Quantifying the role of internal variability in the temperature we expect to observe in the coming decades
On short (15-year) to mid-term (30-year) time-scales how the Earth’s surface temperature evolves can be dominated by internal variability as demonstrated by the global-warming pause or ‘hiatus’. In this study, we use six single model initial-condition large ensembles (SMILEs) and the Coupled Model I...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab7d02 |
| _version_ | 1797747519466242048 |
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| author | Nicola Maher Flavio Lehner Jochem Marotzke |
| author_facet | Nicola Maher Flavio Lehner Jochem Marotzke |
| author_sort | Nicola Maher |
| collection | DOAJ |
| description | On short (15-year) to mid-term (30-year) time-scales how the Earth’s surface temperature evolves can be dominated by internal variability as demonstrated by the global-warming pause or ‘hiatus’. In this study, we use six single model initial-condition large ensembles (SMILEs) and the Coupled Model Intercomparison Project 5 (CMIP5) to visualise the role of internal variability in controlling possible observable surface temperature trends in the short-term and mid-term projections from 2019 onwards. We confirm that in the short-term, surface temperature trend projections are dominated by internal variability, with little influence of structural model differences or warming pathway. Additionally we demonstrate that this result is independent of the model-dependent estimate of the magnitude of internal variability. Indeed, and perhaps counter intuitively, in all models a lack of warming, or even a cooling trend could be observed at all individual points on the globe, even under the largest greenhouse gas emissions. The near-equivalence of all six SMILEs and CMIP5 demonstrates the robustness of this result to the choice of models used. On the mid-term time-scale, we confirm that structural model differences and scenario uncertainties play a larger role in controlling surface temperature trend projections than they did on the shorter time-scale. In addition we show that whether internal variability still dominates, or whether model uncertainties and internal variability are a similar magnitude, depends on the estimate of internal variability, which differs between the SMILEs. Finally we show that even out to thirty years large parts of the globe (or most of the globe in MPI-GE and CMIP5) could still experience no-warming due to internal variability. |
| first_indexed | 2024-03-12T15:51:45Z |
| format | Article |
| id | doaj.art-546dd9ac94be4a49871f3cf387b19a2b |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:51:45Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-546dd9ac94be4a49871f3cf387b19a2b2023-08-09T15:05:57ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115505401410.1088/1748-9326/ab7d02Quantifying the role of internal variability in the temperature we expect to observe in the coming decadesNicola Maher0Flavio Lehner1Jochem Marotzke2Max Planck Institute for Meteorology , Hamburg, GermanyInstitute for Atmospheric and Climate Science , ETH Zürich, Zürich, Switzerland and Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, United States of AmericaMax Planck Institute for Meteorology , Hamburg, GermanyOn short (15-year) to mid-term (30-year) time-scales how the Earth’s surface temperature evolves can be dominated by internal variability as demonstrated by the global-warming pause or ‘hiatus’. In this study, we use six single model initial-condition large ensembles (SMILEs) and the Coupled Model Intercomparison Project 5 (CMIP5) to visualise the role of internal variability in controlling possible observable surface temperature trends in the short-term and mid-term projections from 2019 onwards. We confirm that in the short-term, surface temperature trend projections are dominated by internal variability, with little influence of structural model differences or warming pathway. Additionally we demonstrate that this result is independent of the model-dependent estimate of the magnitude of internal variability. Indeed, and perhaps counter intuitively, in all models a lack of warming, or even a cooling trend could be observed at all individual points on the globe, even under the largest greenhouse gas emissions. The near-equivalence of all six SMILEs and CMIP5 demonstrates the robustness of this result to the choice of models used. On the mid-term time-scale, we confirm that structural model differences and scenario uncertainties play a larger role in controlling surface temperature trend projections than they did on the shorter time-scale. In addition we show that whether internal variability still dominates, or whether model uncertainties and internal variability are a similar magnitude, depends on the estimate of internal variability, which differs between the SMILEs. Finally we show that even out to thirty years large parts of the globe (or most of the globe in MPI-GE and CMIP5) could still experience no-warming due to internal variability.https://doi.org/10.1088/1748-9326/ab7d02internal variabilitySMILEslarge ensemblesshort-term projectionsmid-term projectionssurface temperature |
| spellingShingle | Nicola Maher Flavio Lehner Jochem Marotzke Quantifying the role of internal variability in the temperature we expect to observe in the coming decades Environmental Research Letters internal variability SMILEs large ensembles short-term projections mid-term projections surface temperature |
| title | Quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| title_full | Quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| title_fullStr | Quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| title_full_unstemmed | Quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| title_short | Quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| title_sort | quantifying the role of internal variability in the temperature we expect to observe in the coming decades |
| topic | internal variability SMILEs large ensembles short-term projections mid-term projections surface temperature |
| url | https://doi.org/10.1088/1748-9326/ab7d02 |
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