Southern Ocean dust–climate coupling over the past four million years

Dust plays a central part in ocean biogeochemical cycles by supplying iron and other essential micronutrients to regions where marine productivity is limited by the availability of iron. Martínez-Garcia et al. present a marine record of dust and iron supply to the Southern Ocean during the past four million years. The data, derived from leaf waxes, establish that previous records of dust flux from Antarctic ice cores are broadly representative of a larger area. Importantly, the dust and iron supply rose sharply 1.25 million years ago, suggesting that increased dust supply may be a major influence on the more severe swings between the glacial and interglacial climate of the late Pleistocene.