A significant portion of the world's emissions of heat-trapping gases emitted by air conditioners, refrigeration and other applications comes from the developing world, finds a new study in the Proceedings of the National Academy of Sciences.
In addition, developed nations are making mistakes when reporting emissions of the gases, called hydrofluorocarbons, or HFCs, to the U.N. Framework Convention on Climate Change (UNFCCC), the study finds.
The study follows international negotiations last week in Bangkok, Thailand, where nations discussed the phaseout of HFCs under the Montreal Protocol, a global treaty meant to protect the planet's ozone layer. Since the protocol was set up in 1987, emissions of ozone-damaging chemicals like HCFCs have fallen drastically.
But, unexpectedly, the chemicals have been replaced with HFCs, which are potent, short-lived greenhouse gases with global warming potentials hundreds to thousands of times that of carbon dioxide. Nations are scrambling to curb HFC emissions under the Montreal Protocol, which would equal the climate benefits of removing 30 billion cars by 2050.
In recent years, global air monitoring networks have shown rising levels of HFCs in the atmosphere, but developed nations claim responsibility for 60 percent of those emissions.
This means one of two things: Developed nations are underreporting their emissions, or developing nations -- which do not report their HFC emissions to the United Nations -- are making up the gap.
The PNAS study finds that the latter is the case.
"The bottom line of the new paper is that the very large gap in reported HFC emissions is from developing countries," said Durwood Zaelke, president of the Institute for Governance and Sustainable Development (IGSD), who was unaffiliated with the study.
Offsetting renewable benefits with air conditioners
The study, led by Mark Lunt at the University of Bristol, used observations from two global air monitoring networks to calculate HFCs emitted by nations or regions.
The world emitted 468 million metric tons of carbon dioxide equivalents (CO2e) of HFCs in 2012, up from 303 million metric tons CO2e in 2007, the study finds.
Developed nations accounted for about 60 percent of the 2012 emissions. The rest came from the developing world, the study finds, and these emissions are growing at a fast clip.
"Emissions from [developing] countries are not quite as much as the [developed] countries," Lunt said, "but they are growing faster."
The East Asia region -- China and South Korea, in particular -- accounted for 33 percent of developing world emissions, the PNAS study finds.
The scientists found it difficult to track emissions from India because of the dearth of air observation towers nearby.
The rise of air conditioning and refrigeration in the hot, tropical climes of the developing world has led to the growth in HFC emissions.
Almost all Chinese-owned air conditioners by 2005 and sales in other parts of the world have skyrocketed, according to a presentation given at the Bangkok talks by Nihar Shah, a senior scientific engineering associate at the Lawrence Berkeley National Laboratory.
The trend is detrimental to the climate not only because of HFC impacts -- air conditioners also significantly draw electricity. Shah estimated that as people install home air conditioners in poorer nations, the units would consume half or more of the new solar and wind capacity nations install by 2020.
Air conditioner units could be improved to become more energy-efficient and avoid HFCs, which would double climate benefits, Zealke of IGSD said.
"This is a very important point for India, China and indeed all countries," he said. "Improving AC efficiency pays a big bonus for climate, as well as taking pressure off electric grid and reducing AC operating cost for consumers."
Wealthy nations mix up HFC numbers
The PNAS study finds that developed nations have to improve their accounting of HFC emissions to UNFCCC, as well.
There are many types of HFCs, and some are worse for the climate than others. HFC-134a is the most abundant. Other HFCs include HFC-32, HFC-125, HFC-143a and HFC-152a.
When Lunt and his colleagues examined individual HFC emissions reported by rich nations to the United Nations, they found inaccuracies. Nations were overestimating HFC-134a levels and underestimating the other types of emissions.
Fortuitously, when the HFCs were aggregated together, the inaccuracies corrected each other in such a way that UNFCCC had an accurate picture of overall emissions from the developed world.
But the details would matter as nations consider how to phase out HFCs under the Montreal Protocol, Lunt said.
Most nations support an HFC phaseout, and diplomats discussed such an agreement in Bangkok last week.
India, for the first time, agreed to discuss HFC curbs this month (ClimateWire, Apr. 17). China, Brazil and 54 African nations are also on board.
The holdouts are a consortium of primarily oil-producing -- and extremely hot -- nations, led by Saudi Arabia, according to the Natural Resources Defense Council.
However, the Saudis' grip might be loosening, according to NRDC, and further progress is expected at negotiations to be held in Paris in July.
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