The ozone layer forms part of the Earth’s atmosphere. It is essential to the survival of humans and other animals because it filters out harmful ultraviolet radiation from the sun. Certain gases including CFCs and HCFCs damage the ozone layer, and higher levels of ultraviolet radiation caused by their use have been linked to increases in skin cancers and cataracts.
Some of our network cooling systems use CFCs and HCFCs, as do some of the air conditioning systems in our offices and shops. Although ozone-depleting gases are held in sealed systems, leaks can happen.
As part of our energy strategy, we are replacing end-of-life cooling systems in our base stations with free cooling (fresh air) systems where possible. These are also the default choice for new base stations. We expect a reduction in our use of CFCs and HCFCs as a by-product of this strategy. We are working to phase out CFCs and HCFCs in accordance with the Montreal protocol, an international agreement on the phasing out of ozone-depleting substances.
In 2007/08, we estimate that the ozone-depleting potential of the CFCs and HCFCs released by our operations was 503kg, compared with 494kg the previous year. We no longer use halon in any fire protection equipment.