Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Cryospheric and Polar Processes Seminar

Committed Carbon Emissions and Global Warming due to the Permafrost Carbon Feedback by Yasin Elshorbany,  National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder



This talk is to discuss a study in which we quantify the increase in carbon emissions and temperature due to Permafrost Carbon feedback (PCF), defined as the amplification of anthropogenic warming due to carbon emissions from thawing permafrost. We use the Biosphere/Carnegie-Ames-Stanford Approach (SiBCASA) model to simulate the committed carbon emissions, the cumulative total emissions from thawing permafrost by 2300 for a given global temperature increase by 2100, while we use the PAGE-ICE (policy analysis for the greenhouse effect) integrated assessment model to simulate the nonlinear feedback of permafrost emissions on climate. Our results show, for the first time, that the PCF warming signal decrease by 2200 due to land and ocean uptake (which increase to reach its maximum as a result of accumulating carbon emissions), in contrast to previous results which show an increasing warming followed by an equilibrium. Committed warming, calculated using the PAGE-ICE climate emulator, for 2 ºC global warming are 0.14 by 2100 and 0.32 by 2300 (without land and ocean uptake). These values are reduced to 0.08 by 2100 and 0.09 by 2300 (with land and ocean uptake). Unlike Land uptake, which depends on annual fluxes, ocean uptake reaches its maximum feedback at a later time, since it depends on the cumulated carbon emissions. The RF logarithmic dependence on CO2 lead to a reduced impact of extra ton of CO2 on the RF, especially for higher emissions scenarios, contributing to the decline beyond 2200. These combined factors, in addition to the exhausted carbon stocks, lead to a decline in the PCF feedbacks after 2200, slowing the warming caused by the PCF. Non-linear SIAF lead to a further decline of the warming signal (compared to using constant SIAF) beyond 2200 for the high emissions scenarios.


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Wednesday, January 24, 2018
11:00 am to 12:00 pm




  • CIRES employees
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East Campus, RL-2, Room 155