SOME of the longest-lived of all the greenhouse gases have so far been left out of the Climate Change Convention negotiations, warns Elizabeth Cook of the World Resources Institute in Washington DC.
A group of industrial products known as fully fluorinated compounds (FFCs) are currently responsible for less than 1 per cent of the warming from greenhouse gases. But their concentration in the atmosphere is increasing fast. Most worrying, FFCs 鈥渉ave atmospheric lifetimes of up to 50 000 years鈥�, compared to about a century for carbon dioxide and about 15 years for methane.
FFCs are used as solvents in the manufacture of semiconductors, aluminium smelters and magnesium foundries. Some are substitutes for ozone-eating CFCs. One, sulphur hexafluoride, is, molecule for molecule, 鈥渢he most potent greenhouse gas IPCC scientists have ever evaluated鈥�, says Cook. Its concentration in the atmosphere is increasing at around 8 per cent per year.
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鈥淚ndustry鈥檚 efforts to find new uses for FFCs 鈥� even for the important goal of replacing ozone 鈥� depleting substances 鈥� seem imprudent,鈥� she says.
