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Millennial timescale carbon cycle and climate change in an efficient Earth system model

Lenton, T.M.; Williamson, M.S.; Edwards, N.R.; Marsh, R.; Price, A.R.; Ridgwell, A.J.; Shepherd, J.G. and The, GENIE Team (2006). Millennial timescale carbon cycle and climate change in an efficient Earth system model. Climate Dynamics, 26(7-8) pp. 687–711.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1007/s00382-006-0109-9
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Abstract

A new Earth system model, GENIE-1, is presented which comprises a 3-D frictional geostrophic ocean, phosphate-restoring marine biogeochemistry, dynamic and thermodynamic sea-ice, land surface physics and carbon cycling, and a seasonal 2-D energy-moisture balance atmosphere. Three sets of model climate parameters are used to explore the robustness of the results and for traceability to earlier work. The model versions have climate sensitivity of 2.8–3.3°C and predict atmospheric CO2 close to present observations. Six idealized total fossil fuel CO2 emissions scenarios are used to explore a range of 1,100–15,000 GtC total emissions and the effect of rate of emissions. Atmospheric CO2 approaches equilibrium in year 3000 at 420–5,660 ppmv, giving 1.5–12.5°C global warming. The ocean is a robust carbon sink of up to 6.5 GtC year−1. Under ‘business as usual’, the land becomes a carbon source around year 2100 which peaks at up to 2.5 GtC year−1. Soil carbon is lost globally, boreal vegetation generally increases, whilst under extreme forcing, dieback of some tropical and sub-tropical vegetation occurs. Average ocean surface pH drops by up to 1.15 units. A Greenland ice sheet melt threshold of 2.6°C local warming is only briefly exceeded if total emissions are limited to 1,100 GtC, whilst 15,000 GtC emissions cause complete Greenland melt by year 3000, contributing 7 m to sea level rise. Total sea-level rise, including thermal expansion, is 0.4–10 m in year 3000 and ongoing. The Atlantic meridional overturning circulation shuts down in two out of three model versions, but only under extreme emissions including exotic fossil fuel resources.

Item Type: Journal Article
ISSN: 1432-0894
Extra Information: Some of the symbols may not have transferred correctly into this bibliographic record and/or abstract.
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 6280
Depositing User: Users 2315 not found.
Date Deposited: 17 Jan 2007
Last Modified: 02 Dec 2010 19:56
URI: http://oro.open.ac.uk/id/eprint/6280
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