Climate response of abrupt and steady stratospheric aerosol injection

Abstract

As the consequences of climate change become more evident, efforts are being made to find ways to mitigate these effects. A promising temporary solution is Stratospheric Aerosol Injection (SAI), which is based on reflecting part of the incoming radiation back to space to lower the Earth temperature. Using the Community Earth System Model version 2 (CESM2) with the Community Atmosphere Model version 6 (CAM6) as its atmospheric component, three simulations were made: a high emission scenario called CONTROL, a scenario where SAI is deployed in 2020 (SAI 2020) and a high emission scenario until 2080, when SAI is implemented (SAI 2080). In this project we analyse these simulations to know what effect does it have on temperature, precipitation and precipitation minus evaporation to start SAI in 2020 or to wait until 2080. We find that, although Greenland overcools in SAI 2080, temperature and precipitation globally decrease under both geoengineering simulations relative to CONTROL. Additionally, SAI also keeps values close to present-day conditions, meaning that the geoengineering simulations can partially restore the climate. However, we prove that waiting until 2080 to implement SAI can have negative effects for some ecosystems. Finally, we acknowledge that future research should be made continuing this path.