HS-ESS2-6

Develop a quantitative model to describe the cycling of carbon among the hydrosphere, atmosphere, geosphere, and biosphere.

  1. Environment

    Ozone hits a new low

    Scientists discover a major thinning in the protective atmosphere over Arctic.

    By Stephen Ornes
  2. Humans

    A human migration fueled by dung?

    When people crossed from Asia to the Americas thousands of years ago, burning dung may have kept them warm.

    By Emily Sohn