In his encyclical on the environment, Pope Francis devotes a section to genetic modification (GM) of crops and livestock. “The risks involved are not always due to the techniques used, but rather to their improper or excessive application,” says the pope. “Although no conclusive proof exists that GM cereals may be harmful to human beings, and in some regions their use has brought about economic growth which has helped to resolve problems, there remain a number of significant difficulties which should not be underestimated. In many places, following the introduction of these crops, productive land is concentrated in the hands of a few owners” to the detriment of small producers. The pope suggests “a broad, responsible scientific and social debate needs to take place …. This is a complex environmental issue.”