Nicolas Bellouin¹, Johannes Quaas², Edward Gryspeerdt³, Stefan Kinne⁴, Philip Stier⁵, Duncan Watson-Parris⁶, Olivier Boucher⁷, Ken S Carslaw⁸, Matthew Christensen⁶, Anne-Laure Daniau⁹, Jean-Louis Dufresne¹⁰, Graham Feingold¹¹, Stephanie Fiedler¹², Piers Forster¹³, Andrew Gettelman¹⁴, James Matthew Haywood¹⁵, Florent Malavelle¹⁶, Ulrike Lohmann¹⁷, Thorsten Mauritsen¹⁸, Daniel T McCoy¹³, Gunnar Myhre¹⁹, Johannes Mulmenstadt², David Neubauer²⁰, Anna Possner²¹, Maria Rugenstein²², Yousuke Sato²³, Michael Schulz²⁴, Stephen E Schwartz²⁵, Odran Sourdeval³, Trude Storelvmo²⁶, Velle Toll²⁷, David M Winker²⁸ and Bjorn B Stevens¹², (1)University of Reading, Department of Meteorology, Reading, United Kingdom, (2)University of Leipzig, Leipzig Institute for Meteorology, Leipzig, Germany, (3)University of Leipzig, Leipzig, Germany, (4)Organization Not Listed, Washington, DC, United States, (5)University of Oxford, Department of Physics, Oxford, United Kingdom, (6)University of Oxford, Oxford, United Kingdom, (7)LMD, Paris Cedex 05, France, (8)University of Leeds, Leeds, LS2, United Kingdom, (9)CNRS, Environnnments et Paléoenvironnements Océaniques et Continentaux, Bordeaux, France, (10)Laboratoire de Météorologie Dynamique Palaiseau, Palaiseau Cedex, France, (11)NOAA CSD, Boulder, CO, United States, (12)Max Planck Institute for Meteorology, Hamburg, Germany, (13)University of Leeds, Leeds, United Kingdom, (14)NCAR, Boulder, CO, United States, (15)University of Exeter, Exeter, EX4, United Kingdom, (16)University of Exeter, Exeter, United Kingdom, (17)ETH Zurich, Zurich, Switzerland, (18)Stockholm University, Department of Meteorology, Stockholm, Sweden, (19)Center for International Climate and Environmental Research Oslo, Oslo, Norway, (20)ETH Swiss Federal Institute of Technology Zurich, Zurich, Switzerland, (21)Carnegie Institution for Science Stanford, Department of Global Ecology, Stanford, CA, United States, (22)IMAU University Utrecht, Utrecht, Netherlands, (23)RIKEN, Advanced Institute for Computational Science, Kobe, Japan, (24)Norwegian Meteorological Institute, Climate and Air Pollution Section, Oslo, Norway, (25)Brookhaven National Laboratory, Upton, NY, United States, (26)University of Oslo, Oslo, Norway, (27)University of Reading, Reading, United Kingdom, (28)NASA Langley Research Center, Hampton, VA, United States