text: Following the unanimous ratification of the 1987 Montreal Protocolin response to concerns about the role of concentrations of chlorofluorocarbons (CFCs) in ozone layer-depletion in the stratospherea process was put into place to gradually phase out and replace CFC-13 and all the other CFCs. Research in the 1980s said that these man-made CFC compound compounds had opened a hole in ozone layer in the upper atmosphere or stratosphere that protects life on earth from UV radiation. 
  CFC-13s ozone depletion potential (ODP) is high 1 (CClF = 1)it is categorized as a Class I in the IPCCs list of ozone-depleting substances. CFC-13's radiative efficiency is high which results in a high global warming potential (GWPs) of 13 900 GWP-100 yr that is "surpassed by very few other greenhouse gases." It is categorized as a Class I in the list of ozone-depleting Substances.