carbon dioxide CO₂

water vapor H₂O

methane CH₄

chlorofluorocarbons (CFCs)

Image A, because visible sunlight enters Earth’s atmosphere without being blocked by greenhouse gases.

Image A, because greenhouse gases block heat from leaving Earth’s atmosphere.

Image B, heat leaves Earth’s atmosphere without being blocked by greenhouse gases.

Image B, because greenhouse gases trap visible sunlight as it enters Earth’s atmosphere.

shoreline erosion

melting permafrost

growing ice sheets

stronger earthquakes

CFCs

water vapor (H₂o)

methane (CH₄)

carbon dioxide (CO₂)

Image X, because a relatively high concentration of greenhouse gases blocks more visible sunlight.

Image X, because a higher concentration of greenhouse gases absorbs more heat than image Y.

Image Y, because a lower concentration of greenhouse gases than Image X blocks less visible sunlight.

Image Y, because a lower concentration of greenhouse gases absorbs less heat than Image X.