The claim that “CO₂ always lags temperature” is a myth based on local Antarctic ice-core data, not global climate reconstructions.
This misconception was popularised by fossil-fuel propaganda such as the polemic film The Great Global Warming Swindle, which misrepresented the research of Nicolas Caillon et al. (2003).
The film cherry-picked a single Antarctic deglaciation event while ignoring the broader climate context and even the paper’s own conclusion:
“Finally, the situation at Termination III differs from the recent anthropogenic CO₂ increase.”
science.org/doi/full/10.1126…
In glacial cycles, small changes in Earth’s orbit (Milankovitch cycles) initially warmed parts of the Southern Hemisphere. That warming caused the oceans to release CO₂, which then spread through the atmosphere and amplified warming globally.
When global temperature reconstructions are examined instead of a single Antarctic record, the picture changes completely.
"Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation" -Shakun et al. (2012)
"the small apparent lead of Antarctic temperature over CO₂in the ice core records does not apply to global temperature."
nature.com/articles/nature10…
Their global reconstruction found that CO₂ increases PRECEDED about 93% of the total global warming during the last deglaciation.
In other words:
Antarctica warmed first locally due to orbital forcing, but rising CO₂ drove most of the subsequent global warming.
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Earth’s geological history confirms that atmospheric CO₂ has been a major DRIVER of global temperature for hundreds of millions of years.
Multiple independent paleoclimate reconstructions consistently find a strong coupling between CO₂ levels and global temperature:
“Atmospheric CO₂ exerts a dominant control on GMST, both today and in the geologic past.” -Judd et al. (2024)
“CO₂ is a greenhouse gas that has played an important, if not the predominant role, in regulating Earth’s temperature through time.” - Scotese et al. (2021/2022)
“The concentration of atmospheric carbon dioxide is a fundamental driver of climate.” - Cenozoic CO2 Proxy Integration Project (2023)
“CO₂ and climate are coupled throughout the past 66 million years.” -Rae et al. (2021)
“We find a strong relationship between CO₂ forcing and temperature from the proxy data.” -Mills et al. (2019)
“The evolution of Earth’s climate on geological timescales is largely driven by variations in solar irradiance and changes in greenhouse gas concentrations.” -Foster et al. (2017)
“CO₂ as a primary driver of Phanerozoic climate.” Royer et al (2004)
“CO₂-forced climate thresholds during the Phanerozoic.” -Royer (2006)
“There is indeed a correlation between CO₂ and paleotemperature, as manifested by the atmospheric greenhouse effect.” -Berner et al. (2001)
Across multiple geological timescales, from the last deglaciation to the entire 540-million-year Phanerozoic, the scientific literature consistently finds that CO₂ and temperature are strongly linked.
Claims that CO₂ cannot drive climate because it “lags temperature” in Antarctic ice cores ignore this enormous body of paleoclimate evidence.
See links to papers in this thread:
x.com/Ceist8/status/18368981…
New paper on Earth's global mean temperature & CO2 levels for the last 485 million years.
"A 485-million-year history of Earth’s surface temperature" Judd et al 2024
science.org/doi/10.1126/scie…
"Atmospheric CO2 exerts a dominant control on GMST, both today and in the geologic past"