In the Southeast, we are observing changes to the water cycle as temperatures increase. We see both more intense rainfall events and more droughts. California is also seeing this and observing that the changes in climate are also leading to changes in pests and diseases, which the farmers there treat with pesticides and herbicides. But the increases in heavy rains are leading to more runoff; that puts heavier loads of chemicals into streams and groundwater. Reducing this requires changes to the way crops are managed so that the water is not made more toxic. The longer growing season also leads to the need for more pesticide use, which can add to the problem. You can read about California’s experience with this trend at Inside Climate News.