Barrons AP Environmental Science

(Marvins-Underground-K-12) #1

  1. (E) Concentrations of ozone-depleting chlorofluorocarbons (CFCs) have
    leveled off in the stratosphere and have actually begun to decline in the
    lower atmosphere. A CFC molecule can take about 8 years after being
    released at ground level to reach the stratosphere. Decades may pass until it
    is converted by sunlight into a form that depletes ozone.

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