Read the full story from NPR.
There’s a cycle that starts when the snow melts and the earth thaws high in Colorado’s Rocky Mountains. It’s a seasonal cycle based on timing and temperature, two variables that climate change is pushing increasingly out of sync.
To the outsider, it can be hard to see: Plants still grow, flowers bud, bears awake, and marmots breed. Broad-tailed hummingbirds still trill around a landscape that evokes the opening scene of The Sound of Music, with flowery meadows and granite peaks.
But those who know this ecosystem will tell you something is a little off. The flowers are blooming earlier. The marmots are mating in early May. Spring is springing sooner across the Northern Hemisphere, changing natural cycles around the world.
In Alaska, brown bears are changing their feeding habits to eat elderberries that ripen earlier.
In California, birds are nesting and breeding a week earlier than they did a century ago.