A new feedback on climate change from the hydrological cycle

Williams, P. D. ORCID: https://orcid.org/0000-0002-9713-9820, Guilyardi, E. ORCID: https://orcid.org/0000-0002-2255-8625, Sutton, R. T. ORCID: https://orcid.org/0000-0001-8345-8583, Gregory, J. M. ORCID: https://orcid.org/0000-0003-1296-8644 and Madec, G. (2007) A new feedback on climate change from the hydrological cycle. Geophysical Research Letters, 34 (8). L08706. ISSN 0094-8276 doi: 10.1029/2007GL029275

Abstract/Summary

An intensification of the hydrological cycle is a likely consequence of global warming. But changes in the hydrological cycle could affect sea-surface temperature by modifying diffusive ocean heat transports. We investigate this mechanism by studying a coupled general circulation model sensitivity experiment in which the hydrological cycle is artificially amplified. We find that the amplified hydrological cycle depresses sea-surface temperature by enhancing ocean heat uptake in low latitudes. We estimate that a 10% increase in the hydrological cycle will contribute a basin-scale sea-surface temperature decrease of around 0.1°C away from high latitudes, with larger decreases locally. We conclude that an intensified hydrological cycle is likely to contribute a weak negative feedback to anthropogenic climate change.