In response to the Letter to the Editor from Russell Paterson (2011), the remit of our paper (Magan et al., 2011) was to cover aspects which were not already covered in the Paterson & Lima (2010) review. They do refer to CO2 on pages 1904 and 1906, in relation to plant diseases, and on page 1911 it is mentioned briefly under Section 4: Challenges in predicting climate change. However, in Section 3: Mycotoxigenic fungi and mycotoxins (pages 1906–1911), they never mention CO2 in their review at all. The impact of CO2, in the context of climate change, in relation to plant diseases and epidemiology is very well covered by other papers in the Plant Pathology special issue (volume 60 issue 1). Thus, we believe that our approach to these issues adds to the information already available and hopefully gives a perspective where integration of molecular, ecological and modelling approaches can be used to determine relative risk of mycotoxin problems in the context of the food security agenda and climate change.