New Paper Finds Effect of Human-Caused Carbon Emissions on Climate is "Non-Discernible"

Every now and then, a giant of modern science should be allowed to express himself in language that we all understand. In the informative Climate: The Movie, the 2022 Nobel physics laureate Dr. John Clauser thundered: “I assert there is no connection whatsoever between climate change and CO₂ – it’s all a crock of crap, in my opinion.” While not expressing himself in such forthright terms, the Greek scientist Professor Demetris Koutsoyiannis might agree. He recently published a paper that argues it is the recent expansion of a more productive biosphere that has led to increased CO₂ concentrations in the atmosphere and greening of the Earth. It is widely argued that changing atmospheric carbon isotopes prove that most if not all recent warming is caused by the 4% human contribution from burning hydrocarbons, but such anthropogenic involvement is dismissed by Koutsoyiannis as “non-discernible”. Koutsoyiannis is Professor Emeritus of Hydrology and Analysis of Hydrosystems at the National Technical University of Athens.

The isotope argument has been around for some time and has been useful in closing down debate on the role of human-caused CO₂ and its supposed effect in causing a ‘climate emergency’. The carbon in living matter has a slightly higher proportion of ¹²C isotopes, and recent lowering levels of ¹³C, which accounts for 99% of carbon in the atmosphere, are used to promote the idea that it is caused by burning hydrocarbons. But Koutsoyiannis argues that the more productive biosphere has resulted in “natural amplification of the carbon cycle due to increased temperature”. He suggests this may be a “primary factor for the decrease in the isotopic signature ¹³C in atmospheric CO₂”.

Clauser’s remarks, along with contributions from a number of other distinguished scientists, have led to widespread attempts to shadow-ban Martin Durkin’s Climate: The Movie in mainstream and social media. If Clauser and scientists like Koutsoyiannis are correct, there is no need for the Net Zero global collectivisation. Trillions of dollars can be taken back from the Climate Industrial Network to be used to solve more pressing environmental and social problems. In such circles, the idea that humans control the climate thermostat is regarded as little short of pseudoscience. In the film, the former Princeton professor William Happer says he can live with the descriptive suggestion “hoax”, although he prefers the word “scam”. Disregarding the role of natural forces and promoting a 50 year-old hypothesis – science speak for ‘opinion’ – that can’t even agree on the degree of warming caused by higher levels of CO₂ – holds little attraction for these sceptical science minds.

During the course of the Durkin film, the evidence mounts that the warming ‘opinion’ can’t explain any of the climate change observations seen over the last 500 million years of life on Earth. As the Daily Sceptic has noted on numerous occasions, it would help if there was at least one peer-reviewed paper that proved conclusively that humans caused all or most changes in the climate. A politically-manufactured ‘consensus’ and appeals to UN authority do not count.

Koutsoyiannis provides some of the historical background to the evolution of the isotope story, and its use to promote the ‘settled’ science narrative around CO₂. The generally accepted hypothesis “may reflect a dogmatic approach or a postmodern ideological effect, i.e., to blame everything on human actions”, he observes. Hence, he says, the null hypothesis that all observed changes are mostly natural has not seriously been investigated. To add weight to his contention, Koutsoyiannis repeats the infamous claim made recently at a World Economic Forum meeting by Melissa Fleming, Under Secretary-General for Global Communications at the United Nations: “We own the science, and we think that the world should know it.”

The Koutsoyiannis paper is long and detailed and he uses data obtained from the California-based Scripps Institute that has been measuring isotopic signatures since 1978, along with proxy data going back five centuries. The complex workings can be viewed in the full paper with the author concluding that instrumental carbon isotopic data of the last 40 years shows no discernible signs of human hydrocarbon CO₂ emissions. He also found that the modern record did not differ in terms of net isotopic signature of atmospheric CO₂ sources and sinks from the proxy data, including Antarctica ice cores, going back 500 years.

The lack, or otherwise, of a discernible human-caused carbon isotope signature is an interesting branch of climate science to investigate, although, as we have seen, it is constrained by the political requirements governing the settled science narrative. In 2022, three physics professors led by Kenneth Skrable from the University of Massachusetts broke ranks and examined the atmospheric trail left by the isotopes. They discovered that the amount of CO₂ released by hydrocarbon burning since 1750, “was much too low to be the cause of global warming”. The scientists found that claims of the dominance of anthropogenic fossil fuel in the isotope record had involved the “misuse” of statistics. They stated that the assumption that the increase in CO₂ is dominated by or equal to the anthropogenic component is “not settled science”.

They warned that “unsupported conclusions” of human involvement “have severe potential societal implications that press the need for very costly remedial actions that may be misdirected, presently unnecessary and ineffective in curbing global warming”.

Chris Morrison is the Daily Sceptic’s Environment Editor.