Could such variations occur not only in glacial times, but also in warm periods like the present? (history.aip.org)
By extrapolating from its radiative forcing in the current climate, we estimate that dust reduces precipitation during glacial times by as much as half the reduction due to the colder climate alone. (pubs.giss.nasa.gov)
A comparison of this result with the observed pCO2 anomaly (42) and the residual from subtraction of this result from the anomaly shows that the lowest pCO2 values during the coldest glacial times stem from the dust − climate feedbacks considered here (Fig. 5A). (pnas.org)