Articles | Volume 10, issue 5
Geosci. Model Dev., 10, 2057–2116, 2017

Special issue: Coupled Model Intercomparison Project Phase 6 (CMIP6) Experimental...

Geosci. Model Dev., 10, 2057–2116, 2017

Model experiment description paper 31 May 2017

Model experiment description paper | 31 May 2017

Historical greenhouse gas concentrations for climate modelling (CMIP6)

Malte Meinshausen1,2,3, Elisabeth Vogel1,2, Alexander Nauels1,2, Katja Lorbacher1,2, Nicolai Meinshausen4, David M. Etheridge5, Paul J. Fraser5, Stephen A. Montzka6, Peter J. Rayner2, Cathy M. Trudinger5, Paul B. Krummel5, Urs Beyerle7, Josep G. Canadell8, John S. Daniel9, Ian G. Enting10,*, Rachel M. Law5, Chris R. Lunder11, Simon O'Doherty12, Ron G. Prinn13, Stefan Reimann14, Mauro Rubino5,15, Guus J. M. Velders16, Martin K. Vollmer14, Ray H. J. Wang17, and Ray Weiss18 Malte Meinshausen et al.
  • 1Australian-German Climate & Energy College, The University of Melbourne, Parkville, Victoria, Australia
  • 2Department of Earth Sciences, The University of Melbourne, Parkville, Victoria, Australia
  • 3Potsdam Institute for Climate Impact Research, Potsdam, Germany
  • 4Seminar for Statistics, Swiss Federal Institute of Technology (ETH Zurich), Zurich, Switzerland
  • 5CSIRO Climate Science Centre, Oceans and Atmosphere, Aspendale, Victoria, Australia
  • 6NOAA, Earth System Research Laboratory, Global Monitoring Division, Boulder, Colorado, USA
  • 7Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology (ETH Zurich), Zurich, Switzerland
  • 8Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, ACT, Australia
  • 9NOAA, Earth System Research Laboratory, Chemical Sciences Division, Boulder, Colorado, USA
  • 10The University of Melbourne, Victoria, Australia
  • 11Norwegian Institute for Air Research, Kjeller, Norway
  • 12University of Bristol, Bristol, UK
  • 13MIT, Cambridge, Massachusetts, USA
  • 14Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Air Pollution and Environmental Technology, Dübendorf, Switzerland
  • 15Dipartimento di matematica e fisica, Seconda Università degli studi di Napoli, Caserta, Italy
  • 16National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
  • 17School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
  • 18Scripps Institution of Oceanography, La Jolla, California, USA
  • *retired

Abstract. Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and – partially offset by net cooling effects by aerosols – are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project – Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850–2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at and While the minimum CMIP6 recommendation is to use the global- and annual-mean time series, modelling groups can also choose our monthly and latitudinally resolved concentrations, which imply a stronger radiative forcing in the Northern Hemisphere winter (due to the latitudinal gradient and seasonality).

Short summary
Climate change is primarily driven by human-induced increases of greenhouse gas (GHG) concentrations. Based on ongoing community efforts (e.g. AGAGE and NOAA networks, ice cores), this study presents historical concentrations of CO2, CH4, N2O and 40 other GHGs from year 0 to year 2014. The data is recommended as input for climate models for pre-industrial, historical runs under CMIP6. Global means, but also latitudinal by monthly surface concentration fields are provided.