The simulations of the end‐Cretaceous climate and the effects of the impact are carried out with a coupled climate model consisting of a modified version of the ocean general circulation model MOM3, a dynamic/thermodynamic sea ice model, and a fast statistical‐dynamical atmosphere model. Our impact simulations are based on a climate simulation of the end‐Cretaceous climate state using a Maastrichtian (70 Ma) continental configuration. The solar constant is scaled to 1354 W/m2, based on the present‐day solar constant of 1361 W/m2 and a standard solar model. A baseline simulation with 500 ppm of atmospheric CO2 and a sensitivity experiment at 1000 ppm CO2 concentration. The impact is assumed to release 100 Gt sulfur and 1400 Gt CO2. We simulate stratospheric residence times of 2.1 y, 4.3 y and 10.6 y. More information about the model can be found in the manuscript (https://doi.org/10.1002/2016GL072241).

The data is model output from the coupled ocean-atmosphere model CLIMBER3alpha which models climate globally on a 3.75°x3.75° (ocean) and 22.5° (longitude) x 7.5° (latitude) (atmosphere) grid.