Atmosphere

Theme commentary
Tom Beer, Michael Borgas, Willem Bouma, Paul Fraser, Paul Holper and Simon Torok
CSIRO Atmospheric Research
prepared for the 2006 Australian State of the Environment Committee, 2006

Discussion and conclusions

On the basis of this commentary, some of the unfavourable news from Australia State of the Environment 2001 continues to be unfavourable. There is still no decline in four-hourly maximum concentrations of ozone in urban areas—especially Sydney—indicating that photochemical smog in those areas remains an issue. Even the one-hourly maximum ozone concentrations in Sydney are increasing. In contrast, improved fuel quality standards and vehicle emission controls have significantly reduced pollution from new vehicles during a period that has seen a substantial increase in vehicle kilometres travelled.

Dust and other particulate matter, including woodsmoke, continue to be of concern in some regions and localities. The concern now relates to the fine particulate matter (PM2.5), which is believed to dominate adverse health effects, rather than the coarser material (PM10). Some of these health effects may arise from pollen or seeds, but Australia still does not have a systematic pollen monitoring system established.

In 2002, Australia changed the methodology used to estimate emissions of greenhouse gases, to include land clearing, and so follow the accounting procedures recommended in the Kyoto Protocol.

The Australian average surface temperature continues to increase, such that the warming since 1950 has been almost 0.2 °C per decade. The past decade has seen Australia’s highest recorded mean annual temperatures

Although there is no evidence of a significant reduction in the Antarctic ozone hole in recent years, it stopped growing in the mid- to late 1990s.