EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Conditions for the Compost Bomb Instability

Joe Clarke, Paul Ritchie, and Peter Cox
Joe Clarke et al.
  • College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom (

Under global warming, soil temperatures are expected to rise. This increases the specific rate of microbial respiration in the soils which in turn warms the soil, creating a positive feedback process. This leads to the possibility of an instability, known as the compost bomb, in which rapidly warming soils release their soil carbon as CO2 to the atmosphere, accelerating global warming. Models of the compost bomb have exhibited interesting dynamical phenomena: excitability, rate induced tipping and bifurcation induced tipping. We examine models with increasing degrees of sophistication, to help understand the conditions that give rise to the compost bomb. We clarify the role an insulating moss layer plays and demonstrate that it has a 'most dangerous' thickness. We also use JULES, a land surface model, to examine where a compost bomb might occur and what affect other processes such as hydrology might have on the compost bomb.

How to cite: Clarke, J., Ritchie, P., and Cox, P.: Conditions for the Compost Bomb Instability, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9929,, 2020.


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