Hydrofluorocarbons or 'HFCs' have been increasingly used in the last decade or so as an alternative to ozone damaging CFCs in refrigeration systems. Unfortunately, though they provide an effective alternative to CFCs, they can also be powerful greenhouse gases with long atmospheric lifetimes.

The three main HFCs are HFC-23, HFC-134a and HFC152a, with HFC-134a being the most widely used refrigerant. Since 1990, when it was almost undetectable, concentrations of HFC-134a have risen massively.

HFC-134a has an atmospheric lifetime of about 14 years and its abundance is expected to continue to rise in line with its increasing use as a refrigerant around the world.

Human Impact

The widespread use of HFCs as refrigerants will inevitably lead to increases in their atmospheric concentrations. HFCs have provided an efficient and cost effective alternative to the use of the ozone destroying CFCs, now banned under the Montreal Protocol. However, with HFC-134a and, in particular, HFC-23 having such long atmospheric lifespans (14 and 260 years respectively) HFCs do pose a significant greenhouse gas problem.

Potential for control

Alternative refrigerants to HFCs, such as hydrocarbon based coolants, are already commercially available. However, HFCs are now used in huge numbers of fridges and the like around the world. Phasing out of HFC use, and careful collection and disposal of existing HFC refrigerants, seems the best option now available in the context of limiting their greenhouse gas impact.