MODELLED CLIMATIC EFFECTS FROM DECCAN TRAPS CO2 RELEASE
We modified and employed a zero-dimensional carbon cycle model, GEOCYC, itself a modification on an earlier GEOCARB III model. CO2 emissions from short (1-100 year) individual eruptive events are unlikely to lead to substantial warming , in contrast to SO2 aerosols which, while not modelled here, may have measureable to severe cooling effects during active emission (Self et al., 2015). Previously, the warming effects of flood basalt carbon emissions have been disregarded due to the length of time between emissions, but our results suggest that despite the episodic nature of flood basalt eruptions, the long lifetime of CO2 causes it to accumulate in the atmosphere and contribute to a global increase in temperature. We modelled a number of emissions scenarios and found that the details of the timing, frequency, and duration of individual eruptions did not materially alter the results, and the overall duration of volcanic activity and total emitted volumes of CO2 are the primary controls on overall warming. Given a range of different published estimates of CO2 release from the DTVP and constraints on its eruptive duration, the eruption the Deccan Traps is capable of generating measurable and significant global warming (~3° or more) in some scenarios, but would have a negligible effect in others.