In this episode I am returning to a topic that has become a favourite for pundits and trolls, and that is carbon dioxide. The near doubling of the atmospheric concentration of this colourless odourless gas has been identified by scientists as contributing to an accelerating heating of the biosphere that has significantly affected the climate.  As a by-product of one of our most lucrative industries, the burning of fossil fuels, CO2 has gained a lot of friends.  And because of that it is the subject of a targeted disinformation campaign, becoming headline political news.  This is a job for The Rational View. Bärbel Hönisch grew up in Germany and studied at the Universities of Bielefeld and Bremen, as well as the Alfred-Wegener-Institute for Polar and Marine Research in Bremerhaven. She received her Diploma in Biology in 1999 and her PhD in Natural Sciences in 2002. After moving to the US, she held academic positions at the Lamont-Doherty Earth Observatory of Columbia University, the City University of New York at Queens College, the State University of New York in Stony Brook, and Bremen University. She joined the faculty of the Department of Earth and Environmental Sciences at Columbia University in 2007. She is interested in the effect of global carbon cycle perturbations on climate and the oceans, in particular past variations of seawater acidity and its relation to atmospheric CO2. As she was originally trained as a marine biologist, her research includes culture experiments with living marine calcifiers to validate proxies for past environmental conditions. She applies the resulting calibrations to reconstructing seawater carbonate chemistry and atmospheric CO2 variations through Earth history. Over the past 7 years she has led a consortium of paleo-CO2 proxy experts to compile, vet and modernize published paleo-CO2 estimates over the Cenozoic. Support the podcast at https://Patron.podbean.com/TheRationalView Facebook @TheRationalView Twitter @AlScottRational