Review status: this preprint was under review for the journal ACP but the revision was not accepted.
Future biogeochemical forcing in Eastern Siberia: cooling or warming?
A. Arneth1,S. Olin2,R. Makkonen3,P. Paasonen3,T. Holst2,M. Kajos3,M. Kulmala3,T. Maximov4,P. A. Miller2,and G. Schurgers2A. Arneth et al.A. Arneth1,S. Olin2,R. Makkonen3,P. Paasonen3,T. Holst2,M. Kajos3,M. Kulmala3,T. Maximov4,P. A. Miller2,and G. Schurgers2
1Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research/Atmospheric Environmental Research, Garmisch Partenkirchen, Germany
2Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 22362 Lund, Sweden
3Department of Physics, University of Helsinki, P.O. Box 64, 00014 University of Helsinki, Finland
4Department of Plant Ecological Physiology and Biochemistry Lab., Institute for Biological Problems of Cryolithozone SB RAS, 41, Lenin ave, Yakutsk 677980, Russia
1Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research/Atmospheric Environmental Research, Garmisch Partenkirchen, Germany
2Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 22362 Lund, Sweden
3Department of Physics, University of Helsinki, P.O. Box 64, 00014 University of Helsinki, Finland
4Department of Plant Ecological Physiology and Biochemistry Lab., Institute for Biological Problems of Cryolithozone SB RAS, 41, Lenin ave, Yakutsk 677980, Russia
Received: 24 Jun 2014 – Accepted for review: 30 Jun 2014 – Discussion started: 22 Jul 2014
Abstract. Over-proportional warming in the northern high latitudes, and large carbon stocks in boreal and (sub)arctic ecosystems have raised concerns as to whether substantial positive climate feedbacks from biogeochemical process responses should be expected. Such feedbacks occur if increasing temperatures lead to e.g., a net release of CO2 or CH4. However, temperature-enhanced emissions of biogenic volatile organic compounds (BVOC) have been shown to contribute to a cooling feedback via growth of secondary organic aerosol (SOA), and related aerosol forcings. Combining measurements in Eastern Siberia with model-based estimates of vegetation and permafrost dynamics, BVOC emissions and aerosol growth, we show here that the additional climate forcing from changes in ecosystem CO2 balance and BVOC-SOA interactions nearly cancel on a regional scale. The interactions between emissions and vegetation dynamics that underlie individual forcing estimates are complex and highlight the importance of addressing ecosystem-climate feedbacks in consistent, process-based model frameworks that account for a multitude of system processes.