Reproducing the Mid-Piacenzian Warm Period Climate in the 2020s.

Abstract

The current expectation of climatologists is that levels of atmospheric carbon dioxide (CO2) and other greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), will correspond, in the 2020s, to an increase in mean annual global near-surface atmospheric temperature of less than 1.5°C above the pre-industrial Holocene norm (1750 baseline; atmospheric CO2 = 278 ppm). This paper will argue, contrarily, that it is not possible to reproduce the atmospheric chemistry of the Mid-Piacenzian Warm Period (3.3-3 Mya) of the Pliocene Epoch, 5.3-2.588 Mya, without also reproducing its climate, and that – consequently – we can expect to see global warming of 3°C this decade.