Different types of drought under climate change or geoengineering: Systematic review of societal implications

Climate change and solar geoengineering have different implications for drought. can “speed up” the hydrological cycle, but it causesgreater evapotranspiration than historical climate because of higher temperatures. Solar (stratospheric aerosol injection), on other hand, tends to “slow down” cycle while reducing potential evapotranspiration. There are two common definitions drought that take this into account; rainfall-only (SPI) potential-evapotranspiration (SPEI). In regions Africa, result in versions droughts each scenario, with drier rainfall under (SPEI) change. However, societal these types not clear. We present a systematic review all papers comparing relationship between real-world outcomes (streamflow, vegetation, agricultural yields) Africa. also correlate (SPI SPEI) vegetation conditions across continent. find potential-evapotranspiration-droughts tend be more closely related conditions, rainfall-droughts streamflows many regions, adaptation plans likely affected differently by types. parts East Africa coastal West could exacerbate both drought, which has current investments water infrastructure. The reverse is true Southern Sahel, sectors sensitive rainfall-drought (SPI), such as reservoir management, see reduced availability geoengineering, potential-evapotranspiration-drought (SPEI), rainfed agriculture, increased geoengineering. Given futures sectors, we recommend deliberations include widest possible representation stakeholders.