Two new synthetic greenhouse gases are getting their “debut” at the Greenhouse 2009 atmospheric science conference in Perth this afternoon and they add extra and undeniable contributions to the problems of anthropogenic global warming.
Small but worrying accumulations of nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2) have been discovered in a joint study by the Scripps Institution of Oceanograpahy in the US and CSIRO scientist Dr Paul Fraser from the Centre for Australian Weather and Climate Research.
“Both are very long lived and are becoming widely distributed through the atmosphere,” Fraser said this morning.
Ironically, they also owe part of their use in industry to their replacement of other harmful greenhouse and ozone depleting gases.
Neither gas threatens the ozone layer but both diminish the capacity of the atmosphere to reradiate energy, thus adding to the greenhouse effect.
These are man made gases that have not played any known part in the pre-industrial climate of the planet.
Nitrogen trifluoride is used in the electronics industry in the making of liquid crystal flat-panel video screens as a replacement for the perfluorocarbons or PFCs phased out after they were implicated in high atmosphere chemical reactions that were enlarging the Antarctic ozone hole and causing similar holes to appear over Arctic regions.
Sulfuryl fluoride has become a large scale industrial fumigant replacing methyl bromide, which was a major contributor to ozone layer destruction.
Fraser says the good news about sulfuryl fluoride is that it can be captured at some additional cost when it is used in cleaning shipping containers or big structures, which are its prime applications.
However nitrogen trifluoride is another matter. “It appears to remain in the atmosphere forever once it is released, and it is difficult to trap.
“I don’t think international agreements and the about to be revised Kyoto Protocol will tolerate this situation. Something that is small at present, but essentially permanent and has such a significant potential to add to global warming has to be cut off,” Fraser says.
He says he expects the electronics industry will throw resources at finding a nitrogen trifluoride replacement, while capture techniques for sulphuryl fluoride will be refined and expanded, bearing in mind that it represents a lower threat to the environment than the methyl bromide it replaced.
“I believe both these gases will be incorporated in emissions reduction targets in the near future,” Fraser says.