What does a model of the carbon cycle show? (1 point)
• The amount of Earth's carbon is constant.
• The amount of Earth's carbon increases.
• The amount of Earth's carbon decreases.
• The amount of Earth's carbon cannot be determined
• The amount of Earth's carbon is constant.
• The amount of Earth's carbon increases.
• The amount of Earth's carbon decreases.
• The amount of Earth's carbon cannot be determined