Risks for the global freshwater system at 1.5 °C and 2 °C global warming
To support implementation of the Paris Agreement, the new HAPPI ensemble of 20 bias-corrected simulations of four climate models was used to drive two global hydrological models in worlds approximately 1.5 °C and 2 °C warmer than pre-industrial. Seven hydrological hazard indicators were analysed characterizing freshwater-related hazards for humans, freshwater biota and vegetation. The findings show that areas with either significantly wetter or drier conditions are smaller in the 1.5 °C world for all but one indicator. The incremental impact between 1.5 °C and 2 °C on high flows would be felt most by low income and lower middle income countries, the effect on soil moisture and low flows most by high income countries.