ATMOSPHERE

For 2006, Australia's net greenhouse gas emissions were estimated to be 576.0 megatonnes of carbon dioxide-equivalent (CO₂-e) (Endnote 1). Australia's net emissions in 2006 were 1% lower than in 2005, and 4.2% above 1990 levels (the year 1990 is the base period for the reporting of emissions under the Kyoto protocol). Emissions tended to rise gradually over the period from 1995. The sharpest rise was between 1997 and 1998 when emissions from land use change rose rather than fell, with another steep rise between 2004 and 2005. The energy sector is the largest source of greenhouse gas emissions. Emissions from this sector rose steadily from 1990 to 2006 (Endnote 2).

ABOUT THE INDICATOR

MAP reports on two dimensions of the air and atmosphere: urban air quality and greenhouse gas emissions.

Climate change is widely perceived as one of the most significant international environmental concerns. The main gases in the atmosphere, nitrogen and oxygen, are almost completely transparent to the sun's rays. But water vapour, carbon dioxide and other gases form a blanket around the Earth, trapping heat - a process called the greenhouse effect. Human activity is increasing atmospheric concentrations of existing greenhouse gases (such as carbon dioxide and methane) and adding new gases such as chlorofluorocarbons (CFCs).

Net emissions of greenhouse gases are estimated using information about total emissions, less any credits from forest sinks. These credits are estimates of how much carbon dioxide has been absorbed by new and expanding forests established in Australia since 1990.

SEE ALSO

State and territory spreadsheets
The air and atmosphere: atmosphere - Measures of Australia's Progress, 2006
Topics @ a Glance - Environment & Energy
Carbon Pollution Reduction Scheme, White Paper, 2008
State of the Environment reporting

ENDNOTES

1. The indicator measures million tonnes (megatonnes) of carbon dioxide (CO₂) equivalent emissions. Different greenhouse gases have different effects and remain in the atmosphere for different periods of time. A tonne of methane, for example, contributes as much to global warming as 21 tonnes of CO₂. To assess the impact of the different gases together, emissions of each gas are converted to a common CO₂ equivalent scale and added. For example, one tonne of methane plus one tonne of CO₂ would equate to 22 tonnes of greenhouse gases CO₂ equivalent.

Estimates for forest conversion, a component of overall greenhouse gas emissions, should be considered as interim only for 2004 and 2005, and will be revised when areas of forest conversion are confirmed in the next update of the National Greenhouse Gas Inventory 2007. In particular, the forest conversion component was not re-estimated for 2006 and, as an interim measure only, was assumed to be unchanged from the 2005 estimate. For further information, see the National Inventory Report 2006 Vol 2 Part A on the Department of Climate Change website.

The data are based on estimates produced using Kyoto accounting methods.

2. Australian Government Department of Climate Change 2008, National Greenhouse Gas Inventory 2006, Australian Greenhouse Office, Canberra, viewed 1 August 2008.

Australian Government Department of Climate Change 2008, National Inventory Report 2006 Vol 2 Part A, Australian Greenhouse Office, Canberra, viewed 22 July 2007.

LINK TO THE DETAILED SUMMARY