CFCs

Are today’s refrigerants safe?

March 21, 2025 By EarthWise Leave a Comment

Refrigeration is based on heat transfer mediums that absorb heat from the area being cooled and transfer it to the outside environment.

The earliest refrigerants were dangerous substances like ammonia. In the 1930s, chlorofluorocarbons (CFCs) like Freon became the standard refrigerant for use in refrigeration systems and even in aerosol cans. When these substances were found to be depleting the earth’s ozone layer, the Montreal Protocol dictated their phaseout and by the mid-1990s, CFCs were largely replaced by hydrofluorocarbons (HFCs).

HFCs don’t deplete the ozone layer, but they were eventually determined to be potent greenhouse gases, thousands of times more planet-warming than carbon dioxide. As a result, the global phaseout of HFCs began in 2016, and have been increasingly replaced by hydrofluoroolefins (HFOs), which are considered a more environmentally-friendly alternative to all their predecessors.

Trying to not be surprised by additional unpleasant discoveries about refrigerants, researchers are studying the potential environmental impacts of HFOs. Researchers at the University of New South Wales in Australia have found that HFOs can break down in the atmosphere and that some small amounts of the resultant products are in fact fluoroforms, which are the HFC with the greatest global warming potential and can stay in the atmosphere for up to 200 years.

That only a small amount of HFC gets into the atmosphere is good, but nevertheless it reveals that the consequences of replacing widely-used chemicals are not a simple matter to determine.

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Are our refrigerants safe? The lingering questions about the chemicals keeping us cool

Photo, posted July 19, 2021, courtesy of Vernon Air Conditioning via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The U.S. Ratifies A Climate Treaty | Earth Wise

October 14, 2022 By EarthWise Leave a Comment

In a rare display of bipartisanship, the U.S. Senate voted 69-27 in favor of ratifying a key international climate agreement aimed at curbing global warming. The Kigali Amendment to the Montreal Protocol, which has been ratified by 137 other countries so far, ends the use of climate-warming hydrofluorocarbons that are 1,000 times more potent than carbon dioxide in warming the atmosphere. This is the first international climate treaty that the U.S. has joined in 30 years.

The Kigali Agreement was established in Kigali, Rwanda in 2016 to phase out HFCs, which have been the replacements for CFCs (chlorofluorocarbons) in air conditioners and refrigerators. CFCs were found to be depleting the ozone layers that protects the earth from harmful ultraviolet rays. HFCs do not deplete the ozone layer, but they have been a significant contributor to global warming.

The U.S. ratification of the treaty is largely symbolic. The American Innovation and Manufacturing Act, passed by Congress in 2020, gave the EPA authority to regulate HFCs and the agency has already been doing so. However, the Senate action shows that the U.S. is back on the international climate bandwagon.

Failure to ratify the Kigali Amendment would have closed segments of the chemical and manufacturing industries to U.S. producers after 2023 because the Montreal Protocol prohibits trade with countries not party to it or its amendments.

Environmental advocates are hopeful that the U.S. can move forward on other climate actions. A next step would be to focus on methane, the second leading driver of climate change after carbon dioxide.

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Senate Votes to Ratify the Kigali Amendment, Joining 137 Nations in an Effort to Curb Global Warming

Photo, posted June 13, 2017, courtesy of UNIDO via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ozone Recovery Back On Track | Earth Wise

March 15, 2021 By EarthWise Leave a Comment

In 2019, we reported that new emissions of chlorofluorocarbons from eastern Asia were threatening the recovery of the ozone layer in the upper atmosphere. An unexpected spike in CFC emissions was threatening to undo the progress made under the Montreal Protocol, the international treaty under which every country in the world agreed to phase out the production and use of the ozone-eating chemicals by 2010.

In 2018, a team of scientists reported the spike in emissions of the particular formulation CFC-11 that began in 2013. By 2019, a second team reported that a significant portion of the emissions could be traced to the Shandong and Hebie provinces in China where there were small factories using the chemical to manufacture foam insulation used in refrigerators and buildings.

Recently, in two papers published in Nature, the same two research teams reported that the global annual emissions of CFC-11 into the atmosphere have declined sharply. They traced a substantial fraction of the global emission reductions to the very same regions of eastern China where they had previously reported the original spike.

The results are very encouraging. If CFC-11 emissions had continued to rise, or even just level off, there would have been real problems with ozone depletion. Two independent global monitoring networks – one operated by the National Oceanic and Atmospheric Administration and one led by MIT called the Advanced Global Atmospheric Gases Experiment – are doing a good job of detecting threats to the world’s protective ozone layer. However, the Chinese sources only accounted for about half of the CFC-11 entering the atmosphere. We still don’t know where the rest of it is coming from.

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Reductions in CFC-11 emissions put ozone recovery back on track

Return of an Old Threat

Photo, posted July 29, 2015, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why The Arctic Is Warming So Fast | Earth Wise

April 7, 2020 By EarthWise Leave a Comment

The Arctic has been warming at the fastest rate of any place on Earth. There have long been observations of amplification of Arctic warming, meaning that its temperature increases have been well above what would be expected from the global temperature rise.

Many climate models have attributed this warming to the melting of sea ice. As the bright white ice disappears for longer periods of the year, the dark surface waters that are exposed absorb sunlight rather than reflecting it back into space the way the ice does. This is known as the ice-albedo feedback. But it does not entirely explain the amount of warming in the Arctic.

Researchers at the Scripps Institution of Oceanography have developed a new theory that helps to explain what is going on.

In the areas of the Arctic Ocean where there is sea ice, the water is actually warmer at depth and colder near the surface. The deeper waters are fed by the relatively warm Pacific and Atlantic Oceans while the surface water is cooled by the ice. The increasing temperature difference between surface and deeper water causes a greater upward flow of heat. This was first observed in research cruises that revealed evidence that the Arctic Ocean water was becoming more turbulent over time.

According to computer modeling, this phenomenon is responsible for about 20% of the amplification of global warming that occurs in the Arctic.

There are multiple ongoing studies looking at the Arctic warming trend. Other factors that have contributed over time are the presence of chlorfluorocarbons in the atmosphere. That contribution is waning since the use of CFCs has been phasing out over time.

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Researchers Find New Reason Why Arctic is Warming So Fast

Photo, posted April 19, 2017, courtesy of Markus Trienke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate-Friendly Refrigerants

March 29, 2017 By EarthWise

In 1988, President Reagan signed the Montreal Protocol, which banned CFC refrigerants like Freon in air conditioners and refrigerators. The chlorofluorocarbons were the cause of a giant hole in the ozone layer, which has been shrinking ever since the ban. Unfortunately, the chemicals that replaced CFCs – hydrofluorocarbons or HFCs – have their own major problem: they are a seriously bad greenhouse gas, far worse than carbon dioxide. Last fall, an international agreement was reached by over 170 countries to reduce and eventually replace HFCs, which included 100 developing countries like China and India where air conditioning use is growing fastest.

The Shrinking Ozone Hole

August 2, 2016 By WAMC WEB

Researchers in Antarctica have been keeping watch on the infamous ozone hole over that continent for several decades. The Montreal Protocol on Substances that Deplete the Ozone Layer was a multinational agreement signed in 1987 designed to reduce the production and consumption of ozone depleting substances that enter the atmosphere. It has been amended in various ways on many occasions over the subsequent years.