Abstract 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.
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Response of the Indian summer monsoon to global warming, solar geoengineering and its termination
Abstract The response of the Indian Summer Monsoon (ISM) to global warming, solar geoengineering and its termination is examined using the multi-model mean of seven global climate model simulations from G2 experiment of the Geoengineering Model Intercomparison Project. Under the global warming scenario, land–ocean temperature contrasts and low-level monsoon circulation progressively strengthen accompanied by enhanced precipitation over the Indian subcontinent. Notably, in the solar geoengineered scenario, marginal surface cooling is projected over the majority of the ISM region, and there is strengthening of both upper and lower level circulation. However, preferential precipitation near Western Ghats leads to dry bias over majority of Indian land. Upon the termination of the geoengineering, the climatic conditions—temperature, precipitation, winds and moisture would abruptly change to what it would have been under the global warming scenario. Thus, this may be important to note that such changes may need attention for the future mitigation and adaptation purposes if solar geoengineering is required to implement in future.
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- Award ID(s):
- 1931641
- PAR ID:
- 10249460
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 11
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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