What does the ice-core record imply concerning the maximum climatic impact of possible gas hydrate release at Termination 1A?
Thorpe, R.B.; Pyle, J.A.; Nisbet, E.G. (1998). What does the ice-core record imply concerning the maximum climatic impact of possible gas hydrate release at Termination 1A?, in: Henriet, J.-P. et al. Gas hydrates: relevance to world margin stability and climate change. Geological Society Special Publication, 137: pp. 319-326. https://dx.doi.org/10.1144/GSL.SP.1998.137.01.25 In: Henriet, J.-P.; Mienert, J. (1998). Gas hydrates: Relevance to world margin stability and climate change. Geological Society Special Publication, 137. The Geological Society: London. ISBN 1-86239-010-X. 338 pp., more In: Hartley, A.J. et al. (Ed.) Geological Society Special Publication. Geological Society of London: Oxford; London; Edinburgh; Boston, Mass.; Carlton, Vic.. ISSN 0305-8719; e-ISSN 2041-4927, more |
| Keywords | Chemical compounds > Organic compounds > Hydrocarbons > Gas hydrates
Climatic changes
Marine/Coastal |
| Authors | | Top | - Thorpe, R.B.
- Pyle, J.A.
- Nisbet, E.G.
| | |
| Abstract | The rapid climate changes at the terminations marking the end of the last glaciation are poorly understood. CH4 hydrate decomposition has been suggested as a possible trigger of deglaciation. This would imply that there was a large pulse of atmospheric CH4 contemporaneous with Termination 1A. This implication is tested here in a two-stage process using an adapted version of the Cambridge 2-D model. Firstly, the ice-core record was used to place an upper limit on the magnitude of possible CH4 release at Termination 1A. Secondly, the climatic impact of this realistic maximum (RM) pulse was estimated and compared with the actual climate change occurring at deglaciation. It was found that the maximum pulse that could readily be squared with the ice-core record was around 4000 Tg. Its climatic impact was modelled for a range of scenarios covering climate sensitivities from 1.5 to 5.2°C, and involving possible changes in atmospheric CO2 and latitudinal heat transport. The direct radiative effects of this pulse were too small to account for the deglaciation alone, but, for certain combinations of CH4, CO2, and heat transport changes, coupled with high climate sensitivity, it was possible to simulate changes of the same magnitude as those observed. |
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