loading page

Bounding aerosol radiative forcing of climate change
  • +30
  • Nicolas Bellouin,
  • Johannes Quaas,
  • Ed Gryspeerdt,
  • Stefan Kinne,
  • Philip Stier,
  • Duncan Watson-Parris,
  • Olivier Boucher,
  • Ken Carslaw,
  • Matt Christensen,
  • Anne-Laure Daniau,
  • Jean-Louis Dufresne,
  • Graham Feingold,
  • Stephanie Fiedler,
  • Piers Forster,
  • Andrew Gettelman,
  • Jim Haywood,
  • Florent Malavelle,
  • Ulrike Lohmann,
  • Thorsten Mauritsen,
  • Daniel McCoy,
  • Gunnar Myhre,
  • Johannes Muelmenstaedt,
  • David Neubauer,
  • Anna Possner,
  • Maria Rugenstein,
  • Yousuke Sato,
  • Michael Schulz,
  • Stephen Schwartz,
  • Odran Sourdeval,
  • Trude Storelvmo,
  • Velle Toll,
  • David Winker,
  • Bjorn Stevens
Nicolas Bellouin
Department of Meteorology, University of Reading

Corresponding Author:n.bellouin@reading.ac.uk

Author Profile
Johannes Quaas
University of Leipzig
Author Profile
Ed Gryspeerdt
Imperial College London
Author Profile
Stefan Kinne
Max Planck Institute for Meteorology, Hamburg
Author Profile
Philip Stier
University of Oxford
Author Profile
Duncan Watson-Parris
University of Oxford
Author Profile
Olivier Boucher
Laboratoire de Meteorologie Dynamique
Author Profile
Ken Carslaw
University of Leeds
Author Profile
Matt Christensen
University of Oxford
Author Profile
Anne-Laure Daniau
EPOC UMR5805, CNRS, University of Bordeaux
Author Profile
Jean-Louis Dufresne
Laboratoire de Meteorologie Dynamique
Author Profile
Graham Feingold
NOAA CSD
Author Profile
Stephanie Fiedler
Max Planck Institute for Meteorology, Hamburg
Author Profile
Piers Forster
University of Leeds
Author Profile
Andrew Gettelman
NCAR
Author Profile
Jim Haywood
University of Exeter, UK Met Office
Author Profile
Florent Malavelle
University of Exeter
Author Profile
Ulrike Lohmann
ETH Zurich
Author Profile
Thorsten Mauritsen
Stockholm University
Author Profile
Daniel McCoy
University of Leeds
Author Profile
Gunnar Myhre
Center for International Climate and Environmental Research Oslo
Author Profile
Johannes Muelmenstaedt
University of Leipzig
Author Profile
David Neubauer
ETH Swiss Federal Institute of Technology Zurich
Author Profile
Anna Possner
University of Frankfurt
Author Profile
Maria Rugenstein
Max Planck Institute for Meteorology, Hamburg
Author Profile
Yousuke Sato
Hokudai University
Author Profile
Michael Schulz
Norwegian Meteorological Institute
Author Profile
Stephen Schwartz
Brookhaven National Laboratory
Author Profile
Odran Sourdeval
Universite de Lille
Author Profile
Trude Storelvmo
University of Oslo
Author Profile
Velle Toll
University of Tartu
Author Profile
David Winker
NASA Langley Research Center
Author Profile
Bjorn Stevens
Max Planck Institute for Meteorology, Hamburg
Author Profile

Abstract

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth’s radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This poster presents the outcome of an international workshop and subsequent review paper, which quantify the likely range of aerosol radiative forcing over the industrial era based on multiple lines of evidence, including modelling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes narrow the range of the forcing from aerosol-radiation interactions compared to the latest assessment by the Intergovernmental Panel on Climate Change (IPCC). A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction and on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to total aerosol radiative forcing ranges that are of similar width to the last IPCC assessment but more clearly based on physical arguments.