![]() ![]() ![]() We used those two state-of-the-art methods, analyzed how they compare with each other, and looked at what history they inform us about for the last 66 million years.” “And in particular, these two-ocean marine-based methods are the two most common and arguably the most accurate. “Societally, we all care about carbon dioxide in the atmosphere, and in paleoclimatology we have these methods to look at CO 2 variations in Earth’s history,” Zhang said. Understanding Ancient Atmosphere Using Tiny Ocean Organisms “In the last 100 years, fossil fuel burning has driven CO 2 from 280 up to 414 ppm,” he said. Andrews.įor the last one million years, CO 2 levels slowly oscillated between 180 ppm and 300 ppm, as Earth’s climate transitioned in and out of the ice ages, with the dawn of agriculture and human settlement only establishing when CO 2 and climate stabilized at the end of the last ice age, around 10,000 years ago, Rae said. “For instance, at CO 2 levels of around 1500 ppm, last seen about 50 million years ago, it was so warm that we find fossilized alligators in the Arctic,” said James Rae, lead author of the paper and reader in the School of Earth and Environmental Sciences at the University of St. The study found CO 2 levels of more 1500 parts per million (ppm) in the atmosphere associated with extreme global warmth 50 million years ago, a climate so warm that no ice existed on the poles, the researchers said. This new environmental reconstruction research shows that 21st century carbon emissions have the potential to return atmospheric carbon dioxide (CO 2) to levels not seen since the much warmer climates of Earth’s distant past. In a new study, scientists have estimated carbon dioxide levels from the past 66 million years using two methods analyzing tiny organisms found in sediment cores from the deep seafloor, and found a consistent picture of the evolution of the ocean-atmosphere carbon dioxide levels.Ĭo-authored by Yige Zhang, assistant professor in the Department of Oceanography at Texas A&M University, and oceanography graduate student Xiaoqing Liu, the research was conducted by an international team and recently published in the Annual Review of Earth and Planetary Sciences. ![]()
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