Sensitivity of carbon budgets to permafrost carbon feedbacks and non-CO2 forcings
The near proportionality between cumulative CO _2 emissions and change in near surface temperature can be used to define a carbon budget: a finite quantity of carbon that can be burned associated with a chosen ‘safe’ temperature change threshold. Here we evaluate the sensitivity of this carbon budge...
| Published in: | Environmental Research Letters |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
IOP Publishing
2015
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| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/10/12/125003 https://doaj.org/article/14d5354928e040889d3ad4bb2d198588 |
| Summary: | The near proportionality between cumulative CO _2 emissions and change in near surface temperature can be used to define a carbon budget: a finite quantity of carbon that can be burned associated with a chosen ‘safe’ temperature change threshold. Here we evaluate the sensitivity of this carbon budget to permafrost carbon dynamics and changes in non-CO _2 forcings. The carbon budget for 2.0 ${}^{\circ }{\rm{C}}$ of warming is reduced from 1320 Pg C when considering only forcing from CO _2 to 810 Pg C when considering permafrost carbon feedbacks as well as other anthropogenic contributions to climate change. We also examined net carbon budgets following an overshoot of and return to a warming target. That is, the net cumulative CO _2 emissions at the point in time a warming target is restored following artificial removal of CO _2 from the atmosphere to cool the climate back to a chosen temperature target. These overshoot net carbon budgets are consistently smaller than the conventional carbon budgets. Overall carbon budgets persist as a robust and simple conceptual framework to relate the principle cause of climate change to the impacts of climate change. |
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