News & Events

Grad student talk - Impacts of the permafrost carbon feedback on global climate

Thursday, February 26, 2015, 4:30PM - 5:30PM

Speaker

Elchin Jafarov

NSIDC postdoctoral scholar

Location:

RL-1 room 269

Permafrost-affected soils contain twice as much carbon as is currently in the atmosphere. Studies show that warming of the perennially frozen ground could initiate significant release of the currently frozen soil carbon into the atmosphere. To reduce the uncertainty associated with the modeling of the permafrost carbon feedback (PCF) it is important to start with the observed soil carbon distribution. We use available Northern Circumpolar Soil Carbon Dataset version 2 as an input for the soil organic carbon (SOC) in our carbon cycle model. I will present the results of that use after we equilibrated our model with the steady state climate forcing.

In this study we implemented new soil dynamic organic layer, dynamic root distribution and other improvements on the environmental factors affecting permafrost thermodynamics. Obtained results indicate that improved permafrost thermal dynamics allows better simulation of the observed SOC densities and their spatial distribution. We estimate potential temperature increases in Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections due to the PCF using published estimates of permafrost emissions and statistical estimates of individual model climate sensitivities. Our results indicate that the impact of the PCF on global temperature is proportional to the fraction of total carbon emissions that come from thawing permafrost.