There is no overall consensus as to whether anthropogenic climate change will increase or decrease global agricultural potential. Negative impacts could be experienced at the regional level as a result of changes in weather, moisture availability (Parry, 1990), pests associated with climate change (EPA, 1989) and changes in ground level ozone associated with pollutants. Areas of existing vulnerability, including SE Asia, the Sahel in N. Africa and parts of South America, may experience the most severe effects (UNEP, 1989). Parts of the high and mid latitudes may see increases in potential productivity as the length of the growing season expands, but this is likely to be confined largely to the Northern Hemisphere (Parry & Carter, 1988; Parry et al., 1989).
On balance, global food production may be maintained at or near present day levels (Rosenzweig et al., 1994); however, the cost of achieving this is unclear, especially in view of a rapidly growing world population.