Abstract

Exponential increases in the human population and its activities are accelerating global changes, from the climate to land use to loss of species. The rise in atmospheric concentrations of greenhouse gasses, mainly CO₂ from the combustion of fossil fuels, is the most well-known driver of global change (1). Emission of greenhouse gases, which also include methane (CH₄) and nitrous oxide (N₂O), are stoking global warming as well as more frequent and extreme weather events, such as droughts and floods. Land use and pollution also have major impacts on Earth’s future (1). Among these ongoing anthropogenic changes, the biospheric nutrient imbalance between nitrogen (N) and phosphorus (P) is less known and deserves more attention.