When we think of the gases that contribute to climate change, carbon dioxide comes to mind first -- with good reason. CO2 accounts for about 82 percent of greenhouse gas emissions in the United States, and persists for centuries.
But other gases contribute to climate change as well, some of which are many times more potent than CO2 though less abundant in the atmosphere. One class of these is hydrofluorocarbons, or HFCs, gases used in many air conditioners and refrigerators. HFCs can be up to 10,000 times more damaging to the climate than CO2 -- and absent ambitious action to limit their use, HFC emissions are projected to triple in the U.S. by 2030.
Scaling back the use and production of HFCs is a critical part of fighting climate change, which is why the Obama Administration has made it a key component of its Climate Action Plan. Today, the White House announced new private-sector commitments and executive actions that will slash U.S. reliance on HFCs. Taken together with the actions announced by the White House and private sector last year, these actions will reduce cumulative global consumption of these greenhouse gases by the equivalent of more than 1 billion metric tons of CO2 through 2025.
Hydrofluorocarbons, which don’t deplete the ozone layer, became popular in the 1990s when they replaced the ozone-depleting gases phased out under the original and revised Montreal Protocol -- chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC). First signed in 1987 and updated continuously since then, the Montreal Protocol has proven tremendously effective at accomplishing its original goal -- repairing the ozone layer -- and is now seen as a model for international cooperation.
Now, many countries recognize the need to phase down HFCs through the Montreal Protocol, as well. However, a key technical concern that has arisen in negotiations over an amendment to the Montreal Protocol is whether low-global warming potential (GWP) refrigerants can perform as well under high-ambient-temperature conditions.
In response to this concern, the Department of Energy stepped forward and worked with Oak Ridge National Laboratory to assess how several low-GWP alternative refrigerants perform under high temperature conditions of up to 131°F. In particular, we focused on the performance of those alternatives in mini-split air conditioning units, given their prevalence in many developing countries. The testing program was guided by a panel of international technical experts from Brazil, China, Egypt, India, Italy, Japan, Peru, Saudi Arabia, and the U.S. Today, we released a report that summarizes the results of that testing program, showing that several viable replacements exist for both HCFC-22 and HFC-410A, two of the most common refrigerants.
It is our hope that these results can help inform the negotiations over an amendment to the Montreal Protocol at the upcoming Meeting of the Parties in Dubai in early November. With strong international action on HFCs, we can avoid up to 0.5°C of warming by the end of the century, substantially furthering our goal to limit global temperature rise.
The Energy Department is also working with industry and our National Labs to develop a new generation of heating and air conditioning technologies that will revolutionize how these technologies have operated for the past 100 years. These new technologies use alternative refrigerants that have either minimal or zero effect on the environment, while also cutting energy costs for businesses and homeowners. For example, one technology uses magnets to create the same cooling effect that traditional compressors do, but without the high greenhouse gas emissions. The concept has already been demonstrated in refrigerators and is now being applied to air conditioners.
Projects like these add to our existing efforts to develop commercially available low-GWP technologies, including alternative refrigerants and advanced supermarket refrigeration systems that don’t use HFCs.