UN report projects that increasing use of HFCs likely to have a significant climate impact by 2050; equivalent to current total annual emissions from transport
A new report from the UN Environment Programme (UNEP) projects that by 2050, hydrofluorocarbons (HFCs) could be responsible for emissions equivalent to 3.5 to 8.8 Gigatonnes (Gt) of carbon dioxide (Gt CO2eq)—comparable to total current annual emissions from transport, estimated at around 6-7 Gt annually. Used in products such as air conditioners, refrigerators, firefighting equipment and insulation foams, HFCs are becoming popular as replacements for those phased-out or being phased-out to protect the ozone layer.
The contribution of HFCs to climate forcing is currently less than 1% of all greenhouse gases. However, levels of HFCs are rising as they replace HCFCs—HFC 134a, the most popular type, has increased in the atmosphere by about 10% per year since 2006. The UNEP report notes the projected HFC emissions would be equivalent to 7 to 19% of the CO2 emissions in 2050 based on the IPCC’s Special Report on Emissions Scenarios (SRES), and equivalent to 18 to 45% of CO2 emissions based on the IPCC’s 450 ppm CO2 emissions pathway scenario. (There is inherent uncertainty in such projections, the report authors caution.)
If HFC emissions continue to increase, they are likely to have a noticeable influence on the climate system. By 2050, the buildup of HFCs is projected to increase radiative forcing by up to 0.4 W m-2 relative to 2000. This increase may be as much as one-fifth to one-quarter of the expected increase in radiative forcing due to the buildup of CO2 since 2000, according to the SRES emission scenarios. However, the future radiative forcing by HFCs in 2050 would be relatively small, at the same level as it is today (<1% of CO2), if the current mix of HFCs were replaced with low-GWP substances with lifetimes of a few months or less.—HFCs: A Critical Link in Protecting Climate and the Ozone Layer
HFCs are, along with CO2, methane and other gases, controlled under the UN’s Framework Convention for Combating Climate Change and its Kyoto Protocol. Measures to protect the ozone layer are carried out under the Montreal Protocol on Substances that Deplete the Ozone Layer. The new report—HFCs: A Critical Link in Protecting Climate and the Ozone Layer—was launched in Bali, Indonesia, at the 23rd Meeting of the Parties to the Montreal Protocol.
The more than 20 year-old international effort to save the ozone layer ranks among the most successful examples of cooperation and collaboration among nations—the original chemicals, known as CFCs, were phased-out globally in 2010 and countries are freezing and then phasing-out the replacements, HCFCs.
However a new challenge is rapidly emerging as countries move ahead on HCFCs and that is HFCs. While these “replacements for the replacement” chemicals cause near zero damage to the ozone layer, they are powerful greenhouse gases in their own right. The good news is that alternatives exist alongside technological solutions according to this international study and while assessing the absolute benefits from switching needs further scientific refinement there is enough compelling evidence to begin moving away from the most powerful HFCs today. Cooperative action between these treaties may be the key to fast action on HFCs, assisting to maintain momentum on recovering the ozone layer while simultaneously reducing risks of accelerated climate change—Achim Steiner, UN Under-Secretary General and UNEP Executive Director
The report points to a range of alternatives that could ensure that the impact of HFCs remains small and equal to today‘s impacts:
Alternative Methods and Processes. These range from improved building design that reduces or avoids the need for air conditioners to fibre rather than foam insulation materials.
Non-HFC substances. There are already commercially available alternatives that range from ammonia to dimethyl ether for use in foams, refrigeration and fire protection systems.
Climate-friendly HFCs. Some HFCs have shorter life-times in the atmosphere of months rather than years. Some of these are being introduced such as HFC 1234ze in foams and HFC-1234yf for mobile air-conditioners.
The report notes that a significant fraction of new equipment in some sectors already uses low-GWP (global warming potential) alternatives (e.g., 36% of new domestic refrigerators and approximately 25% of new industrial air conditioners). However, low-GWP alternatives only make up a small fraction of other sectors at present, although they have the potential to substantially increase their market share.
Other findings and suggestions from the report include:
While there is some concern that replacing HFCs may lead to lower energy efficiency, recent studies have shown that a number of systems using low-GWP substances have equal or better energy efficiency than systems using high- GWP HFCs.
Barriers to alternatives to high-GWP HFCs include: the need for further technical developments, risks due to flammability and toxicity, regulations and standards that inhibit the use of alternatives, insufficient supply of components, investment costs, and lack of relevant skills among technicians.
The current use of alternatives to high-GWP HFCs demonstrates that these barriers can be overcome by activities such as, research and technological improvements, revised technical standards, training and technical assistance, as well as infrastructure developments.
Known measures that can be implemented to reduce emissions of HFCs. For example, the design of equipment can be modified to reduce leakage and the quantity of HFC used, and technical procedures can be modified to reduce emissions during manufacture, use, servicing and disposal of equipment.
There is no ‘one-size-fits-all’ solution. The solution that works best will depend on many factors such as the local situation for production and use, the costs of different alternatives, the availability of components, and the feasibility of implementation.
The report is the first of three being launched this week by UNEP in the run-up to the UN climate convention meeting in Durban, South Africa.