Climate change has been projected to increase the intensity and magnitude of extreme temperature in Indonesia. Solar radiation management (SRM) has been proposed as a strategy to temporarily combat global warming, buying time for negative emissions. Although the global impacts of SRM have been extensively studied in recent years, regional impacts, especially in the tropics, have received much less attention. This article investigates the potential stratospheric sulphate aerosol injection (SAI) to modify mean and extreme temperature, as well as the relative humidity and wet bulb temperature (WBT) change over Indonesian Maritime Continent (IMC) based on simulations from three different earth system models. We applied a simple downscaling method and corrected the bias of model output to reproduce historical temperatures and relative humidity over IMC. We evaluated changes in geoengineering model intercomparison project (GeoMIP) experiment G4, an SAI experiment in 5 Tg of SO2into the equatorial lower stratosphere between 2020 and 2069, concurrent with the RCP4.5 emissions scenario. G4 is able to significantly reduce the temperature means and extremes, and although differences in magnitude of response and spatial pattern occur, there is a generally consistent response. The spatial response of changes forced by RCP4.5 scenario and G4 are notably heterogeneous in the archipelago, highlighting uncertainties that would be critical in assessing socio‐economic consequences of both doing, and not doing G4. In general, SAI has bigger impacts in reducing temperatures over land than oceans, and the southern monsoon region shows more variability. G4 is also effective at reducing the likelihood of WBT > 27°C events compared with RCP4.5 after some years of SAI deployment as well as during the post‐termination period of SAI. Regional downscaling may be an effective tool in obtaining policy‐relevant information about local effects of different future scenarios involving SAI.
Solar geoengineering that aims to offset global warming could nonetheless alter atmospheric temperature gradients and humidity and thus affect the extratropical storm tracks. Here, we first analyze climate model simulations from experiment G1 of the Geoengineering Model Intercomparison Project, in which a reduction in incoming solar radiation balances a quadrupling of CO2. The Northern Hemisphere extratropical storm track weakens by a comparable amount in G1 as it does for increased CO2only. The Southern Hemisphere storm track also weakens in G1, in contrast to a strengthening and poleward shift for increased CO2. Using mean available potential energy, we show that the changes in zonal‐mean temperature and humidity are sufficient to explain the different responses of storm‐track intensity. We also demonstrate similar weakening in a more complex geoengineering scenario. Our results offer insight into how geoengineering affects storm tracks, highlighting the potential for geoengineering to induce novel climate changes.
more » « less- NSF-PAR ID:
- 10455331
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 47
- Issue:
- 11
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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