Knob” for the climate becomes completely laughable.

    Think about it. Even according to this paper the warmists acknowledge the Milankovitch cycle meant more Solar Energy hit the earth. This sublimed the ice and tossed tons of water vapor directly into the air. Since the earth was half desert at the time this was a radical change in the composition of the atmosphere, It meant the addition of tons of water, a greenhouse gas, clouds and additional water on the land in in the sea and yet it is all ignored in favor of insignificant CO2!

    Map showing extreme deserts during the Last Glacial Maximum (18,000 c-14 year ago)

  5. inconvenientskeptic Apr 13th 2012

    My book doesn’t get into the politics of why groups are pushing for global warming, but it does cover the science aspects including the climate at the LGM and the IR absorption. Even has some new stuff. :-)

  6. Richard B. Woods May 5th 2012

    I’m not sure the comment I just tried to post went through. (If it did, then please just delete this one.)

    Re: “A vast majority of the overall data sources used were ocean reconstructions between +/- 30° latitude.”

    On a sphere, one-half of the surface area is between +30 degrees latitude and -30 degrees latitude. (Look up the formula if you don’t believe me.)

    By my count, 41 of the 80 “Locations of the temperature reconstruction” are between +30 and -30 degrees, which is almost, but not quite, exactly half of the total. How, then, do you justify characterizing that as “vast” majority? Isn’t 41 the smallest possible majority of 80?

    Re: “So if I wanted to re-create the above charts, I would … use as little data as possible from the Northern Hemisphere.”

    By my count, 49 of the 80 locations are in the Northern Hemisphere, and only 31 are in the Southern Hemisphere.

    How does using 49 northern points, out of 80 total, constitute using “as little data as possible from the Northern Hemisphere”?

  7. Richard B. Woods May 5th 2012

    Oh, I forgot to say in my preceding message:

    Since half of the globe’s surface area is between +30 degrees and -30 degrees, isn’t it only fair and arithmetically correct, when forming a _global_ average, to have half of the sample locations between +30 degrees and -30 degrees? And isn’t 41 almost exactly half of 80?

  8. inconvenientskeptic May 7th 2012

    It is the area north of +60 that matters. It is that region that experienced the change. That is the area that was misrepresented.

    Which location changes more January to July:
    Minnesota or Miami? They are trying to use Miami to measure changes in Minnesota.

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