CO 2 -Forced Climate and Vegetation Instability During Late Paleozoic Deglaciation

Abstract

The late Paleozoic deglaciation is the vegetated Earth's only recorded icehouse-to-greenhouse transition, yet the climate dynamics remain enigmatic. By using the stable isotopic compositions of soil-formed minerals, fossil-plant matter, and shallow-water brachiopods, we estimated atmospheric partial pressure of carbon dioxide ( p CO 2 ) and tropical marine surface temperatures during this climate transition. Comparison to southern Gondwanan glacial records documents covariance between inferred shifts in p CO 2 , temperature, and ice volume consistent with greenhouse gas forcing of climate. Major restructuring of paleotropical flora in western Euramerica occurred in step with climate and p CO 2 shifts, illustrating the biotic impact associated with past CO 2 -forced turnover to a permanent ice-free world.