A long-standing concern is that efforts to protect the ozone layer by phasing out CFCs might worsen global warming by encouraging the use of alternatives such as HCFCs, HFCs and PFCs that are strong greenhouse gases.
The study, by the Intergovernmental Panel on Climate Change (IPCC) with input from an expert panel under the Montreal Protocol, was considered by delegates from 99 countries at a meeting in Ethiopia in April. The full report will be published in the summer, but the meeting approved a summary for policymakers.1The summary considers trends in emissions of ozone-depleting substances such as CFCs and HCFCs, together with emissions from HFCs and PFCs from applications where they are used as replacements. It does not address significant sources of HFCs and PFCs such as aluminium or semiconductor production.
Global average levels of ozone depletion have "now approximately stabilised", the report says, and atmospheric concentrations of CFCs are falling by 0-3% per year. However, concentrations of HCFCs and HFCs are increasing by 3-7% and 13-17% per year respectively.
Ozone-depleting substances are also potent greenhouse gases, though they are not covered by the Kyoto Protocol. Indeed, because HCFCs and HFCs generally have lower global warming potentials than the CFCs they replace, the total warming impact from halocarbons fell by a factor of three between 1990 and 2000.
Trade bodies representing HFC producers and users seized on the report’s finding that by 2015, HFCs will contribute just 1% to the total warming impact of man-made greenhouse gases. However, the report also warns that radiative forcing from HFCs could show "significant growth" beyond that date.
In absolute terms, emissions of HFCs are set to rise dramatically. Under business as usual, the report expects that total emissions of halocarbons will fall slightly by 2015 as CFCs work their way through the system. However, the contribution from HFCs will grow dramatically (see figure) - and emissions of the gases will be equivalent to roughly 5% of global CO2 emissions from fossil fuel burning.
Moreover, the "bank" of HFCs and HCFCs in equipment, foams and stockpiles is also set to increase markedly. "The build-up of banks of (relatively) new applications of HFCs will - in the absence of additional bank management measures - also significantly determine post-2015 emissions," the report warns.
By applying current best practice and recovery methods, the report says there is "potential" to reduce total emissions from halocarbons to half the "business as usual" levels in 2015.
Some 60% of the potential savings come from measures to tackle HFCs. The report suggests that in theory, the growth in HFC emissions could be cut to 20% between 2002 and 2015:
Mobile air conditioning units are the subject of a proposed EU Directive (ENDS Report 357, pp 50-51 ). The report suggests that improved containment and end-of-life recovery could reduce emissions by 50%, rising to up to 70% if systems based on CO2 or low-impact HFCs enter the market.
HFC producers argue that CO2 emissions from appliance energy use need to be considered alongside the direct global warming impact of their products. The IPCC ducks the long-running controversy over this life-cycle approach, noting that "due to limited availability of published data and comparative analyses, such comprehensive assessments are currently almost absent."
The European Fluorocarbons Technical Committee, which represents producers, welcomed the report. Vice-chairman Tim Vink said it confirms that policies focusing on containment - such as a draft EU Regulation on F-gases - are "an effective means of delivering HFC emission reductions."
However, MIPIGGs, an industry group set up to promote "not in kind" alternatives to fluorocarbons, accused the report of "pie-in-the-sky optimism". It argues that by mixing up HFCs and ozone-depleting substances which are already being phased out, the report "disguises" the fact that HFC emissions are set to increase "vastly".
MIPIGGs has written to European governments urging them to ensure that the report "does not become the basis for decision-making on HFCs in your countries, the EU or more widely."
Eric Johnson of Atlantic Consulting complains that the report "leaps to containment as the answer" and fails to compare its effectiveness with other options such as product bans or taxation. Mr Johnson claims that about one-third of the authors of the summary "are direct or indirect representatives of the F-gas industry" - and that "if given the chance, turkeys will vote against Christmas."