Changes to population-based emergence of climate change from CMIP5 to CMIP6
The Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and s...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/aca91e |
| _version_ | 1827869703747403776 |
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| author | Hunter C Douglas Luke J Harrington Manoj Joshi Ed Hawkins Laura E Revell David J Frame |
| author_facet | Hunter C Douglas Luke J Harrington Manoj Joshi Ed Hawkins Laura E Revell David J Frame |
| author_sort | Hunter C Douglas |
| collection | DOAJ |
| description | The Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and stronger emergence under the Shared Socio-economic Pathways than the previous generation did under corresponding Representative Concentration Pathways. Spatial patterns of emergence also change between generations of models; under a high emissions scenario, mid-century S/N is lower than previous studies indicated in Central Africa, South Asia, and parts of South America, West Africa, East Asia, and Western Europe, but higher in most other populated areas. We show that these global and regional changes are caused by a combination of higher effective climate sensitivity in the CMIP6 ensemble, as well as changes to emissions pathways, component-wise effective radiative forcing, and region-scale climate responses between model generations. We also present the first population-weighted calculation of climate change emergence for the CMIP6 ensemble, quantifying the number of people exposed to increasing degrees of abnormal temperatures now and into the future. Our results confirm the expected inequity of climate change-related impacts in the decades between now and the 2050 target for net-zero emissions held by many countries. These findings underscore the importance of concurrent investments in both mitigation and adaptation. |
| first_indexed | 2024-03-12T15:47:53Z |
| format | Article |
| id | doaj.art-5b6ce241c9024e8e833324a0dbaac887 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:47:53Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5b6ce241c9024e8e833324a0dbaac8872023-08-09T15:20:02ZengIOP PublishingEnvironmental Research Letters1748-93262022-01-0118101401310.1088/1748-9326/aca91eChanges to population-based emergence of climate change from CMIP5 to CMIP6Hunter C Douglas0https://orcid.org/0000-0002-5411-7656Luke J Harrington1https://orcid.org/0000-0002-1699-6119Manoj Joshi2https://orcid.org/0000-0002-2948-2811Ed Hawkins3https://orcid.org/0000-0001-9477-3677Laura E Revell4https://orcid.org/0000-0002-8974-7703David J Frame5https://orcid.org/0000-0002-0949-3994New Zealand Climate Change Research Institute, Victoria University of Wellington Te Herenga Waka , Wellington, New ZealandTe Aka Mātuatua School of Science, University of Waikato , Hamilton, New ZealandClimatic Research Unit, University of East Anglia , Norwich, United Kingdom; School of Environmental Sciences, University of East Anglia , Norwich, United KingdomDepartment of Meteorology, University of Reading , Reading, United KingdomSchool of Physical and Chemical Sciences, University of Canterbury , Christchurch, New ZealandSchool of Physical and Chemical Sciences, University of Canterbury , Christchurch, New Zealand; School of Earth and Environment, University of Canterbury , Christchurch, New ZealandThe Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and stronger emergence under the Shared Socio-economic Pathways than the previous generation did under corresponding Representative Concentration Pathways. Spatial patterns of emergence also change between generations of models; under a high emissions scenario, mid-century S/N is lower than previous studies indicated in Central Africa, South Asia, and parts of South America, West Africa, East Asia, and Western Europe, but higher in most other populated areas. We show that these global and regional changes are caused by a combination of higher effective climate sensitivity in the CMIP6 ensemble, as well as changes to emissions pathways, component-wise effective radiative forcing, and region-scale climate responses between model generations. We also present the first population-weighted calculation of climate change emergence for the CMIP6 ensemble, quantifying the number of people exposed to increasing degrees of abnormal temperatures now and into the future. Our results confirm the expected inequity of climate change-related impacts in the decades between now and the 2050 target for net-zero emissions held by many countries. These findings underscore the importance of concurrent investments in both mitigation and adaptation.https://doi.org/10.1088/1748-9326/aca91eclimate change emergenceCMIP6SSPsRCPsinequalityCMIP5 |
| spellingShingle | Hunter C Douglas Luke J Harrington Manoj Joshi Ed Hawkins Laura E Revell David J Frame Changes to population-based emergence of climate change from CMIP5 to CMIP6 Environmental Research Letters climate change emergence CMIP6 SSPs RCPs inequality CMIP5 |
| title | Changes to population-based emergence of climate change from CMIP5 to CMIP6 |
| title_full | Changes to population-based emergence of climate change from CMIP5 to CMIP6 |
| title_fullStr | Changes to population-based emergence of climate change from CMIP5 to CMIP6 |
| title_full_unstemmed | Changes to population-based emergence of climate change from CMIP5 to CMIP6 |
| title_short | Changes to population-based emergence of climate change from CMIP5 to CMIP6 |
| title_sort | changes to population based emergence of climate change from cmip5 to cmip6 |
| topic | climate change emergence CMIP6 SSPs RCPs inequality CMIP5 |
| url | https://doi.org/10.1088/1748-9326/aca91e |
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