The News story ‘Cancelled project spurs debate over geoengineering patents’ ( Nature 485, 429; 2012) implied that the Oxford Principles were produced in 2011. In fact, they were drawn up in 2009 before the Asilomar climate conference. The Editorial ‘A charter for geoengineering’ ( Nature 485, 415; 2012) wrongly gave the date for the Asilomar meeting as 2009 instead of 2010.