So if the CO2 levels were high 250 million years ago, during the 800,000-year long ice age, that would again show that the CO2 concentration is not a driving mechanism, and if CO2 levels were low during the Permian-Triassic Boundary, that would also show that CO2 co...
They found that the amount of CO2was roughly equivalent to the levels that have been predicted for the 21st century. They suggest that a single pulse produced by an eruption would have pumped enough CO2into the atmosphere to raise global temperatures by an average of 2 degrees Celsius. One er...
Using ice cores drilled in Greenland and Antarctica, scientists havea pretty good recordof how the composition of Earth’s atmosphere has fluctuated over the last 800,000 years. That’s why scientists know carbon dioxide levels are higher than they’ve ever been in that amount of time. Last ...
Other proxies demonstrated that many millions of years ago, CO2 levels in the atmosphere reached, at various times, 377 ppmv, 450 ppmv, and even 3,000 ppmv (Kurschner et al. 1996, Royer et al. 2001), and that during the past 10,000 years Courtesy of Zbigniew Jaworowski these levels ...
The Piacenzian stage of the Pliocene (2.6 to 3.6 Ma) is the most recent past interval of sustained global warmth with mean global temperatures markedly higher (by ~2–3 °C) than today. Quantifying CO2 levels during the mid-Piacenzian Warm Period (
Dr. Gerald Marsh tells us that five hundred million years ago, carbon dioxide concentrations were over 13 times current levels; and not until about 20 million years ago did carbon dioxide levels drop to a little less than twice what they are today.[1]Since 1750 the concentration in the air...
d Reconstructed early Pleistocene pCO2 (median levels of pCO2 distributions, 2.6–0.8 Ma) and ice core CO2 record (0.8–0 Ma)36. Horizontal gray line shows the pre-industrial pCO2 level (280 ppm). Errors associated with δ13Cc and δ13CSOM are standard deviations of all ...
and then CO2levels fell below those levels in the Hirnantian Glaciation (Ice Age), 445 million years ago (Pancost et al. 2013). The continents wereconfigured very differentlythen, and the sun was about4% less bright, allowing an ice age at higher CO2levels than possible today (Scotese 2021...
During the Pliocene Epoch, some 3 million years ago, when global temperatures were estimated 2-3 degrees Celsius warmer than today, CO2 levels are believed to have topped out somewhere between 310 to 400 ppm. Atmospheric carbon dioxide levels are at their highest point in over 800,000 years...
During the Middle Miocene, when temperatures were ∼3° to 6°C warmer and sea level was 25 to 40 meters higher than at present, pCO2 appears to have been similar to modern levels. Decreases in pCO2 were apparently synchronous with major episodes of glacial expansion during the Middle ...