CFCs were banned in Montreal in 1987.
The effects of CFCs might go beyond the ozone layer. CFCs are potent greenhouses gases and could have a broader impact on climate change outcomes. CFCs are found in relative concentrations in the atmosphere when compared to carbon dioxide, so they’re considered a minor player in global warming.
While CFCs don't seem to cause global warming, a different picture emerges with regional warming. Recent research has shown that these same gases have sped up the warming of the Arctic, contributing to a sea level rise and surface warming in the North Pole.
Maybe a 'minor player', but a contributing factor, it seems.
Over time, the protocol has been updated to include more substances that could cause harm to the ozone layer and the climate. For example, in 2016, hydrofluorocarbons were added to the list of controlled substances, because these gases have been identified as potent greenhouse gases. The treaty is considered to be one of the most successful protocols to tackle an environmental challenge caused by humans.Are we now conflating the 1987 ozone agreement with subsequent concern over CO2? Greta would be proud!
Although the gases have been banned, they're not gone for good. Stephen Montzka, a research chemist at the NOAA, says they've detected possible illegal CFCs in the atmosphere. In 2018, Montzka coauthored a report in Nature that showed unexpected levels of CFC-11, a type of chlorofluorocarbons, were present. This concentration of CFC-11 was perhaps the result of unauthorized industrial production, going against the Montreal Protocol.
Did someone say China? Other third-world countries? Countries that signed the Paris Accord to limit man-made global climate change Who will tell Greta?
Note: A much shorter version of this November, 2020 article appeared in the June, 2021 issue of Discover Magazine.