New study: CO2 levels at least equivalent to today’s level of approximately 420 ppm would have been necessary 10,000 years ago.
Germany’s online Report24 posted an article titled: “Why Ice Cores Lie: High CO2 Levels Characterized Early Times“.
The article summarizes the study by Frans J. Schrijver titled “Historical CO2 Levels in periods of global Greening” which NTZ’s author Kenneth Richard posted here.
The Report24 article questions the traditional measurements of CO2 values from ice cores, which suggest levels of about 280 ppm (parts per million) for the early Holocene (10,000 years ago).
The recent study by Schrijver argues that the Earth was significantly greener 10,000 years ago, with a forest area over 50 percent higher than today. To enable such growth, CO2 levels at least equivalent to today’s level of approximately 420 ppm would have been necessary. This is justified using the Mitscherlich Law, which describes the relationship between CO2 fertilization and plant growth.
It is claimed that the Earth itself has quadrupled its natural CO2 emissions since 1750 (from 166 to 210 gigatonnes of carbon per year). In comparison, the human contribution is said to be tiny, increasing from 0 to 11 gigatonnes.
The article concludes that the idea of low historical CO2 levels and a dramatic, human-caused increase is untenable. The Earth was already green in early times and CO2 levels were high, with practically no human influence.
Quadrupled? Really?
Faculty of Economics and Management.
https://europeanconservative.com/articles/commentary/climate-misinformation-think-wrongly-pay-dearly/
[…] New Study Suggests Ice Cores Are Wrong … CO2 Levels Were High In Early Holocene — No Tricks Zone […]
I have a theory as to why ice core CO2 values might be lower than what was actually in the air at the time the snow fell.
When a snowflake forms, water goes from being a gas, water vapour, to being a solid, ice, without passing through the liquid state. CO2 is very soluble in liquid water but not so much in ice. Because of this, there is very little CO2 dissolved in the solid water crystals known as a snowflake.
Snow falling on the icecap builds up, trapping air, containing CO2, in gaps in between the snowflakes. The top layers of the ice above the compressed ice pack is known as the firn.
Almost every year, sometimes more than once, a warm wind from the direction of the tropics, warms the top of the firn enough for some of the snow to melt. This liquid water seeps down through the gaps in the snow, to refreeze a bit lower in the firn.
Now here is my theory. As the liquid water seeps downward, CO2 in the air gaps will dissolve in that water, reducing the concentration of the CO2 left behind in the air bubbles.
When the scientists drills an ice core many years later and test the CO2 content of the air bubbles, they find the concentration to be lower that in the air above.
This is a testable theory. If I am right there should be a concentration gradient of CO2 dissolved in the very top layers of ice in the firn. The concentration of CO2 dissolved in the snow on the top should be lower than the concentration in ice lower down.
This would explain the findings of this study. Ice core data is being used to claim that the concentration of atmospheric CO2 is higher now than at any time in the last several hundred thousand years. However, this is only true if the concentration in the air bubbles in the ice is the same as was in the air when the snow fell.
We know that temperature leads CO2 because the CO2 comes from the oceans by Henry’s Law. The ice cores had to be wrong, thus this paper is really interesting. (I have not read it yet)