GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 36-26
Presentation Time: 9:00 AM-5:30 PM


LANDING, Ed, New York State Museum, 125 Manning Blvd., 222 Madison Ave., Albany, NY 12203, LIPPS, Jere H., Museum of Paleontology, University of California, Berkeley, CA 94720 and GEYER, Gerd, Institut für Geographie und Geologie, Universität Würzburg, Am Hubland, Würzburg, 97074, Germany

The dominant models for ancient and future global temperatures draw on Svante Arrhenius’ 1896 insights. He concluded CO2 was a key temperature driver and anticipated the modern climate catastrophe by calculating the effect of rising industrial CO2 emissions. The link from the late-19th century of rising temperature with ever higher pCO2 based on atmospheric and ice core samples substantiates his conclusions and illustrates warming by the greenhouse model. Greenhouse warming will accelerate with increasing pCO2 (ca. 2.5 ppm/yr, 340‒405 ppm over 1980‒2019) and feed-backs that increase greenhouse gas concentration (e.g., permafrost melting with CO2 and methane release, slowed CO2 storage by the biotic effects of oceanic acidification and drying-out of temperate forests, lower CO2 uptake by warming oceans). Arrhenius showed the marginal radiative forcing of CO2 was highest at 200 ppm, fell at higher pressures, with the “warming effect” effectively capped at 1,000 ppm―a value likely reached in less than 200 years with feedbacks and humanity’s uncertain response. But, the warming rate will increase as non-greenhouse factors will come to dominate Earth’s temperature by lowering of its albedo (reflectivity). Thus, melting of ca. 50% of reflective Arctic Ocean pack ice over 30 yr has increased global warming rate by ca. 25 %―a rate that will accelerate with complete global ice loss. Ice melt accelerates the eustatic rise rate by 3.1 mm/yr. over each previous year, with heat absorbing and higher insolation water ultimately covering ca. 15% of the more reflective land. An adequate global temperature model must incorporate 1) analysis that shows Phanerozoic temperatures independent/slightly negatively correlated with the very high pCO2 values of the GEOCARB model (levels sometimes incompatible with terrestrial metazoans and many embryophytes), 2) the rapid pCO2 fall in the Devonian with no significant temperature decrease, and 3) the lower “warming effect” above 1,000 ppm. Global temperature models must include non-greenhouse (i.e., hyperwarming) factors as changed albedo with eustatic rise/fall and ice loss/growth, lower vs higher latitude continent distributions, and presence of a polar continent/restricted polar ocean.