Impact of anthropogenic CO2 on the next glacial cycle

Abstract

The model of Paillard and Parrenin (Earth Planet Sci Lett 227(3-4):263-271, 2004) has been recently optimized for the last eight glacial cycles, leading to two different relaxation models with model-data correlations between 0.8 and 0.9 (García-Olivares and Herrero (Clim Dyn 1-25, 2012b)). These two models are here used to predict the effect of an anthropogenic CO2 pulse on the evolution of atmospheric CO2, global ice volume and Antarctic ice cover during the next 300 kyr. The initial atmospheric CO2 condition is obtained after a critical data analysis that sets 1300 Gt as the most realistic carbon Ultimate Recoverable Resources (URR), with the help of a global compartmental model to determine the carbon transfer function to the atmosphere. The next 20 kyr will have an abnormally high greenhouse effect which, according to the CO2 values, will lengthen the present interglacial by some 25 to 33 kyr. This is because the perturbation of the current interglacial will lead to a delay in the future advance of the ice sheet on the Antarctic shelf, causing that the relative maximum of boreal insolation found 65 kyr after present (AP) will not affect the developing glaciation. Instead, it will be the following insolation peak, about 110 kyr AP, which will find an appropriate climatic state to trigger the next deglaciation. © 2013 Springer Science+Business Media Dordrecht