Extended Data Figure 5 : Key results of sensitivity experiments.

From: Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum

Extended Data Figure 5

The figure shows the influence of uncertainties in the CIE onset duration on diagnosed total carbon release. For these idealized experiments, the CIE onset phase was assumed to occur linearly, with the decline in ocean surface dissolved inorganic carbon (DIC) δ13C (by 3.5‰) and pH (by 0.3 pH units) having a duration (Δτonset) that varied from 100 to 20,000 years; thereafter, the target pH and δ13C values were held constant until the end of the experiment (at 50,000 years). ah, The evolution with time of these target ocean surface variables, with pH on the left-hand y axis, and δ13C(DIC) on the right-hand axis. ip, Maximum carbon emission rate per time interval. qx, Cumulative carbon emission per time interval in Eg of carbon. y, z, aaaf, Average emitted δ13C per time interval.