"Our new data and understanding now point to the critical situation we face: to slow future [climate] change, we must start taking action soon. At the same time, because of our past and ongoing activities, we must start to learn to live with the likely consequences - more extreme weather, rising sea levels, changing precipitation patterns, ecological and agricultural dislocations, and the increased spread of human disease".[i]
PIGGs are a group of potent industrial greenhouse gases - which are wholly or mostly produced by industry [man-made] and are not part of natural biogeochemical cycles and processes. This distinguishes them from other important greenhouse gases such as CO2, N2O and CH4.
The Kyoto Protocol to the Framework Convention on Climate Change has listed these three PIGGs as part of the "basket" of "radiatively important greenhouse gases" separate from the main greenhouse gases, to be included in national emission reduction targets.
The three gases are:
According to the US Environmental Protection Agency:
"in addition to having high global warming potentials, SF6 and many HFCs and PFCs have extremely long atmospheric lifetimes, resulting in their essentially irreversible accumulation in the atmosphere." [ii]
These PIGGs have extremely high global warming potentials (see table) and are being emitted at a rapidly increasing rate. Projections indicate emissions could rise 150% between 1995 and 2010.
"Molecule for molecule, [HFCs] have 150-4,000 times more global warming potential than carbon dioxide. Virtually unused in 1990, HFCs are expected to account for 1-3 per cent of total emissions of greenhouse gases in 2010 in most developed countries, according to UN estimates.[iii]
| Empirical formula or composition | Name | GWP 100 |
|---|---|---|
| Perfluorocarbons (PFCs) | ||
| CF4 | 14 | 5700 |
| C2F6 | 116 | 11400 |
| C3F8 | 218 | 8600 |
| Hydrofluorocarbons (HFCs) | ||
| CHF3 | 23 | 14800 |
| CH2F2 | 32 | 880 |
| C2HF5 | 125 | 3800 |
| C2H2F4 | 134a | 1600 |
| C2H3F3 | 143a | 5400 |
| C2H4F2 | 152a | 190 |
| C3HF7 | 227 | 3800 |
| C3H2F6 | 236fa | 9400 |
| C3H3F5 | 245fa | 1040 |
| C4H5F5 | 365mfc | 910 |
| C5H2F10 | 43-10mee | 1700 |
| HFC blends | ||
| 143a/125/134a (52:44:4) | 404A | 4540 |
| 32/125/134a (23:25:52) | 407C | 1980 |
| 32/125 (50:50) | 410A | 2340 |
| 125/143a (50:50) | 507A | 4600 |
| Others | ||
| SF6 | 32 400 | |
| NF3 | 8000 | |
| C4F9OCH3 | HFE 7100 | 390 |
Globally, HFCs, the most significant of the F-gases, could represent 15% of all greenhouse gases by 2040, and 40% by 2100 as they replace ozone destroying CFCs and HCFCs.[v]
The US EPA notes that the increase in HFCs as replacements for Ozone Depleting Substance is "expected to continue for many years." [vi]
Much controversy surrounds the seemingly innocent estimates of HFC production and emissions - both past present and future. These figures are crucial to the debate and questions remain over the method of calculations used, the baseline dates and emissions from leakage.
When CFCs and HCFCs were banned under the Montreal Protocol, the presumption was that if they were manufactured, they would eventually get into the atmosphere. However, the Kyoto Protocol seeks only to reduce rather than eliminate emissions. This has opened a whole new debate about whether HFCs do leak from the equipment they're used in.
But given that there are suitable alternatives for HFCs, MIPIGGs argues that they should be eliminated and replaced. [For a detailed list of alternatives please download from our library: "Reducing Emissions of HFCs, PFCs, and SF6 in the EU", Jason Anderson, Climate Network Europe or go to www.climnet.org
"Once the infrastructure has been put in place for large scale and continuous HFC emissions, it will be much more difficult and costly to reverse the trend." [vii]
HFCs were heavily promoted when the Montreal Protocol set phase-out dates for ozone destroying CFCs and HCFCs. HFCs were seen as the way out of ozone layer destruction. However, the UN Climate Convention's Kyoto Protocol now recognises them as global warming gases which need to be phased out. In 1990, there was virtually no HFC use in the EU. But this has grown to 37,000 tonnes in 1998 and, potentially, 129,000 tonnes by 2012.[viii]
HFCs are used as refrigerants, both for chillers/refrigeration and for air conditioning, as aerosol propellants and foam blowing agents. They are manufactured by the chemical industry as alternatives. One set of stronger HFCs, HFC-23, are produced and emitted as by-products of HCFC-22 manufacture.
In virtually all applications there are environmentally benign alternatives to HFCs.
Alternatives include switching to different gases and methods, for example a pump spray instead of an aerosol. Environmentally benign compounds such as hydrocarbons (HCs), air, CO2, water, and ammonia are proven alternatives for both refrigeration and air-conditioning.
PFCs are mainly an unintended by-product of primary aluminium smelting, but also from the semiconductor industry.
The most efficient processes also create the fewest PFCs. Releases from this sector will continue to fall in the future through autonomous shifts by industry, though more should be done to ensure use of only the very best technologies.
The semiconductor industry has also committed to a 10% decrease in FC use, primarily PFCs, despite rapid expansion. New processes and substitute gases for etching and cleaning are becoming available. However, there are new smelters being built, with an as yet unknown capacity.
For tyres and shoes: Nitrogen.
The world's leading producer of magnesium, Norsk Hydro, plans to phase out SF6 by 2001 or 2002 and replace it with SO2, encouraging customers to do likewise. Some never made the switch away from SO2 to SF6.