In 2016, researchers at MIT and elsewhere observed the first indicators of healing in the Antarctic ozone layer. This environmental breakthrough was the result of decades of a concerted effort by almost every nation on the planet, which collectively agreed upon the Montreal Protocol. These nations promised to guard the ozone layer by eliminating the production of ozone-depleting chlorofluorocarbons, which are also strong greenhouse gases.
While the ozone layer is recovering gradually, researchers have discovered unexpectedly high emissions of CFC-11 and CFC-12, raising the opportunity of production of the prohibited chemical compounds that could be breach landmark global pact. Emissions of CFC-11 even confirmed an uptick around 2013, which has been traced mainly to a source in eastern China. New data recommend that China has now tamped down on illegal production of the chemical; however, emissions of CFC-11 and 12 are nonetheless bigger than anticipated.
Now MIT researchers have found that a lot of the present emission of these gases seemingly originates from massive CFC “banks”—old tools, including building insulation foam, fridges and cooling systems, and foam insulation, that was produced before the global phaseout of CFCs and is still leaking the gases into the environment. In line with the earlier analyses, scientists concluded that CFC banks would be too small to contribute very much to ozone depletion, and hence policymakers allowed the banks to remain.