a Dark orange line with yellow shaded area shows an evolving ‘fire suppression ratio’, representative of the changing fuel source due to angiosperm evolution. The yellow shaded area indicates how uncertain the evolutionary changes in the fire regime are and how this is propagated to the model results. The size of the uncertainty window represents the suppression ratio of the previous and next evolutionary stages. Black dashed line shows fixed weak fire feedback in the baseline COPSE model. b Modelled land-derived organic carbon burial. C Modelled atmospheric oxygen mixing ratio compared to inertinite-derived estimates from ref. 47 as blue bars.