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Abstract. We quantify future changes in wildfire burned area and carbon emissions inthe 21st century under four Shared Socioeconomic Pathways (SSPs) scenariosand two SSP5-8.5-based solar geoengineering scenarios with a target surfacetemperature defined by SSP2-4.5 – solar irradiance reduction (G6solar) andstratospheric sulfate aerosol injections (G6sulfur) – and explore themechanisms that drive solar geoengineering impacts on fires. This study isbased on fully coupled climate–chemistry simulations with simulatedoccurrence of fires (burned area and carbon emissions) using the WholeAtmosphere Community Climate Model version 6 (WACCM6) as the atmosphericcomponent of the Community Earth System Model version 2 (CESM2). Globally,total wildfire burned area is projected to increase over the 21st centuryunder scenarios without geoengineering and decrease under the twogeoengineering scenarios. By the end of the century, the two geoengineeringscenarios have lower burned area and fire carbon emissions than not onlytheir base-climate scenario SSP5-8.5 but also the targeted-climate scenarioSSP2-4.5. Geoengineering reduces wildfire occurrence by decreasing surfacetemperature and wind speed and increasing relative humidity and soil water,with the exception of boreal regions where geoengineering increases theoccurrence of wildfires due to a decrease in relative humidity and soilwater compared with the present day. This leads to a global reduction in burnedarea and fire carbon emissions by the end of the century relative to theirbase-climate scenario SSP5-8.5. However, geoengineering also yieldsreductions in precipitation compared with a warming climate, which offsetssome of the fire reduction. Overall, the impacts of the different drivingfactors are larger on burned area than fire carbon emissions. In general,the stratospheric sulfate aerosol approach has a stronger fire-reducingeffect than the solar irradiance reduction approach.
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This content will become publicly available on February 12, 2026
Tropical hydro-climatic responses to global warming and solar radiation modification in the Kelantan River Basin, Malaysia
ABSTRACT Solar radiation modification (SRM) is a potential strategy to rapidly mitigate global warming by reflecting more sunlight into space. However, its impact on tropical hydrological cycles remains underexplored. This study investigates the potential effects of SRM on streamflow in the Kelantan River Basin (KRB) by incorporating climate projections from the Geoengineering Model Intercomparison Project Phase 6 (GeoMIP6) into the Soil and Water Assessment Tool plus (SWAT+) model. Results indicate that UKESM1-0-LL and MPI-ESM1-2-LR exhibit higher uncertainty in representing KRB's climate compared to CNRM-ESM2-1 and IPSL-CM6A-LR. Under SSP5-8.5, maximum and minimum temperatures are projected to increase by up to 3.52 °C by the late 21st century, while SRM scenarios may limit warming to 1.72-2.33 °C, similar to 1.96-2.22 °C under SSP2-4.5. The multi-model ensemble mean projected an inverse V-shaped trend in annual precipitation, with a peak in the mid-21st century before declining, except for G6sulfur, which exhibits a steady decrease. Increases in monthly precipitation from November to January during the 2045-2064 period under all evaluated scenarios may intensify flooding in the KRB. Meanwhile, decreases in streamflow during dry months are projected for the periods 2045-2064 and 2065-2085 under G6sulfur, particularly in the middle and upper basins.
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- Award ID(s):
- 2017113
- PAR ID:
- 10581473
- Publisher / Repository:
- IWA Publishing
- Date Published:
- Journal Name:
- Journal of Water and Climate Change
- Volume:
- 16
- Issue:
- 3
- ISSN:
- 2040-2244
- Page Range / eLocation ID:
- 977 to 994
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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