Because of a warming atmosphere, permafrost -- the frozen ground that covers the top of the world -- has been thawing rapidly over the last three decades. But there is cause for concern beyond the far north, because the carbon released from thawing permafrost could raise global temperatures even higher. "Changing Planet" is produced in partnership with the National Science Foundation.
Музыка
Фильмы
ТВ Шоу
Категории видео
