Fast growing HFC levels risk undermining climate benefits of HCFC phase out

As the international community celebrates the International Day for the Preservation of the Ozone Layer, today (16 September) is a fitting moment to evaluate progress regarding reversal of the ozone layer depletion, but also to assess the impact that replacement substances are having on the climate. The Scientific Assessment of Ozone Depletion 2014, a report released on 10 September, provides some interesting insights on this topic.

Rise of HFCs, an ‘unintended’ consequence of Montreal Protocol activities

The good news is that the ozone layer is slowly recovering and should reach 1980 benchmark levels across most of the globe mid-century, as a result of activities under the Montreal Protocol. On the other hand the same activities have lead to HFC emissions growth, whose rapid increase is threatening to strongly contribute to climate change and undermine the efforts of the Montreal Protocol.

“The Montreal Protocol has shown that decisive action by the international community, including the private sector, can achieve transformative results for the common good. Let us learn from this example and apply its lesson to the urgent task of addressing the climate challenge,” highlighted Ban Ki-Moon, UN Secretary-General in his message on the occasion of the International Day for the Preservation of the Ozone Layer.

Achim Steiner, United Nations Environment Programme (UNEP) Executive Director urged for immediate action that would link both climate and ozone issues. "If we act now in understanding the connections between ozone and climate action, we can avoid a major problem. Should we not succeed in having a mutually reinforcing compatible strategy, we would actually undermine, ironically, the efforts in one international effort called the UNFCCC by the inadvertent impacts of the Montreal protocol, and that is why this issue has become so significant," he said.

HFCs currently increasing at rate of 7% each year

HFCs, developed as replacements for ODSs (ozone depleting substances), currently contribute around 10% of the maximum CFC GWP-weighted emissions (around 10 gigatonnes CO2eq/year). “However, if the HFC emissions continue to grow at 7% per year, the GWP-weighted emissions will approach the 1990 peak GWP values of ODS emissions in about 35 years,” the WMO/UNEP report reads.

By 2050, HFC banks are estimated to grow to as much as 65 gigatonnes CO2-equivalent. The climate change impact of the HFC banks could be reduced by limiting future use of high-GWP HFCs to avoid the accumulation of the bank, or by destroying the banks. This large bank is the result of high-GWP HFCs being used almost entirely in products and equipment where they are contained for many years to decades, e.g., in air conditioning and refrigeration systems.

Could TFA become another ‘unintended’ consequence?

Part of the industry push for widespread use of unsaturated HFCs with low GWP as replacements for high GWP HFCs is resulting in the production of trifluoroacetic acid (TFA), the result of the atmospheric oxidation of HFC-1234yf.

The report notes that, “while the environmental effects of TFA are considered to be negligible over the next few decades, potential longer-term impacts could require future evaluations due to the environmental persistence of TFA and uncertainty in growth in future uses of HFOs.”

Full report to be published in 2015

The Scientific Assessment of Ozone Depletion 2014, which is the first comprehensive update in four years, will be presented at the annual meeting of the parties to the Montreal Protocol, to be held in Paris in November 2014. The full body of the report will be issued in early 2015.