From NoTricksZone

By Kenneth Richard 

Reconstructions of paleo CO2 levels openly rely on data derived from plant stomata. But when modern (1800s-present) CO2 measurements from stomata conflict with the narrative that humans drive CO2 levels, they are patently rejected.

Scientists readily acknowledge plant stomata evidence from one location are “widely used as an effective tool for paleoenvironmental reconstructions” of global atmospheric CO2 from 1 to 150 million years ago (Badihagh et al., 2024).

For example, in a new study, 100-150 million-year-old stomata samples from Iran are shown to re-confirm global atmospheric CO2 levels hit 1,100 to 1,700 ppm during the Jurassic period. The authors proudly showcase how consistently their stomata-derived CO2 measurements compare to several other reconstructions reaching the same conclusion about past CO2 concentrations.

But that’s where the stomata-are-an-effective-paleo-CO2-measuring-tool perspective stops.

Whereas millions of years ago CO2 data derived from stomata were thought to be accurate, direct stomata measurements recorded in scientific papers from only a century ago – even the 1940s and 1950s – are regarded as not accurate. They must be rejected.

Dr. Ernst-Georg Beck’s compiled research with plant stomata-derived CO2 measurements was posthumously published in 2022. It’s an exhaustively-referenced paper detailing 97,404 direct near-ground measurement from 901 stations situated across the world, in both hemispheres. (This is very much unlike the ice core CO2 record in which only one continental location, Antarctica, is used; and yet this local record – contradicted by Greenland ice cores – is regarded as “global”.)

The research was recorded in 292 scientific papers (77 authors) covering stomata-derived direct CO2 measurements for the industrial era, 1800-1960.

These database compilations – ~60,000 global-scale measurements between the 1930s and 1950s alone – consistently show CO2 hit 380 ppm in 1943 and 372 ppm in 1950, with very small error margins after about 1870.

The currently accepted CO2 values for 1943 and 1950 are instead recorded as 310 ppm, and the 372 to 380 ppm values are not assumed to have been achieved until the mid-2000s. A data-driven portrayal of a decadal-scale decline in CO2 after the 1940s peak (shown in Fig. 24) contradicts the viewpoint that sharply rising anthropogenic CO2 emissions after 1945 led to tandemly increasing CO2 concentrations. Consequently, these direct CO2 measurements – tens of thousands of them from across the world – are rejected by the gatekeepers of the humans-did-it narrative.

Further, the stomata-derived CO2 values also indicate the temperature is the leading factor determining the CO2 concentration, with the CO2 changes correlationally (r = 0.67) lagging the temperature changes by about a year. This once again conflicts with the conclusion that CO2 levels are determined by anthropogenic emissions.

Another stomatal CO2 study published nearly 20 years ago also documents ±100 ppm CO2 changes over the last few centuries, with a peak of about 380 ppm in the 1940s. Like Beck’s work, this too must be rejected, as it doesn’t align with the human-caused angle.