Nature Geoscience 9, 111–115 (2016); published online 25 January 2016; corrected after print 28 January 2016.

In the original version of the Letter originally published, the sentence comparing the authors' results to those of previous studies was missing a citation and it should have read: 'Our results of per-capita NFPs are higher than those presented in previous studies3,11–13 — for example 62 kg cap−1 yr−1 for the USA compared to 41 kg cap−1 yr−1 (ref. 3)...'. This has been corrected in the online versions of the Letter.