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. --- 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: xitter.cf/Ceist8/status/18368981…