On the streets of Manhattan and Washington, D.C., in neighborhoods in Seoul and parks in Paris, ginkgo trees are gradually losing their bright yellow leaves in reaction to the first bout of frigid winter air.

This leaf drop, gradual at first, and then suddenly, carpets streets with golden, fan-shaped leaves every year. But around the world, scientists are documenting evidence of the event happening later and later, a possible indication of climate change.

“People would ask us, ‘When should I come out to see peak ginkgo color?’ and we would say the 21st of October,” says David Carr, the director of the University of Virginia’s Blandy Experimental Farm, which is home to The Ginkgo Grove, an arboretum with over