CFC replacements are greenhouse gases

The Montreal Protocol – which came into force in 1989 – banned or phased out CFCs and HCFCs because they damaged the ozone layer. However a new UN report has revealed that their replacements are themselves greenhouse gases and – although not at damaging levels yet – could be a cause for concern in the future

Estimates suggests that the Montreal Protocol has saved – and perhaps even bought back – many-years-worth of greenhouse gas emissions, equating to about 8Gt. Emerging evidence suggests that because of this, the stratospheric ozone layer is expected to recover to its 1980s state by the mid-21^st century.

However, Hydroflurocarbons (HFCs) – which were deemed to be like-for-like replacements for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HFCs) – represent a new threat to the future of the planet. It is now known that as greenhouse gases they are many more times potent than CO₂.

“HFCs are excellent substitutes for use in products such as refrigerators and industrial air conditioners, but they are extremely powerful global warming gases,” said the report, HFCs: A Critical Link in Protecting Climate and the Ozone Layer.

Although their current contribution to climate forcing is less than 1%, the use of HFCs is growing at approximately 8% per year. The report predicts that by 2050 – without action – levels could rise so high that they cancel out climate benefits already won by the phase out of CFCs and other ozone depleting substances.

Different HFCs vary significantly in their ability to influence the climate due to their differing atmospheric lifetimes and accumulation ratio in the atmosphere.

“HFCs with lifetimes greater than a few years accumulate more in the atmosphere (for the same annual emission) and have larger climate consequences, while those with shorter lifetimes do not accumulate as much, and have less influence on the climate,” said the report.

Consumption of HFCs is projected to exceed peak consumptions of CFCs in the 1980s by 2050 because of the growing demand in emerging economics and a growing global population.

The report recognises that there is no ‘one-size-fits-all’ approach to reducing HFCs, but does suggests several alternatives to using HFCs, including designing buildings to avoid the need for air conditioning and alternative substances, and examining the life-cycle impacts of alternative options to ensure that they provide climate benefits and do not have unacceptable side effects on society or the environment.

A solution must surely involve changes like this, rather than alternative substances. If alternative substances are a must, we must look at the long-term consequences of releasing them into the atmosphere – let’s not make the same mistake twice.