A global study shows that the effects of extreme drought -- which is expected to increase in frequency with climate change -- has been greatly underestimated for grasslands and shrublands. The findings quantify the impact of extreme short-term drought on grassland and shrubland ecosystems across six continents with a level of detail that was not previously possible. It is the first time an experiment this extensive has been undertaken to generate a baseline understanding of the potential losses of plant productivity in these vital ecosystems.