A new University of California report forecasts kick-to-the-gut climate-change realities for California farmers, especially those who grow permanent crops in the Central Valley. In a nutshell, the report anticipates big trouble ahead for crops such as almonds, peaches, table grapes, corn and rice. Scorching summer heat and longer periods of sustained drought will reduce yields. Higher temperatures also will provide a perfect incubator for insects and diseases. Some longtime Valley staples won’t be grown here at all. Ag is nimble in adapting to challenges.