USA. California. Harvesting grapes from 100 year old vines on the Pagani ranch near Kenwood. Calfornia is now one of the world's great wine-producing regions with grapes ranking third among the state's top farm products. Grossing nearly US$3 billion in sales in 1997. Among the climate change predictions from scientists is that California's wine-growing region will soon be too warm to grow grapes. 2004.