Agence France-Presse: The protective ozone layer in the earth’s upper atmosphere has stopped thinning and should largely be restored by mid century thanks to a ban on harmful chemicals, UN scientists said on Thursday. The quot;Scientific Assessment of Ozone Depletion 2010quot; report said a 1987 international treaty that phased out chlorofluorocarbons (CFC) — substances used in refrigerators, aerosol sprays and some packing foams — had been successful. Ozone provides a natural protective filter against …