Historical Land Cover Change during the Holocene: An Application of the UVic ESCM
Abstract
The University of Victoria Earth System Climate Model v. 2.9 (UVic ESCM) is used in this study to examine the role of anthropogenic land cover change (ALCC) in the Holocene carbon cycle. Three ALCC scenarios were developed by scaling data from Hyde 3.1 (Klein Goldewijk et al 2011). Additionally, we introduced a new parameterization of soil management and erosion associated with increased tillage and agricultural intensity into the model. The transient simulations, covering the period from 6000 B.C. to 2000 A.D., indicate that even very high anthropogenic land use fractions during the Neolithic and Bronze ages led to a small (3-5 ppm) contribution to atmospheric CO2 concentrations by 1 A.D., with a larger 10 ppm atmospheric CO2 increase obtained in the ALCC scenarios by the beginning of the Industrial Era. While only able to explain a small fraction of the pre-industrial CO2 trend, these figures are higher than in some previous studies. In addition, certain ALCC scenarios with lower per-capita land use in the mid-to-late Holocene had greater sedimentation than a simulation without ALCC, implying that more moderate deforestation scenarios may stimulate a decrease in ocean alkalinity rather than the expected increase. In addition, our results with the original Hyde 3.1 database suggest that lower per-capita land use could stimulate greater deep water formation in the North Atlantic and a relatively large (+0.10°C) increase in global temperatures by 1 A.D. This process reduced oceanic uptake of atmospheric CO2 in our simulations. Overall, however, all simulations indicate that a decrease in ocean alkalinity from other processes would be necessary to reduce the oceanic sink for the ALCC release and to promote an increase in atmospheric CO2 during the mid-to-late Holocene.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP11A1803S
- Keywords:
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- 4912 PALEOCEANOGRAPHY Biogeochemical cycles;
- processes;
- and modeling;
- 3344 ATMOSPHERIC PROCESSES Paleoclimatology;
- 1632 GLOBAL CHANGE Land cover change;
- 3337 ATMOSPHERIC PROCESSES Global climate models