Which of the following statements is true of "Earth’s Ozone Layer"?

JB: After 30 years of steady decline, Earth’s ozone layer is thinner but seems to be stable. A ban on ozone-depleting CFCs is largely responsible. Computer modeling gives reason to hope for an almost full recovery of Earth’s ozone layer within 60 years. But this sort of modeling is difficult -- and its predictions aren’t iron-clad.
DB: And some models show the ozone layer could face a new threat -- from global warming. Drew Shindell, an atmospheric scientist at NASA’s Goddard Institute for Space Studies in New York City, talked with us about his computer models of climate.