Historic High: Earth's Carbon Dioxide Levels Highest in 14 Million Years

In a study released in early December, it has been revealed that carbon dioxide levels in Earth's atmosphere have reached their highest point in human history. The study indicates that it has been approximately 14 million years since the Earth experienced such elevated levels of carbon dioxide (CO2), predating the existence of modern humans.

Lead author of the study, Bärbel Hönisch, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, highlighted that during the last occurrence of such high CO2 levels, Earth's temperature was up to 9 degrees Fahrenheit warmer than the present. Notably, this period predates the existence of the Greenland and West Antarctic ice sheets, and sea levels were likely more than 40 feet higher than today.

The study emphasizes the long-term sensitivity of the climate to greenhouse gases, with potential cascading effects evolving over millennia. CO2 levels, the primary greenhouse gas contributing to global warming, currently stand at 420 parts per million (ppm), compared to 280 ppm before the Industrial Revolution. Over this period, global temperatures have risen by approximately 2 degrees.

Co-author of the study, Gabriel Bowen from the University of Utah, warns that the planet has entered a range of conditions never before experienced by our species, emphasizing the urgency of addressing climate change and its long-term impacts.