Wednesday, January 16, 2013

Global Warming: A Geological Perspective


A paper titled "Global Warming: A Geological Perspective," published in Environmental Geosciences, and summarized below in Arizona Geology, should be required reading for all climate scientists. The paper notes that if 
"the temperature increase during the past 130 years reflects recovery from the Little Ice Age, it is not unreasonable to expect the temperature to rise another 2 to 2.5 degrees Celsius to a level comparable to that of the Medieval Warm Period about 800 years ago" 
and that 
"Climatic changes measured during the last 100 years are not unique or even unusual when compared with the frequency, rate, and magnitude of changes that have taken place since the beginning of the Holocene Epoch.  Recent fluctuations in temperature, both upward and downward, are well within the limits observed in nature prior to human influence." 
Sadly, most climate scientists fail to study or understand the geologic history of climate, which has led to countless false claims that today's climate is unnatural, extreme, unusual, or unprecedented.

From the summary paper:

A review of research on past temperatures and variations led us to the following conclusions:

1.  Climate is in continual flux: the average annual temperature is usually either rising or falling and the temperature is never static for a long period of time.

2.  Observed climatic changes occurred over widespread areas, probably on the global scale. 

3.  Climate changes must be judged against the natural climatic variability that occurs on a comparable time scale.  The Little Ice Age, Medieval Warm Period, and similar events are part of this natural variability.  These events correspond to global changes of 1 - 2 C.

4.  Global temperatures appear to be rising, irrespective of any human influence, as Earth continues to emerge from the Little Ice Age.  If the temperature increase during the past 130 years reflects recovery from the Little Ice Age, it is not unreasonable to expect the temperature to rise another 2 to 2.5 degrees Celsius to a level comparable to that of the Medieval Warm Period about 800 years ago.  The Holocene Epoch, as a whole, has been a remarkably stable period with few extremes of either rising or falling temperatures, as were common during Pleistocene glacial and interglacial periods.  Nevertheless, the Holocene has been, and still is, a time of fluctuating climate. 

5.  Climatic changes measured during the last 100 years are not unique or even unusual when compared with the frequency, rate, and magnitude of changes that have taken place since the beginning of the Holocene Epoch.  Recent fluctuations in temperature, both upward and downward, are well within the limits observed in nature prior to human influence.


6 comments:

  1. The use of historical data to reflect on current data is meaningless for CAGW as the causitive factors of warming of the CO2 narrative are different from those that brought us out of the LIA (and which are not known for certain).

    The really significant point here for CAGW discussion is this:
    If the temperature increase during the past 130 years reflects recovery from the Little Ice Age, it is not unreasonable to expect the temperature to rise another 2 to 2.5 degrees Celsius to a level comparable to that of the Medieval Warm Period about 800 years ago.

    Here the point is that the expected rise from the LIA has another 2.0 or so to go. The IPCC hypothesis is that the LIA recovery ended in the late 60s, so that perhaps only 10% of the subsequent warming is recovery these days. But how you determine that, I don't know. Either side.

    It is strange that the key process of recovery from the LIA is unknown or undecided. How can you say anything has ended when you don't know how it started?

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  2. Good points. Of course, the IPCC doesn't want to admit the Sun could control climate, most likely via amplifying mechanisms such as ozone & clouds, since that will shoot the CAGW meme in the foot.

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  3. Before you can accuse CO2, you must explain what caused the Medieval warm period to be warmer than now AND why that same cause is NOT the cause of our current warm period.

    Thanks
    JK

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    Replies
    1. Yes absolutely

      The IPCC says they can't model climate change without CO2, thus CO2 must be the cause.

      They conveniently leave out ocean oscillations and solar amplification via clouds and ozone, thereby leaving man-made CO2 as the only [false] cause.

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    2. "The IPCC says they can't model climate change without CO2, thus CO2 must be the cause." So the IPCC's approach is based on ignorance. Apparently something has been causing the world to change between ice age and interglacial periods and the cause cannot possible be man made CO2.

      Delete
  4. The link indicated that the paper was from 2002.

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