New Insights into Natural Variability and Anthropogenic Forcing of Global/Regional Climate Evolution

TitleNew Insights into Natural Variability and Anthropogenic Forcing of Global/Regional Climate Evolution
Publication TypeJournal Article
Year of Publication2019
Journalnpj Climate and Atmospheric Science
Volume2
Number1
Date Published06/2019
Abstract / Summary

Because of natural decadal climate variability—Atlantic multi-decadal variability (AMV) and Pacific decadal variability (PDV) —the increase of global mean surface air temperature (GMSAT) has not been monotonic although atmospheric greenhouse gas (GHG) concentrations have been increasing continuously. It has always been a challenge regarding how to separate the effects of these two factors on GMSAT. Here, we find a physically based quasi-linear relationship between transient GMSAT and well-mixed GHG changes for both observations and model simulations. With AMV and PDV defined as the combination of variability over both the Atlantic and Pacific basins after the GHG-related trend is removed, we show that the observed GMSAT changes from 1880 to 2017 on multi-decadal or longer timescales receive contributions of about 70% from GHGs, while AMV and PDV together account for roughly 30%.

URLhttp://dx.doi.org/10.1038/s41612-019-0075-7
DOI10.1038/s41612-019-0075-7
Journal: npj Climate and Atmospheric Science
Year of Publication: 2019
Volume: 2
Number: 1
Date Published: 06/2019

Because of natural decadal climate variability—Atlantic multi-decadal variability (AMV) and Pacific decadal variability (PDV) —the increase of global mean surface air temperature (GMSAT) has not been monotonic although atmospheric greenhouse gas (GHG) concentrations have been increasing continuously. It has always been a challenge regarding how to separate the effects of these two factors on GMSAT. Here, we find a physically based quasi-linear relationship between transient GMSAT and well-mixed GHG changes for both observations and model simulations. With AMV and PDV defined as the combination of variability over both the Atlantic and Pacific basins after the GHG-related trend is removed, we show that the observed GMSAT changes from 1880 to 2017 on multi-decadal or longer timescales receive contributions of about 70% from GHGs, while AMV and PDV together account for roughly 30%.

DOI: 10.1038/s41612-019-0075-7
Citation:
Wu, T, A Hu, F Gao, J Zhang, and G Meehl.  2019.  "New Insights into Natural Variability and Anthropogenic Forcing of Global/Regional Climate Evolution."  npj Climate and Atmospheric Science 2(1).  https://doi.org/10.1038/s41612-019-0075-7.