Well then this should turn you into a skeptic. https://www.researchgate.net/publication/383240024_Multivariate_Analysis_Rejects_the_Theory_of_Human-caused_Atmospheric_Carbon_Dioxide_Increase_The_Sea_Surface_Temperature_Rules

Sea Surface temps are driving the increase in c12.

I suppose you haven't seen this https://www.ox.ac.uk/news/2023-10-04-new-research-finds-ancient-carbon-rocks-releases-much-carbon-dioxide-worlds which showed that rocks outgas as much carbon dioxide as volcanoes. This wasn't included in the climate models but is undoubtedly part of the reason atmospheric CO2 has been rising (we are no longer pumping as much sulfur into the atmosphere and thus the rocks are now in release mode rather than absorption mode when a lot of acid was coming down with rain - a rain that no longer falls in many places as clouds have declined and there has been no major increase in precipitation, especially over land. Most of these surface rocks contain lighter carbon - the kind being blamed for the isotope balance issue.

And then there is this. https://www.pnas.org/doi/pdf/10.1073/pnas.1619240114

" Using updated records, we show that no plausible

combination of sources and sinks of CO2 from fossil fuel, land,

and oceans can explain the observed 13C-Suess effect unless an

increase has occurred in the 13C/12C isotopic discrimination of land

photosynthesis. "

end

In other words there is something equally wrong with the isotope argument. There are other forces at work.

Here's more:

"Fossil fuels are slightly depleted in 13C because they were initially formed from photo

synthesis, which involves isotopic discrimination, that is, selective

uptake of 12CO2 over 13CO2. The emission of fossil fuel CO2

therefore lowers the atmospheric 13C/12C ratio. A second im

portant influence on the 13C-Suess effect is the natural back-and

forth exchanges of CO2 with land and ocean carbon reservoirs.

These gross exchanges, also known as "disequilibrium fluxes,”

scramble carbon atoms between reservoirs, thereby spreading

the Suess effect into the land and oceans while reducing the

atmospheric signal. A third influence is net gain or loss of carbon

by the land biosphere, which is depleted in 13C because of

photosynthesis, similar to fossil fuels. A sink for excess CO2 on

land therefore offsets the influence of fossil fuel burning, not just

on CO2amount, but also on its isotopic composition. In contrast,

ocean uptake of excess CO2 has little influence on δ13C of atmospheric CO2 ."

end

Just to make sure you understand the PLANTS are taking more c13 out of the atmosphere. Get it?

And just one percent of the atmospheric carbon dioxide is c13. So that is 0.0045% of the total volume of the atmosphere. It is so insignificant amount we cannot say with any certainty just how much is there at any given time.

BTW here is a list of 700 papers that dispute the orthodoxy on climate change, putting the lie to Oreskes and the 99% claim. https://www.cfact.org/2010/04/26/700-papers-supporting-climate-realism/

And it wouldn't do anything if we did reduce emissions. https://www.nature.com/articles/s41467-026-68586-y

So your strongest argument is in doubt, and all the other things predicted by the alarmists have been tarnished if not downright disproven. It's time to take a good, hard look at the science in opposition to the hypothesis.