Skip to content

The Little Ice Age In South America

June 15, 2015
tags: ,

By Paul Homewood 

 

There has been some discussion recently about the role of the sun in climate change. This paper was published in 2006, but is still relevant in this respect.

 

image

http://www.geo.umass.edu/faculty/bradley/polissar2006a.pdf

 

ABSTRACT

image

 

 

The introduction goes on to make some significant points:

 

 

 

 ScreenHunter_2184 May. 31 19.32

 

image

 

We can note that:

1) The Little Ice Age was a “significant global event”.

2) The LIA in Venezuela can be linked to changes in solar activity.

3) During most of the last 10,000 years, glaciers were absent from all but the highest peaks in the Cordillera de Merida.

 

 

There is some more detail:

 

image

 

As well as the references to the de Vreis and Gleissberg oscillations, there is a very telling comment about to “the absence of a glacier in the watershed before approximately AD 1100”.

 

The paper also finds that paleoclimate records from other tropical sites support our interpretation of the glacier and sedimentary records in Venezuela.

 

The conclusion from all of this is that glaciers in this part of the world are actually pretty unusual, and really only became common during the Little ice Age, for which there is strong evidence that solar oscillations were responsible.

The fact that they have now been melting back since the mid 19thC should come as no surprise to anybody. The idea that it has anything to do with AGW is frankly ridiculous.

7 Comments
  1. John F. Hultquist permalink
    June 15, 2015 11:31 pm

    From the abstract:
    These results highlight the sensitivity of high-altitude tropical regions to relatively small changes in radiative forcing, implying even greater probable responses to future anthropogenic forcing.

    The “radiative forcing” mentioned must be solar short-wave, essentially visible light.
    It is a great leap of intuition, as indicated by the words ‘implying’ and ‘probable’, to get from there to ‘anthropogenic forcing’ (AF).

    They must mean, for AF, use of fossil fuels, and the addition of carbon dioxide to the atmosphere that then warms. The correlation of these 2 things over the last 18 years seems to be zero. I therefore think the statement in the Abstract is there to assure them of future funding. The science is wanting.

    The parts about glaciers are interesting though.

  2. Ben Vorlich permalink
    June 16, 2015 6:32 am

    Even with all this they do manage to mention “anthropogenic forcings” are going to make things worse than believed previously.

  3. June 16, 2015 11:26 am

    Reblogged this on the WeatherAction News Blog.

  4. manicbeancounter permalink
    June 16, 2015 8:13 pm

    The 3.2C fall in temperatures in the LIA is worth comparing to modern data. Unsurprisingly there are no weather stations at 3000m altitude where the glaciers reside.
    The only GHCN weather station in the Venezuelan Andes is in the city of Mérida (full name -Santiago de los Caballeros de Mérida) which is about 1600m above sea level. The GHCNv2 (raw) data shows a high degree of temperature volatility, though records prior to 1950 are framentary. For instance there was over 2C of temperature rise from the mid-1950s to 1960.
    http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=314804380000&dt=1&ds=1

    The GISS homogenised data tells a different story. As the climate variation is the mountains is quite different from at lower altitudes, to make data homogeneous with heterogeneous climates means breaking up the data. The algorithms just discard the data are being erroneous. So the 2.5C of warming is zero. Pre-1950 data is discarded and the post 1980 warming is vastly reduced.
    http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=314804380000&dt=1&ds=14

    The Venezuelan Andes are not only an indication of a LIA in South America. In addition they undermine the belief that homogenization only removes measurement biases. It also removes the massive diversity in temperature trends that exist.

    • Jack Broughton permalink
      June 19, 2015 8:17 am

      So far I have not looked very carefully at the homogenised temperature info as it is so difficult to get a handle on and this leaves me very impressed by those who are examining them. However, I digitised the two graphs for a simple assessment and found, I suppose the obvious: the raw data indicate a very uncertain rise rate of 1.2 deg K / century but the mean is 19.2 C with more outliers in the +1 standard deviation range between 1998 and 2010.

      The adjusted data indicates a much higher rise rate of 1.6 deg K / century by picking the low of 1943 to start their assessment and reducing the past temperatures by .4 deg K / century.
      The frightening thing is that the adjustments are systematic and biased, as Paul has explained many times,

      No wonder that the pope has now got involved, the arguments about inaccurately measured and altered data and belief in these is the basis of the new religion, and he has decided to usurp it: however, he seems to have forgotten about the population-growth implications on energy demand and climate???

      It is also interesting that the homogenisers ignored the low temperatures reported in the mid 1950s from their assessments. This temperature trending and homogenising is more of a minefield than I had realised.

      • AndyG55 permalink
        June 19, 2015 11:27 am

        “he seems to have forgotten about the population-growth implications on energy demand and climate”

        Also the population -growth demands on food production.

        The ONLY source of all food on this planet is a little process called photosynthesis.

        Photosynthesis requires sunlight, H2O and CO2.

        Plenty of sunlight,
        Decent engineering can generally provide water if rain doesn’t…

        Its the CO2 that will be in SHORT SUPPLY !!!

  5. THX1138 permalink
    June 16, 2015 9:47 pm

    If they hadn’t included the term “anthropogenic forcing”, their work would not have been published, plain and simple.

    Another thing to consider regarding solar activity and variations in surface temperature on earth: It’s cosmic rays.

    “When the Sun is active, its magnetic field is better at shielding us against the cosmic rays coming from outer space, before they reach our planet. By regulating the Earth’s cloud cover, the Sun can turn the temperature up and down. … As the Sun’s magnetism doubled in strength during the 20th century, this natural mechanism may be responsible for a large part of global warming seen then.” (Henrik Svensmark)

    The galactic cosmic ray (GCR) warming hypothesis is based on the premise that GCRs can “seed” clouds, and clouds reflect sunilight. So if there are fewer GCRs reaching Earth (because a strong solar magnetic field is deflecting them away), the hypothesis says there will be fewer clouds, more sunlight reaching the Earth’s surface, and thus more global warming.

    So more solar activity means a stronger solar magnetic field, which means fewer GCRs reaching Earth, which hypothetically means fewer clouds and more warming.

    The warmists reject this claim, because they accept the manipulated temperature data as being fact, showing dramatic warming of the climate, ergo this theory must be wrong.

    Back in the day, we used to put blinkers on horses, but now, it seems, we put them on “scientists” as well.

    More support for Svensmark’s cosmic ray modulation of Earth’s climate hypothesis | Watts Up With That?
    http://wattsupwiththat.com/2014/04/10/more-support-for-svensmarks-cosmic-ray-modulation-of-earths-climate-hypothesis/

Comments are closed.

%d bloggers like this: