Abstract
Using a coupled climate-carbon cycle model, fossil fuel carbon dioxide (CO(2)) emissions are derived through a reverse approach of prescribing atmospheric CO(2) concentrations according to observations and future projections, respectively. In the second half of the twentieth century, the implied fossil fuel emissions, and also the carbon uptake by land and ocean, are within the range of observational estimates. Larger discrepancies exist in the earlier period (1860-1960), with small fossil fuel emissions and uncertain emissions from anthropogenic land cover change. In the IPCC SRES A1B scenario, the simulated fossil fuel emissions more than double until 2050 (17 GtC/year) and then decrease to 12 GtC/year by 2100. In addition to A1B, an aggressive mitigation scenario was employed, developed within the European ENSEMBLES project, that peaks at 530 ppm CO(2)(equiv) around 2050 and then decreases to approach 450 ppm during the twenty-second century. Consistent with the prescribed pathway of atmospheric CO(2) in E1, the implied fossil fuel emissions increase from currently 8 GtC/year to about 10 by 2015 and decrease thereafter. In the 2050s (2090s) the emissions decrease to 3.4 (0.5) GtC/year, respectively. As in previous studies, our model simulates a positive climate-carbon cycle feedback which tends to reduce the implied emissions by roughly 1 GtC/year per degree global warming. Further, our results suggest that the 450 ppm stabilization scenario may not be sufficient to fulfill the European Union climate policy goal of limiting the global temperature increase to a maximum of 2A degrees C compared to pre-industrial levels.
Item Type: | Journal article |
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Faculties: | Geosciences > Department of Geography > Physical Geography and Land Use Systems |
Subjects: | 900 History and geography > 910 Geography and travel |
ISSN: | 0165-0009 |
Language: | English |
Item ID: | 68518 |
Date Deposited: | 22. Aug 2019, 12:38 |
Last Modified: | 04. Nov 2020, 13:50 |