Large Regional Shortwave Forcing by Anthropogenic Methane Informed by Jovian Observations

TitleLarge Regional Shortwave Forcing by Anthropogenic Methane Informed by Jovian Observations
Publication TypeJournal Article
Year of Publication2018
AuthorsCollins, William D., Feldman Daniel R., Kuo Chaincy, and Nguyen Newton H.
JournalScience Advances
Volume4
Number9
Pageseaas9593
Date Published09/2018
Abstract

Recently, it was recognized that widely used calculations of methane radiative forcing systematically underestimated its global value by 15% by omitting its shortwave effects. We show that shortwave forcing by methane can be accurately calculated despite considerable uncertainty and large gaps in its shortwave spectroscopy. We demonstrate that the forcing is insensitive, even when confronted with much more complete methane absorption spectra extending to violet light wavelengths derived from observations of methane-rich Jovian planets. We undertake the first spatially resolved global calculations of this forcing and find that it is dependent on bright surface features and clouds. Localized annual mean forcing from preindustrial to present-day methane increases approaches +0.25 W/m2, 10 times the global annualized shortwave forcing and 43% of the total direct CH4 forcing. Shortwave forcing by anthropogenic methane is sufficiently large and accurate to warrant its inclusion in historical analyses, projections, and mitigation strategies for climate change.

URLhttp://dx.doi.org/10.1126/sciadv.aas9593
DOI10.1126/sciadv.aas9593
Journal: Science Advances
Number: 9
Volume: 4

Recently, it was recognized that widely used calculations of methane radiative forcing systematically underestimated its global value by 15% by omitting its shortwave effects. We show that shortwave forcing by methane can be accurately calculated despite considerable uncertainty and large gaps in its shortwave spectroscopy. We demonstrate that the forcing is insensitive, even when confronted with much more complete methane absorption spectra extending to violet light wavelengths derived from observations of methane-rich Jovian planets. We undertake the first spatially resolved global calculations of this forcing and find that it is dependent on bright surface features and clouds. Localized annual mean forcing from preindustrial to present-day methane increases approaches +0.25 W/m2, 10 times the global annualized shortwave forcing and 43% of the total direct CH4 forcing. Shortwave forcing by anthropogenic methane is sufficiently large and accurate to warrant its inclusion in historical analyses, projections, and mitigation strategies for climate change.

DOI: 10.1126/sciadv.aas9593
Year of Publication: 2018
Citation:
Collins, W, D Feldman, C Kuo, and NH Nguyen.  2018.  "Large Regional Shortwave Forcing by Anthropogenic Methane Informed by Jovian Observations."  Science Advances 4(9): eaas9593, doi:10.1126/sciadv.aas9593.