translate English to French: CFCs have been manufactured since the middle of the last century and exhibited growing atmospheric concentrations until their use and release began to be curtailed by the MontrÃ©al Convention.
La fabrication des CFC remonte au milieu du siÃ¨cle dernier, et leurs concentrations atmosphÃ©riques ont augmentÃ© jusquâ€™Ã ce que le Protocole de MontrÃ©al en freine lâ€™utilisation et le rejet.