African Climate Change Uncertainty in Perturbed Physics Ensembles: Implications of Global Warming to 4°C and BeyondSource: Journal of Climate:;2014:;volume( 027 ):;issue: 012::page 4677DOI: 10.1175/JCLI-D-13-00612.1Publisher: American Meteorological Society
Abstract: he importance of investigating regional climate changes associated with degrees of global warming is increasingly being recognized, but the majority of relevant research has been based on multimodel ensembles (MMEs) from the Coupled Model Intercomparison Project (CMIP). This has left two important questions unanswered: Are there plausible futures which are not represented by the models in CMIP? And, how would regional climates evolve under enhanced global warming, beyond 4°C? In this paper, two perturbed physics ensembles (PPEs) are used to address these issues with reference to African precipitation. Examination of model versions that generate warming greater than 4°C in the twenty-first century shows that changes in African precipitation are enhanced gradually, even to high global temperatures; however, there may be nonlinearities that are not incorporated here due to limited model complexity. The range of projections from the PPEs is compared to data from phases 3 and 5 of CMIP (CMIP3 and CMIP5), revealing regional differences. This is partly the result of implausible model versions, but the PPE dataset can be justifiably constrained given its size and systematic nature, highlighting an additional advantage over MMEs. After applying constraints, the PPEs still show changes that are outside the range of CMIP, most prominently strong dry signals in west equatorial Africa and the Sahel, implying that MMEs may underestimate risks for these regions. Analysis of African precipitation changes therefore demonstrates that regional assessments that rely on CMIP3 and CMIP5 may overlook uncertainties associated with model parameterizations and pronounced warming. More systematic approaches are needed for conservative estimates of danger.
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contributor author | James, Rachel | |
contributor author | Washington, Richard | |
contributor author | Rowell, David P. | |
date accessioned | 2017-06-09T17:09:30Z | |
date available | 2017-06-09T17:09:30Z | |
date copyright | 2014/06/01 | |
date issued | 2014 | |
identifier issn | 0894-8755 | |
identifier other | ams-80295.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4223171 | |
description abstract | he importance of investigating regional climate changes associated with degrees of global warming is increasingly being recognized, but the majority of relevant research has been based on multimodel ensembles (MMEs) from the Coupled Model Intercomparison Project (CMIP). This has left two important questions unanswered: Are there plausible futures which are not represented by the models in CMIP? And, how would regional climates evolve under enhanced global warming, beyond 4°C? In this paper, two perturbed physics ensembles (PPEs) are used to address these issues with reference to African precipitation. Examination of model versions that generate warming greater than 4°C in the twenty-first century shows that changes in African precipitation are enhanced gradually, even to high global temperatures; however, there may be nonlinearities that are not incorporated here due to limited model complexity. The range of projections from the PPEs is compared to data from phases 3 and 5 of CMIP (CMIP3 and CMIP5), revealing regional differences. This is partly the result of implausible model versions, but the PPE dataset can be justifiably constrained given its size and systematic nature, highlighting an additional advantage over MMEs. After applying constraints, the PPEs still show changes that are outside the range of CMIP, most prominently strong dry signals in west equatorial Africa and the Sahel, implying that MMEs may underestimate risks for these regions. Analysis of African precipitation changes therefore demonstrates that regional assessments that rely on CMIP3 and CMIP5 may overlook uncertainties associated with model parameterizations and pronounced warming. More systematic approaches are needed for conservative estimates of danger. | |
publisher | American Meteorological Society | |
title | African Climate Change Uncertainty in Perturbed Physics Ensembles: Implications of Global Warming to 4°C and Beyond | |
type | Journal Paper | |
journal volume | 27 | |
journal issue | 12 | |
journal title | Journal of Climate | |
identifier doi | 10.1175/JCLI-D-13-00612.1 | |
journal fristpage | 4677 | |
journal lastpage | 4692 | |
tree | Journal of Climate:;2014:;volume( 027 ):;issue: 012 | |
contenttype | Fulltext |