Updates are available Erratum dated 2015-06-30

Article History

Received: 27 October 2014

Accepted: 19 March 2015

First Online: 27 April 2015

Change Date: 10 June 2015

Change Type: Erratum

Change Details: In the print and PDF versions of this Letter originally published, the last sentence of the paragraph concerning the double-deconvolution technique should have read: "The data therefore probably rule out a net decrease in organic land carbon stocks between 755 and 1850 CE." In addition, a paper by Schuur et al. was not included in the reference list, and should have been cited as ref. 29 in the following sentence: "Permafrost carbon is also a plausible source of CO2 to the atmosphere during intervals of elevated Arctic temperature29, but would require re-expansion of permafrost into previously active soils during cold intervals to act as a sink for CO2." The remaining references have been renumbered to accommodate this addition. These errors have been corrected in the PDF version. 29. Schuur, E. A. G.et al.Climate change and the permafrost carbon feedback.Nature520, 171–179 (2015).

Competing interests

: The authors declare no competing financial interests.