Enormous herds of animals roamed the Arctic tundra thousands of years ago. Just a fraction remain today, but some scientists say they should be brought back to help fight climate change. Wild horses, ...

For nearly two decades, scientists have noted dramatic changes in arctic tundra habitat. Ankle-high grasses and sedges have given way to a sea of woody shrubs growing to waist- or neck-deep heights.

Regina Bailey is a science writer, educator, and board-certified registered nurse. Her work has been featured in "Kaplan AP Biology" and "The Internet for Cellular and Molecular Biologists." Biomes ...