A US study found that expected changes in temperature and precipitation could lead to increases in net primary production in most rangelands. Animal production indicators increased in the north and decreased in the south based on current livestock types. The potential effect of climatic changes on dairy production varies indicated that the summer declines in milk production were greater than the current 1-in-10 year probability as well as those experience in the abnormally hot summer of 1980. However, the hardest hit operations may be those in the north, not currently adapted for summer production.