New research reveals how soil bacteria build the only known enzyme for the destruction of the potent global warming and ozone-depleting gas nitrous oxide. Alongside carbon dioxide (CO2) and methane, the greenhouse gas nitrous oxide (N2O), commonly known as ‘laughing gas’, is now a cause for great concern, and there is much international focus on reducing emissions. It is hoped that the findings will help pave the way for strategies to mitigate the damaging effects of N2O.