© 2014 John Wiley & Sons Ltd. This is the peer reviewed version of the following article: Predicting ecosystem carbon balance in a warming Arctic: The importance of long-term thermal acclimation potential and inhibitory effects of light on respiration, Global Change Biology, Vol. 20 (6), pp. 1901–1912, 2014 which has been published in final form at http://dx.doi.org/10.1111/gcb.12549. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/WileyCDA/Section/id-828039.html)