Billions of people owe their lives to our ability to grab nitrogen out of the air to fertilise our crops. But there can be too much of a good thing, reports Kira Weissman In Short The Haber-Bosch process allows us to 'fix' nitrogen from the air, but tipping the nitrogen balance has environmental consequence Humans now produce about twice as much reactive nitrogen as the natural system Excess reactive nitrogen can have a series of detrimental environmental effects Scientists hope that increasing global awareness of the nitrogen problem will lead to action on the issue Whether you're a plant or...