Upside to Drought: Gorgeous Fall Leaves Less water leads to less chlorophyll and more colors By Dustin Lushing, Newser Staff Posted Sep 2, 2012 4:15 PM CDT Updated Sep 3, 2012 10:05 AM CDT 9 comments Comments Less water means less chlorophyll means more colors. (Shutterstock) (Newser) – The lack of rain this year could elicit a dazzling side effect in the fall: exceptionally colorful leaves. That's because below-average rainfall in the Northeast may cause trees to shut down production of a chemical called chlorophyll earlier than usual. Without it, various pigments like carotenes and xanthophyll (yellow to orange) and anthocyanins (red) visually emerge, reports LiveScience. Water scarcity causes stress in trees, which leads to an earlier-than-usual preparation for winter and the switch-off of chlorophyll. The fall display will still be vivid as long as days are sunny and nights cool, says a researcher, but a particularly harsh drought will make leaves die and break off. It's a bit early to tell just how spectacular the arboreal show will be this year because the colors are not at their pinnacle until October.