Dust is all that's needed to plunge the world into an ice age. When blown into the sea, the iron it contains can fertilise plankton growth on a scale large enough to cause global temperatures to drop. The finding adds support to the idea of staving off climate change by simulating the effects of dust - perhaps by sprinkling the oceans with iron filings.
Some claim climate change will destroy our species; now it seems it also helped forge it. The rapid fluctuations in temperature that characterised the global climate between 2 and 3 million years ago coincided with a golden age in human evolution.