The atmosphere is an essential component of all ecological systems on Earth. The atmosphere plays a critical role in regulating global, regional and local climate and is essential in supporting life on Earth. Oxygen is required for life, stratospheric ozone protects us from harmful solar radiation, and greenhouse gases help to maintain a temperature range suitable for life.

Greenhouse gases (primarily carbon dioxide and methane) occur naturally in the atmosphere, trapping the sun's warmth to enable the Earth's surface temperature to support life. Human activities, particularly the burning of fossil fuels (e.g. coal, oil and gas), have increased the atmospheric concentrations of these gases, which means they trap more heat, thereby contributing to global warming and climate change. (Endnote 1)

In the decade to 2009, Australia's greenhouse gas emissions increased by 13%, rising from 483.2 million tonnes of carbon dioxide equivalent gases in 1999 to 545.8 million tonnes in 2009. Although emissions increased for most of the decade, there was a decrease in 2009 from a peak of 550.8 million tonnes in 2008.

The decline in overall greenhouse gas emissions between 2008 and 2009 was contributed to by declines in emissions from several areas. Relating to a broader economic slowdown at the time, there were declines in emissions from both fuel combustion within manufacturing industries and construction, and from metal production. In the agriculture sector, there were reductions in emission from both controlled burning, which can be quite variable, and from livestock. (Endnote 2)

For a more in-depth discussion about how the atmosphere relates to progress and whether it is improving in Australia, please see the Atmosphere chapter in Measures of Australia’s Progress, 2010 (cat. no. 1370.0).

ENDNOTE

1. CSIRO 2009, The Science of Tackling Climate Change, CSIRO, Melbourne, <www.csiro.au>, last viewed August 2011.
2. Department of Climate Change and Energy Efficiency, 2011, National Greenhouse Gas Inventory, <www.climatechange.gov.au>.