Chapter 7

The Great Misunderstanding

 

In his video, Al Gore claims the climate chart he presented was the results obtained by analyzing the Oxygen Isotope bubbles trapped in ice from the Antarctic.  In his book of the same name, “an inconvenient truth”, published in 2006 this climate chart is not shown.  This is the same climate chart I was able to duplicate by modifying my own data as in the last chapter. 

 

I might speculate that it was left out of the book because his scientific advisors have identified the same weakness in his data that I identified; namely that taken back further in time his data would produce a many lobed 5th Glacial Advance, joining it together with five previous Glacial Advances to produce a single glacial advance.  Such a glacial advance is not supported by the Geological evidence that clearly separates the two most recent of these previous glacial advances from each other and from it.

 

On her website, http://ethomas.web.wesleyan.edu/ees123/isotope.htm, Dr. Ellen Thomas has placed a 9 page paper entitled “The Behavior of isotopes of hydrogen and oxygen: heavy and light rain”.   Dr. Thomas currently holds the position of Senior Research Scientist, Center for Study of Global Change, Department of Geology and Geophysics, Yale University, New Haven CT, USA.  In her paper she describes all the isotopes of Hydrogen and Oxygen including the very rare third isotope of Oxygen, 17O that I did not include in my discussion at the beginning of this book.

 

Dr. Ellen Thomas also studies Benthic Foraminifera which differ from the many Planktic species that live in the surface waters I described earlier.  All the many benthic species live in the ocean depths.  Incidentally, the Foraminifera climate plot I used is comprised of data obtained from both Planktic and Benthic species of foraminifera. I only described how the Planktic varieties reflect climate change as that is the easiest for a lay person to understand. 

 

I believe the Oxygen Isotope measurements taken from Foraminifera are more accurate than those taken from ice bubbles because 1) there are less inherent assumptions regarding the source of the Oxygen Isotope 2) all of the isotopes of Hydrogen were eliminated from the water from which the oxygen samples were obtained at the time when the oxygen carrying Calcium Carbonate was formed by the foraminifera. 3) Once incorporated in the CaCO3 the oxygen isotope is much less subject to any further climate changes. 4) The temperature of the waters that both kinds of foraminifera can survive in is well known which makes it possible to establish a realistic baseline for the temperature variations found.

The latest 750,000 years of my data also incorporates data collected from Oxygen Isotope measurements taken from polar ice corrected to agree with the foraminifera data from the same time span.

 

This was done because the foraminifera record is more accurate in temperature levels but less responsive time-wise, - so that the ice core samples have a finer resolution.  By correcting the baseline temperature level of the ice-core samples to agree with the more accurate (and lower) baseline temperature level of the seabed samples we end up with the best of both methods.  This is particularly justifiable considering the fact that the results are in agreement with the other geological evidence that has nothing to do with temperature, such as the extent and timing of the glacial advances as determined by glacial tills etc.

 

The Gore team has chosen not to adjust the baseline temperature level of their ice core measurements to agree with other methods.  Perhaps because they want to report the higher temperatures they get from using this method.

 

Dr. Thomas found in taking ice core measurements by the Oxygen Isotope method in Greenland, her results were 15oC different than her Nitrogen Isotope measurements of the same ice core.  Using the “Cold Turkey” method of direct temperature measurement taken from the same ice core confirmed the Nitrogen Isotope measurements were more reliable.4 Unfortunately, Dr. Thomas did not say which temperature measurement was higher.

 

Oxygen Isotope measurements of ice core samples do not handle high temperatures very well.  This is due to the fact that the separation (fractionation) of both the Hydrogen Isotopes and the Oxygen Isotopes found in water by means of evaporation and condensation (equilibrium fractionation) only occurs at lower temperatures than those found at the equator and the lower to mid tropics.

 

Global temperatures are not correlated with equilibrium fractionation temperatures but rather with the amount of Rayleigh Fractionation which depends on the number of repeated equilibrium fractionation events that occur while water evaporated at the equator passes over the mid and higher latitudes.  The more equilibrium fractionation events that occur while the water vapour runs this gauntlet from the equator to the poles, the more the final condensate (Polar ice) will be rarified in the heavier isotopes of both hydrogen and oxygen.  Thus a Colder climate will leave very few heavier isotopes of hydrogen and oxygen in the ice as compared with the number of these heavier isotopes found in the ice of a hotter climate.

 

 In Appendix IV, I have detailed Dr. Thomas’s description of measuring the Oxygen Isotope concentrations in the polar ice caps along with my comments as to how the basic assumptions are not necessarily so - and how large quantities of fresh water evaporate from the North Temperate Zone added to a later stage in the Rayleigh Fractionation could skew the expected results so that the actual results obtained in the northern polar ice would have the observed elevated baseline.

 

Briefly, the assumption made is that all the ice at the poles is from ocean water that was evaporated at or near the equator.  Most of Northern Canada is like a vast shallow fresh water ocean dotted with many islands.  Because this water is not as deep as the salt water oceans it can be expected to evaporate quicker, and it will also evaporate at a lower temperature than the salt waters because it contains much less solute.  Thus the polar ice is not only composed of water that was evaporated at or near the equator, but also of fresh water that was evaporated from the temperate zones.  In order to determine the isotopic composition of polar ice, the ice is compared to the isotopic composition from a standard water sample taken from the salt water ocean called SMOW for Standard Mean Ocean Water.

 

If this fresh water source is composed of rain water, it will contain many heavier isotopes of both Oxygen and Hydrogen that fell out of an earlier fractionation so that when it is re-vaporized at a later stage in the Rayleigh Fractionation it adds its heavier isotopic composition to the water vapour that makes it to the pole.  We might also expect a little re-vaporization of glacial melt-water from further north containing less of the heavier isotopes in its isotopic composition, but the amount of this re-vaporization is likely much less than the re-vaporization from the mid and Southern portions of the Temperate zone where it is hotter and more re-vaporization is likely to occur.

 

This applies to both hemispheres, and the fresh water evaporate that makes it to the South Pole need not all come from the South Temperate Zone, some of it could come from the South Tropical Zone as well.  When the polar ice is compared with SMOW it will be found that there are many heavier isotopes, so a hotter climate is indicated.  The net effect is an elevated baseline.

 

OK, I have now determined the likely cause for Al Gore’s elevated baseline in his plot of the climate record over the past 650,000 years. 

 

It is time to look at Al Gore’s claim that the extra (none existent) global heat comes from the greenhouse heating effect: