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Class of 'Super GHGs' Becoming Focus of Heightened Concern

By David Sassoon

Apr 28, 2009
chill over greenhouse gases

The growing global demand for air-conditioning and refrigeration – humanity's need to cool things off – is ironically now emerging as one of the biggest potential contributors to future global warming.

A class of gases known as HFCs – hydrofluorocarbons – used by the refrigeration industry to cool people in their cars and homes and to keep food from spoiling, is turning out to be the primary culprit.

Developed to replace the gases responsible for depleting the ozone, HFCs have a powerful worsening effect on global warming and have created another challenge for lawmakers to confront, an emergency within an emergency.

Each molecule of these man-made gases, often called F-gases, has a global warming potential (GWP) than a molecule of CO2, thus earning them the nickname "super GHGs."

New projections indicate that unless these gases are rapidly phased out with available alternatives that are benign by comparison, they could negate the impact of all other emissions reductions efforts now being contemplated. By 2040, the international NGO Environmental Investigation Agency estimates HFCs will have added 180 gigatons CO2 equivalent to the atmosphere.

"If we control these gases internationally, we will prevent the release of the equivalent of 25 years of total U.S. emissions" said S.F. LaBudde, campaign director at the Environmental Investigation Agency. "It could hinge on getting the HFC provisions of the Waxman-Markey bill right."

The Waxman-Markey bill, the framework national climate legislation now working its way through the House, contains provisions for the phase out of HFCs, but LaBudde says it provides very little incentive for the U.S. refrigeration industry to reduce production levels.

The draft provisions set a high ceiling on acceptable production levels and allow industry to bank unused allowances for future use. That means there is no real downward pressure for industry to switch to alternatives. Industry gets to start off with a lot of extra breathing room and to push that bubble of air forward for years without the need to take urgent action. LaBudde warns that this built-in cushion delays action 10 or 15 years into the future, time which the science says we simply do not have.

The U.S. State Department is engaging on the HFC issue on the international stage through its involvement with the Montreal Protocol, the international agreement now more than 20 years old that has successfully created a global regime for the control of ozone-depleting substances.

There is widespread recognition that use of refrigerants will skyrocket in developing nations in coming decades, and that an amendment to the Montreal treaty is urgently needed to set the world on the right path.

Complicating the circumstance, however, is an inadvertent outcome of the success of the Montreal Protocol: It has accelerated a switch away from refrigerants that deplete the ozone to refrigerants with high global warming potential – the super GHGs. The State Department and EPA are getting behind efforts to amend the Montreal agreement. The idea is to allow the Montreal mechanism – which is established and effective – to assist in the phase out of HFCs in order to protect the climate.

That extension of the Montreal treaty's authority into the climate change arena is ruffling some political feathers in Washington, and the interagency process within an administration still finding its feet is slowing down US action. 

"It's totally irrational not to use the Montreal Protocol. This step of getting an amendment is vital, absolutely essential," said Alexander von Bismarck, executive director of the Environmental Investigation Agency.

The astronomical potential of HFCs to worsen global warming came to worldwide attention in an article published in 2007 in the (PNAS). One of the primary substitute gases the industry started to use beginning in 1990 is HFC-134a, a super GHG with global warming potential 3,830 times that of CO2 and an atmospheric lifetime of 14 years. Other gases in the same HFC class have also been developed, including HFC-23, which has a GWP almost 12,000 times greater than CO2, and a lifetime in the atmosphere of 270 years.

Some industry players are poised to lead the way to substitutes that will not worsen global warming. Both and are promoting a product called 1234-YF which they are touting as a replacement for the super GHGs used in automobile air conditioning systems. In testimony before the House Energy and Commerce Committee last week, Dupont Board Chairman Chad Holliday talked up the product:

Global Warming

Maybe Americans can pass a law to resort to solar vehicles, if we have money for alcohol, cosmetics, fashion, and other leisure products, then we have money for the solar vehicle.

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