To phase out these damaging gases, Canada and Mexico have joined the United States in proposing to expand the scope of the international treaty governing ozone depletion.
The proposal would phase down production and use of the gaseous refrigerants known as hydrofluorocarbons, HFCs, which are "a significant and rapidly growing contributor to climate change," the U.S. EPA said in a statement Thursday.
The gases now used to keep food frozen are damaging to the Earth's climate. (Photo by Jordan Dawe)
HFCs are up to 14,000 times more damaging to the Earth's climate system than the most prevalent greenhouse gas carbon dioxide, scientists have found.
The EPA led the analysis in the proposal, which demonstrates environmental benefits equal to removing greenhouse gas emissions from 59 million passenger cars each year through 2020, and 420 million cars each year through 2050.
On April 29, the United States, Mexico, and Canada together submitted a proposed amendment to phase down HFC consumption and production under the Montreal Protocol on Substances that Deplete the Ozone Layer.
Signed in 1987, the Montreal Protocol is a treaty with 196 countries to help restore the ozone layer by ending the production of ozone-depleting substances and now potentially phasing down HFCs.
"Canada and its partners are demonstrating global leadership and commitment to proactively avert a potential threat to the climate system," said Canada's Environment Minister Jim Prentice. "Having played a key role in the negotiation and evolution of the Montreal Protocol, the Government of Canada is eager to build on its achievements and recognizes the significant impact this amendment would have on global climate change mitigation."
During the phaseout of the ozone depleting refrigerant gases chlorofluorocarbons, CFCs, under the Montreal Protocol and the Clean Air Act, manufacturers of equipment such as car air conditioners and kitchen refrigerators substituted HFCs.
However, the HFCs that were presented as the environmental alternative to CFCs by chemical companies have had a warming impact on the climate.
CFC use has decreased, but HFCs are widely used in air conditioning, the manufacturing of electronics and appliances, and for tracking leaks in natural gas lines.
Even though efforts over the past decade have reduced emissions, global atmospheric concentrations of HFCs continue to increase, according the the EPA.
Without this proposal, HFC use in developing countries is anticipated to grow substantially, driven both by increased demand for refrigeration and air-conditioning and because HFCs were developed as alternatives to ozone depleting substances.
Substitute chemicals and technologies are available. The EPA is proposing four refrigerants as possible substitutes for use in U.S. household and commercial refrigerators and freezers.
The proposal lists isobutane, propane, HCR-188C, and HCR-188C1 as potentially acceptable substitutes for the ozone-depleting chemicals CFC-12 and HCFC-22. The EPA says these hydrocarbon-based coolants could replace existing refrigerants that harm the stratospheric ozone layer and the climate system.
Globally, hydrocarbon refrigerants have been in use for over 10 years in countries such as Germany, the United Kingdom, Australia, and Japan.
In Europe and Asia, equipment manufactures have designed and tested household and commercial refrigerators and freezers to explore flammability and safety concerns associated with using hydrocarbon refrigerants.
A Greenfreeze refrigerator (Photo courtesy Greenpeace)
Due to the fact that hydrocarbon refrigerants have zero ozone depletion potential and very low global warming potential, many companies are interested in using hydrocarbon refrigerants in the United States as well.
The proposed amendment, which builds on a proposal last year, updates the step-wise HFC phasedown schedule for both developing and developed countries.
Greenpeace, too, has been working to eliminate the use of HFC by developing an alternative "Greenfreeze" refrigerator that does not use the potent greenhouse gases HFCs and HCFCs but instead uses natural refrigerants, and by persuading the private sector to adopt this technology. Developed in 1992, Greenfreeze technology has come into mainstream use with 40 million units sold worldwide in over 100 models by 2000.
Natural refrigerants are naturally occurring substances, such as the hydrocarbons propane and isobutane, two of the four substitutes now proposed by the U.S. EPA, as well as carbon dioxide, a beneficial use for the greenhouse gas that is damaging when released into the atmosphere.
Last December, The Coca-Cola Company and its bottling partners announced that 100 percent of their new vending machines and coolers will be HFC-free by 2015.
The transition to HFC-free refrigeration will reduce the equipment's direct greenhouse gas emissions by 99 percent, the company said.
"Climate change is real and the time to act on solutions is now," said Muhtar Kent, chairman and CEO of The Coca-Cola Company in December. "Greenpeace has played a critical role in raising our awareness about the need for natural refrigeration. Our announcement today demonstrates a commitment to use our influence in the marketplace to drive innovation and help shape a low-carbon future."
"We welcome Coca-Cola's commitment to help tackle climate change," said Kumi Naidoo, executive director, Greenpeace International. "Large enterprises have both an opportunity and responsibility to change the game and Coca-Cola's action leaves no excuse for other companies not to follow."
More information on the trilateral proposal: http://www.epa.gov/ozone/intpol/mpagreement.html
More information on the four replacement chemicals: http://www.epa.gov/ozone/snap/
The public is invited to provide comments on the EPA rulemaking for this proposal to docket number EPA-HQ-2009-0286 at: http://www.regulations.gov/
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