Climate Wire | Five ozone-depleting substances are increasing in the atmosphere despite international bans on their use and production, a new study finds.
The discovery puzzled and surprised scientists because chemicals are warming the planet. Their climate impact is equivalent to carbon emissions from a small country.
“We really don’t know where it’s coming from. It’s really a bit I’m scared.
A study published in the journal on Monday natural earth scienceshows an increase in emissions of five chlorofluorocarbons (CFCs) from 2010 to 2020.
CFCs are widely known to have destroyed the ozone layer in the Earth’s atmosphere throughout the 1980s. The five mystery CFCs have done little damage to the ozone layer, but their impact on climate is substantial, the study says. Equivalent to 10,000 tons of carbon dioxide.
That’s about 1.5 times London’s annual carbon footprint. It is also similar to the annual emissions of countries such as Switzerland and Sweden.
“Mitigating these emissions would have about as big an impact on the climate as a small country becoming carbon neutral,” said a senior scientist at the University of Bristol and NOAA’s Global Monitoring Institute. Study author Luke Western said.
CFCs were used in aerosol sprays and industrial refrigeration from 1989 until an international agreement known as the Montreal Protocol phased out their production and most uses. decades.
A 2010 update to the agreement prohibited the production of CFCs for the purpose of releasing them into the atmosphere. In theory, everything should have declined in the last decade.
However, CFCs can be used as raw materials in the manufacture of other chemicals, and can be released into the atmosphere in the process. CFCs can also be produced as a by-product of industrial processes.
Three of the CFCs identified in the new study are components or by-products in the production of ozone-friendly chemicals invented to replace them. These chemicals include certain hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs).
Both of these chemicals affect the climate. HFCs are powerful greenhouse gases and were targeted to be phased out in his 2016 update to the Montreal Protocol, known as the Kigali Amendment.
A supposedly climate-friendly alternative, HFO has been found to have a climate impact as CFCs are an ingredient in manufacturing and are leached during the manufacturing process.
“What we are suggesting here is that in producing these HFCs and HFOs, ozone-depleting CFCs may be released during the process, so there is some cost to ozone and the climate. It means it could take,” said Western.
Of the five CFCs identified in this study, the other two have no known uses. This makes it difficult to understand its origin and how to stop its emission.
This is not the first time a recent study has confirmed an increase in CFCs.A 2018 study published in Nature Chlorofluorocarbons, known as CFC-11, reported an increase since 2012. Scientists have since tracked emissions to several regions in Asia. About half of the increase is likely from eastern China and may be the result of unreported CFC production.
Recent studies indicate that these emissions have started to decline again in recent years.
Western said the new study underscores the importance of long-term monitoring, especially since ozone-depleting substances often affect the climate and the ozone layer.
Extensive surveillance networks in parts of the world, including Europe and North America, help scientists track CFC leaks. But in other regions, surveillance efforts are sparse, said study co-author Lyman.
“There are other parts of the world that are not as well covered, and it also sends the message that more measurements should be done in other parts of the world.”
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
