Pollution growing at a record rate

Herald Sun, 15may06

ATMOSPHERIC levels of carbon dioxide and some other greenhouse gases grew at record rates last year, a CSIRO scientist said today.

But some of the worst ozone-depleting gases in the atmosphere had showed a drop in the past eight years, Paul Fraser, from CSIRO Marine and Atmospheric Research, said. The results of the testing at the Cape Grim meteorological station in Tasmania will feature at a climate meeting in Sydney tomorrow.

Dr Fraser said carbon dioxide grew by two parts per million (0.54 per cent) in 2005, the fourth year in a row of above-average growth. "To have four years in a row of above-average carbon dioxide growth is unprecedented," Dr Fraser said.
"In addition, the trend over recent years suggests the growth rate is accelerating."

He said the 30-year record of air collected at the Cape Grim observation station showed growth rates of just over one part per million in the early 1980s but, in recent years, carbon dioxide had increased at almost twice this rate. "This is a clear signal that fossil fuels are having an impact on greenhouse gas concentrations in a way we haven't seen in the past," Dr Fraser said.

Synthetic greenhouse gases, including hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6), displayed a strong increasing trend.

Dr Fraser said the highest growth rate, a seven parts a 1000 billion or 5.3 per cent increase, was recorded in 2005. Nitrous oxide also showed an increasing growth rate, growing by about one part per billion, or 0.3 per cent, in 2005.
Dr Fraser said there was some good news for the atmosphere. "Concentrations of methane, the second most important gas responsible for the enhanced greenhouse effect, have not grown for six years," he said. "In fact, the past two years have shown slight decreases in methane, the first time we have seen this."

While the reason for decrease was not certain, Dr Fraser suggested it might be due to better management of the exploration and use of natural gas, leading to less leakage. There also was good news for the ozone hole. "Ozone depleting gases have been decreasing since 1997," Dr Fraser says. "The fall in concentrations has continued in 2005, so we have seen a decline in concentration of ozone-depleting gases for nine years now." – AAP