For years scientists have been warning of an apocalyptic future facing the world. With the prospect of an earth made infertile from over-production and mass reliance on chemicals, coupled with an atmosphere polluted by greenhouse gases there seems little to celebrate. But belief is growing that an answer to some of the earth’s problems are not only at hand, but under our feet. Specialists have just met in Perth to discuss the secrets of rock dust, a quarrying by-product that is at the heart of government-sponsored scientific trials and which, it is claimed, could revitalise barren soil and reverse climate change.