G'day all,

Personal Aside: Everyone does know I'm Australian, right? And I really do say "G'day" normally just like Steve Irwin

Summary:
  • Carbon Dioxide in ice cores dubious science
  • Ice Cores good for many things eg Volcanic Activity
  • Ice Cores vary wildely even when drilled on top of one another
  • Does not mean ice cores do not show anything about carbon dioxide.
  • Conclusion: No paradox in using ice core estimates of previous carbon dioxide plus stating ice cores not good for just that.
  • Why: Because trends and specific measurements are different



Yet another personal aside: Now what do I write. Maybe the summary is a bit too detailed. Have to fine tune this process.

Introduction
Blacknad finds it paradoxical that dehammer can dispute the validity of ice core samples in establishing carbon dioxide levels while using the very same ice cores to argue about paleo-historic carbon dioxide levels.

I agree with dehammer and do not believe there is any paradox.

Main Argument
Ice cores have many uses that they are well suited to. They were originally dug up because of interest in changes in snowfall and the amount of accumulation despite melts as well as to look at such things as volcanic activity. They contain many isotopes of substances that can be used to calculate something of value to science. The most recent example I came across is in determining the magnetic field strength of the sun.

There are physics studies that have suggested that ice cores do not make a good source for determining carbon dioxide in the atmosphere. (Sorry no links to back this up).

I, and others that I have read, have grave concerns that ice cores actually trap representative samples of historic atmosphere. For carbon dioxide the ice core itself is not being studied. Little bubbles of trapped gasses are. To those that use ice core studies for temperature or carbon dioxide levels, it is assumed that the bubbles are representative samples of the atmosphere at the time that the ice was laid down; that no contamination occurs during the drilling or any of the other processes before the tiny bubbles are extracted; that the trapped bubbles are completely sealed and that no modification to the contents of the bubble or leaching in or out of the bubble occurs during its time in the ice core.

So there is cause for concern about ice cores and carbon dioxide readings both in the physics used in doing the calculation and also because the assumption that the sample is representative of the carbon dioxide in the atmosphere at the time of being trapped seems to be a very big assumption. Further, laboratory tests on carbon dioxide levels in bubbles when frozen in ice do not support the theory.

However, just because the process is suspect and accuracy is a big issue, does not mean that nothing can be learned about carbon dioxide in the historic atmosphere. However poor, the methodology may be, it is all there is until someone finds something else.

The proof to all this is in any study of carbon dioxide levels where more than one core is drilled. The results really are massivily different. But while the amounts are different, the trend is not. You can tell that carbon dioxide has risen or fallen and even that it has been much higher in the past as well as lower. But what you cannot tell is by how much.

So saying that there was 210.2 ppm or even 210 plus or minus 20 ppm CO2 in 1810 is just not backed up by good physics. However saying, the CO2 levels were a bit lower in 1810 than in 1900 probably is reasonable.


Regards


Richard

Sane=fits in. Unreasonable=world needs to fit to him. All Progress requires unreasonableness