The weakened ozone layer, which is vital to protecting life on Earth, is on track to be restored to full strength within decades — the latest success of a global effort by nations to stop using chemicals that had been destroying the critical layer in the upper atmosphere.The amended timeline of Earth’s history would officially recognize that humankind’s effects on the planet had been so consequential as to bring the previous geologic period to a close.The Chinese CFC-11 was very likely used as a blowing agent in making foam insulation.During foam production, some of the CFC-11 escapes into the atmosphere, where it can be detected and measured, but much of it is contained within the foam as it hardens.Durwood Zaelke, president of the Institute for Governance & Sustainable Development, a Washington-based research and advocacy organization, said the elimination of the rogue emissions was another example of the success of the protocol, which is generally considered to be the most effective"