Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia
Anthropogenic aerosols over South and East Asia currently have a stronger impact on the Asian summer monsoon (ASM) than greenhouse gas emissions, yet projected aerosol emission changes in these regions are subject to considerable uncertainties such as timescale, location, or emission type. We use a...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac3b19 |
| _version_ | 1797747121789599744 |
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| author | Ross Herbert Laura J Wilcox Manoj Joshi Ellie Highwood Dave Frame |
| author_facet | Ross Herbert Laura J Wilcox Manoj Joshi Ellie Highwood Dave Frame |
| author_sort | Ross Herbert |
| collection | DOAJ |
| description | Anthropogenic aerosols over South and East Asia currently have a stronger impact on the Asian summer monsoon (ASM) than greenhouse gas emissions, yet projected aerosol emission changes in these regions are subject to considerable uncertainties such as timescale, location, or emission type. We use a circulation/climate model with idealised aerosol distributions to demonstrate that the sum of ASM responses to aerosol emission reductions in each region is very different to the response to simultaneous reductions in both regions, implying the ASM response to aerosol emissions reductions is highly nonlinear. The phenomenon is independent of whether aerosols are scattering or absorbing, and results from interaction of induced atmospheric circulation changes. The nonlinearity from interactions between aerosol forcing from different regions represents a new source of uncertainty in projections of ASM changes over the next 30–40 years, and may limit the utility of country-dependent aerosol trajectories when considering their Asia-wide effects, though we recommend further work to establish whether the nonlinearity is buffered by other drivers. To understand likely changes in the ASM due to aerosol reductions, countries will need to accurately take account of emissions reductions from across the wider region, rather than approximating them using simple scenarios and emulators. The nonlinearity in the response to forcing therefore presents a regional public goods issue for countries affected by the ASM, as the costs and benefits of aerosol emissions reductions are not internalised; in fact, forcings from different countries such as India and China work jointly to determine outcomes across the region. |
| first_indexed | 2024-03-12T15:46:38Z |
| format | Article |
| id | doaj.art-0fc84b94b2654a269c2cc93ed888a257 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:46:38Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-0fc84b94b2654a269c2cc93ed888a2572023-08-09T15:23:17ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-0117101400510.1088/1748-9326/ac3b19Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East AsiaRoss Herbert0https://orcid.org/0000-0002-2188-7136Laura J Wilcox1https://orcid.org/0000-0001-5691-1493Manoj Joshi2https://orcid.org/0000-0002-2948-2811Ellie Highwood3https://orcid.org/0000-0002-2460-2546Dave Frame4https://orcid.org/0000-0002-0949-3994Department of Meteorology, University of Reading , Reading RG6 6BB, United KingdomNational Centre for Atmospheric Science, Department of Meteorology, University of Reading , Reading RG6 6BB, United KingdomClimatic Research Unit, School of Environmental Sciences, University of East Anglia , Norwich NR4 7TJ, United KingdomDepartment of Meteorology, University of Reading , Reading RG6 6BB, United KingdomNew Zealand Climate Change Research Institute, University of Wellington , PO Box 600, Wellington, New ZealandAnthropogenic aerosols over South and East Asia currently have a stronger impact on the Asian summer monsoon (ASM) than greenhouse gas emissions, yet projected aerosol emission changes in these regions are subject to considerable uncertainties such as timescale, location, or emission type. We use a circulation/climate model with idealised aerosol distributions to demonstrate that the sum of ASM responses to aerosol emission reductions in each region is very different to the response to simultaneous reductions in both regions, implying the ASM response to aerosol emissions reductions is highly nonlinear. The phenomenon is independent of whether aerosols are scattering or absorbing, and results from interaction of induced atmospheric circulation changes. The nonlinearity from interactions between aerosol forcing from different regions represents a new source of uncertainty in projections of ASM changes over the next 30–40 years, and may limit the utility of country-dependent aerosol trajectories when considering their Asia-wide effects, though we recommend further work to establish whether the nonlinearity is buffered by other drivers. To understand likely changes in the ASM due to aerosol reductions, countries will need to accurately take account of emissions reductions from across the wider region, rather than approximating them using simple scenarios and emulators. The nonlinearity in the response to forcing therefore presents a regional public goods issue for countries affected by the ASM, as the costs and benefits of aerosol emissions reductions are not internalised; in fact, forcings from different countries such as India and China work jointly to determine outcomes across the region.https://doi.org/10.1088/1748-9326/ac3b19Asian summer monsoonaerosol–radiation interactionsclimate changeclimate impactspublic goods issue |
| spellingShingle | Ross Herbert Laura J Wilcox Manoj Joshi Ellie Highwood Dave Frame Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia Environmental Research Letters Asian summer monsoon aerosol–radiation interactions climate change climate impacts public goods issue |
| title | Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia |
| title_full | Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia |
| title_fullStr | Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia |
| title_full_unstemmed | Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia |
| title_short | Nonlinear response of Asian summer monsoon precipitation to emission reductions in South and East Asia |
| title_sort | nonlinear response of asian summer monsoon precipitation to emission reductions in south and east asia |
| topic | Asian summer monsoon aerosol–radiation interactions climate change climate impacts public goods issue |
| url | https://doi.org/10.1088/1748-9326/ac3b19 |
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