Overview of state and trends of the atmosphere



What has changed since 2011?

  • Australia’s greenhouse gas emissions per person decreased from 24.1 tonnes in 2011 (DCCEE 2012) to 22.2 tonnes in 2015 (DoE 2016a), although they remain the largest of any country in the Organisation for Economic Co-operation and Development.
  • The energy sector continues to dominate greenhouse gas emissions, increasing from 74 per cent of net emissions in SoE 2011 to 76 per cent in 2015.
  • The world experienced the hottest year on record (2015) and Australia experienced its hottest year (2013).

State and trends

The changes to Australia’s climate arising from global climate change include increased average surface air temperature, increased incidence of heatwaves, decreased average rainfall in parts of the country, an increase in drought frequency and severity, sea level rise, more extreme daily rainfall events, and flooding from intense storm activity.

The oceans absorb heat from the atmosphere, which makes them warmer. The oceans also absorb CO2 from the atmosphere, which changes their chemistry in a process called ocean acidification. In the polar regions, the amount of dissolved carbonates in the waters and the pH (a measure of acidity) are changing twice as fast as in the warmer tropical and subtropical regions.

Air quality

What has changed since 2011?

  • Maximum ozone levels and levels of particulate matter less than 10 microns (PM10) in size now rarely exceed limits designed to protect human health.
  • However, evidence has emerged that human health impacts from air pollutants occur at far lower concentrations than previously thought.
  • Regulatory controls on vehicle emissions have reduced nitrogen dioxide levels.

State and trends

Air quality is generally good to very good in Australian urban areas. Since SoE 2011, maximum ozone levels have remained steady, with overall fewer exceedances of the National Environment Protection Measure designed for the protection of human health. Levels of PM10 now rarely exceed the 24-hour standard, and, when they do, it is mainly because of natural events such as dust storms or bushfires.

However, evidence about the adverse impact of air pollution on human health has increased since SoE 2011, and health effects have been observed at lower pollutant concentrations than those on which the guidelines are based. Particulate matter is a concern. In all capital cities except Adelaide and Perth, the standard for particulate matter less than 2.5 microns in size has been met in only 2 or fewer of the past 7 years.

Jackson WJ, Argent RM, Bax NJ, Bui E, Clark GF, Coleman S, Cresswell ID, Emmerson KM, Evans K, Hibberd MF, Johnston EL, Keywood MD, Klekociuk A, Mackay R, Metcalfe D, Murphy H, Rankin A, Smith DC, Wienecke B (2016). Overview: Overview of state and trends of the atmosphere. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/theme/overview/atmosphere/topic/overview-state-and-trends-atmosphere, DOI 10.4226/94/58b65510c633b