
1. Ethics, governance, and public perceptions
Solar Radiation Modification and Global Health Equity: Exploring Systemic Risks and Implications for the Global South
Trisha Patel
This study investigates the projected impacts of Stratospheric Aerosol Injection (SAI)
geoengineering on temperature and precipitation extremes across Tanzania's agro-ecological
zones in the future (2075–2095) under a high-emission scenario (RCP8.5). Using simulations from
the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project, we evaluate the
project’s main feedback experiment (GLENS), which simulates sulphur dioxide (SO2) injections
into the tropics at 22.8 km altitude. We analysed extreme temperature and precipitation indices
describing moderate extremes as defined by the Expert Team on Climate Change Detection and
Indices (ETCCDI), to assess the effects of SAI on extremes across Tanzania. Results show that SAI
could offset the projected warming under RCP8.5, reducing temperature by 1.5–4°C across
Tanzania, particularly in the south and southwest. However, the effect on precipitation extremes
is more varied. While SAI could reverse the projected increase in precipitation during the long rain
season (MAM) and reduce extreme rainfall over southern and southwestern (-20 mm/month) and
northwestern Tanzania (over -100 mm/month), it may exacerbate drying conditions elsewhere,
especially in the southwest during OND (short rains). These changes could have implications for
health, agriculture, tourism, infrastructure, and mining. This study underscores the potential of
SAI to alleviate some climate change impacts while posing new challenges. Careful
consideration of the region-specific impacts of SAI is essential for policy-making and climate
intervention strategies.