Some older applications still in use may emit more CFCs than previously estimated, according to a climate science study published on the 17th in the journal Nature communications. These emissions may delay the recovery of the Antarctic ozone hole and release the equivalent of 9 billion metric tons of CO2 into the atmosphere. At present, it is believed that there are still many uncertainties in the emission level and change trend, and the source of the new emissions found previously has not been found.

Since the entry into force of the Montreal Protocol in 1987, scientists have predicted that the ozone hole in Antarctica will return to its pre loss level in the second half of the 21st century. China acceded to the Vienna Convention for the protection of the ozone layer in September 1989 and the protocol in June 1991. In the past 30 years, it has achieved the goal of implementing the protocol at all stages as scheduled. As of May 2019, the number of ODS eliminated in China accounts for more than half of that in developing countries.

According to the protocol definition, most countries have agreed to stop using CFC in production. However, the emissions of the products already in use (CFC Library) are still continuing. These products include some chillers, air conditioners and insulation foam. This time, Megan rickley and his colleagues, researchers at MIT, used a new statistical framework to assess the size of the CFC pool and the corresponding emissions of CFC-11, CFC-12 and CFC-113. The results show that these emissions are much higher than those shown in the previous assessment, accounting for a large part of the current estimated emissions of CFC-11 and CFC-12 (excluding the increased emissions of CFC-11 due to the resumption of production after 2012).

Although the protocol allows the continued use of CFC-113 in some applications, the emission levels reported here exceed those reported in previous studies. According to the team's estimate, the current emissions from these reservoirs may delay the recovery of the ozone hole for six years and release the equivalent of 9 billion metric tons of CO2 into the atmosphere.

The latest results highlight the need to recycle and destroy CFC repositories to reduce emissions, according to the researchers. At the same time, the recent discovery of unexpected increase in CFC-11 emissions and the failure to identify the source indicate that it is necessary to quantify the emissions of these reservoirs in order to accurately assess the scale of emissions caused by the resumption of production.

Editor in chief circle

When we found the ozone hole over Antarctica, we were shocked. No one thought that the tiny human beings have such great destructive power, and the earth's umbrella is so fragile. Since then, we have begun to reflect and act. We have replaced cheap air-conditioners and fridge refrigerants, limiting the insulation of foams. Soon, the ozone layer is recovering, which is gratifying. However, in the past few years, there have been danger signs. Environmental protection should be our lifelong career, and we should not be careless.

Source: Science and Technology Daily