Droughts that cause leaves to turn brown and wither before they can reach peak color. Heat waves prompting leaves to fall before autumn even arrives. Extreme weather events like hurricanes that strip trees of their leaves altogether. For a cheery autumnal activity, leaf peeping is facing some serious threats from the era of climate change. Leaf peeping, the practice of traveling to watch nature display its fall colors, is a beloved annual activity in many corners of the country. But recent seasons have been disrupted by weather conditions, and the trend is likely to continue as the planet warm...