A study finds that micrometeorites from 2.7 billion years ago, likely oxidized by CO2 in the atmosphere, may constrain the CO2 concentration in the Neoarchaean as being between 25-50% of the atmosphere at the time, which suggests that the nitrogen concentration was lower than present-day concentrations, allowing a modest greenhouse effect and cool climate consistent with evidence of Neoarchaean glaciation, according to the authors.
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Article #19-10698: "Oxidized micrometeorites suggest either high pCO2 or low pN2 during the Neoarchean," by Rebecca C. Payne, Don Brownlee, and James F. Kasting.
MEDIA CONTACT: Rebecca C. Payne, Pennsylvania State University, University Park, PA; e-mail: < rebeccapaynercp@gmail.com >
Proceedings of the National Academy of Sciences