With the rising atmospheric carbon dioxide concentration [CO 2], crops will assimilate more carbon. This will increase yields in terms of carbohydrates but dilute the content of protein and minerals in crops. This consequential life cycle assessment study modelled the environmental consequences that such altered chemical composition and crop yields would have for the production of pig feed. Results revealed, among others, that an extra European demand of pig feed under an atmospheric [CO 2] of 550 mole mole -1 would lead to ca. 6% less expansion of additional arable land worldwide, in comparison to feed produced under today's conditions. However, this did not translate into lower greenhouse gas emissions, because the benefit of increased crop yield was counteracted by changes in the composition of the feed formulation. Among the important changes, feed produced under high [CO 2] was shown to integrate 23% more soymeal and 5% less wheat than at present.
