Abstract
There is an ongoing important debate about the role of water vapour in climate change. Predictions of future climate change depend strongly on the magnitude of the water vapour feedback and until now models have almost exclusively been relied upon to quantify this feedback. In this work we employ observations of water vapour changes, together with detailed radiative calculations to estimate the water vapour feedback for the case of the Mt. Pinatubo eruption. We then compare our observed estimate with that calculated from a relatively large ensemble of simulations from a complex coupled climate model. We calculate an observed water vapour feedback parameter of –1.6 Wm–2 K–1, with uncertainty placing the feedback parameter between –0.9 to –2.5 Wm–2 K–1. The uncertain is principally from natural climate variations that contaminate the volcanic cooling. The observed estimates are consistent with that found in the climate model, with the ensemble average model feedback parameter being –2.0 Wm–2 K–1, with a 5–95% range of –0.4 to –3.6 Wm–2 K–1 (as in the case of the observations, the spread is due to an inability to separate the forced response from natural variability). However, in both the upper troposphere and Southern Hemisphere the observed model water vapour response differs markedly from the observations. The observed range represents a 40%–400% increase in the magnitude of surface temperature change when compared to a fixed water vapour response and is in good agreement with values found in other studies. Variability, both in the observed value and in the climate model’s feedback parameter, between different ensemble members, suggests that the long-term water vapour feedback associated with global climate change could still be a factor of 2 or 3 different than the mean observed value found here and the model water vapour feedback could be quite different from this value; although a small water vapour feedback appears unlikely. We also discuss where in the atmosphere water vapour changes have their largest effect on surface climate.
Similar content being viewed by others
References
Allan RP, Shine KP, Slingo A, Pamment JA (1999) The dependence of outgoing longwave radiation on surface temperature and relative humidity. Q J R Meterol Soc 125: 2103–2126
Bony S, Duvel J, Le Treut H (1995) Observed dependence of the water vapor and clear sky greenhouse effect on surface temperature: comparison with climate warming experiments. Clim Dyn 11: 307–320
Cess RD and 31 Co authors (1990) Intercomparison and interpretation of climate feedback processes in 19 atmospheric general circulation models. J Geophys Res 95: 16,601–16,615
Cess RD and 36 Co authors (1996) Cloud feedback in atmospheric general circulation models: an update. J Geophys Res 101: 12,791–12,794
Collins M (2003) Predictions of climate following volcanic eruptions. Volcanoes and the Earths Atmosphere. AGU monograph, (in press)
Collins M, Tett SFB, Cooper C (2001) The internal climate variability of HadCM3, a version of the Hadley Centre coupled model without flux adjustments. Clim Dyn 17: 61–81
Colman RA (2001) On the vertical extent of atmospheric feedbacks. Clim Dyn 17: 391–405
Gordon C, Cooper C, Senior CA, Banks H, Gregory JM, Johns TC, Mitchell JFB, Wood RA (2000) The simulation of SST, sea ice extents and ocean heat transport in a version of the Hadley Centre coupled model without flux adjustments. Clim Dyn 16: 147–168
Forster PM de F, Shine KP (1997) Radiative forcing and temperature trends from stratospheric ozone depletion. J Geophys Res 102: 10,841–10,855
Forster P M de F, Blackburn M, Glover R, Shine KP (2000) An examination of climate sensitivity for idealised climate change experiments in an intermediate general circulation model. Clim Dyn 16: 833–849
Hall A, Manabe S (1999) The role of water vapor feedback in unperturbed climate variability and global warming. J Clim 12: 2327–2346
Hansen J, Sato M, Ruedy R (1997) Radiative forcing and climate response. J Geophys Res 102: 6831–6894
Hansen J, Lacis A Ruedy R, Sato M, Wilson H (1993) How sensitive is the world’s climate? Natl Geog Res Explor 9: 142–158
Held IM, Soden B J (2000) Water vapor feedback and global warming. Ann Rev Energy Env 25: 441–475
IPCC (1990) Climate change 1990: the IPCC scientific assessment. In: Houghton JT, Jenkins GJ, Ephraums JJ (eds) Cambridge University Press, Cambridge, UK
IPCC (2001) Climate change 2001: the scientific basis. In: Houghton JT, Ding Y, Griggs D J, Noguer M, Van der Linden PJ, Dai X, Maskell K, Johnson CA (eds) Cambridge University Press, Cambridge, UK
Inamdar AK, Ramanathen V (1998) Tropical and global scale interactions among water vapor, atmospheric greenhouse effect and surface temperature. J Geophys Res 103: 32,177–32,194
Jones PD New M, Parker, DE, Martin S, Rigor IG (1999) Surface air temperature and its changes over the last 150 years. Rev Geophys 37: 173–199
Joshi M Shine K P, Ponater M, Stuber N, Sausen R, Li L (2003) A comparison of climate response to different radiative forcings in three general circulation models: towards an improved metric of climate change. Clim Dyn (in press)
Lau K, Ho C, Chou M (1996) Water vapor and cloud feedback over the tropical oceans: can we use ENSO as a surrogate for climate change? Geophys Res Lett 23: 2971–2974
Lindzen RS (1990) Some coolness regarding global warming. Bull Am Meteorol Soc 71: 288–299
Randel DL, Vonder Haar TH, Ringerud MA et al. (1996) A new global water vapor dataset. Bull Am Meteorol Soc 77: 1233–1246
Read WG, Waters JW, Froidevaux F Flower DA, Jarnot RF, Hartmann DL, Harwood RS (1995) Upper tropospheric water vapor from UARS MLS. Bull Am Meteorol Soc 76: 2381–2389
Sato M, Hansen JE, McCormick MP, Pollack JB (1993) Stratospheric aerosol optical depths. 1850–1990, J Geophys Res 98: 22,987–22,994
Schneider EK, Kirtman BP, Lindzen RS (1999) Tropospheric water vapor and climate sensitivity. J Atmos Sci 36: 1649–1658
Shine KP (1991) On the cause of relative strength of greenhouse gases such as the halocarbons. J Atmos Sci 48: 1513–1518
Shine KP, Sinha A (1992) Sensitivity of the Earth’s climate to height dependent changes in the water vapour mixing ratio. Nature 354: 382–384
Soden BJ, Wetherald RT, Stenchikov GL, Robock A (2002) Global cooling after the eruption of Mt. Pinatubo: a test of climate feedback by water vapor. Sci 296: 727–730
Acknowledgements
PMF was funded by an UK Natural Environment Research Council fellowship. Bill Read is thanked for providing the MLS data. MC was supported by the UK Natural Environment Research Council Coupled Ocean-Atmosphere and European Climate Thematic Programme. We are grateful to Gareth Jones and Peter Stott of the Hadley Centre for proving details of the model simulations. Brian Soden and an anonymous reviewer are thanked for helpful comments.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
de F. Forster, P.M., Collins, M. Quantifying the water vapour feedback associated with post-Pinatubo global cooling. Climate Dynamics 23, 207–214 (2004). https://doi.org/10.1007/s00382-004-0431-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00382-004-0431-z