Drought and subsequent re-wetting could destabilize peatland carbon stores, according to a study published online this week in Nature Geoscience. Peatlands store vast amounts of carbon due to the water-saturated conditions, which prevent decay and the release of this carbon to the atmosphere. Nathalie Fenner and colleagues examine the impact of drought on peatland carbon loss in a series of laboratory and field experiments. They show that drought stimulates the growth of microbes and the concomitant breakdown of organic matter and release of carbon dioxide. Subsequent re-wetting of the peat exacerbates the release of carbon dioxide, due to drought-induced increases in nutrient and labile carbon levels.