Australia’s emissions in context

2016

Although Australia’s emissions in 2015 of 541 megatonnes of carbon dioxide equivalent2 (MtCO2-e) appear small alongside the most recent estimates from major emitters such as China (10,756 MtCO2-e; 2010 estimate; UN Climate Change Secretariat 2015) and the United States (5791 MtCO2-e; 2013 estimate), they are not insignificant, being on par with countries such as the United Kingdom (570 MtCO2-e).

In addition, Australia’s emissions are some of the most ‘intense’ in the world. Two measures of the emissions intensity of a country are comparison of emissions levels with population (per-person emissions) and comparison of emissions levels with the economy (per dollar of gross domestic product—GDP).

Per person, Australia’s CO2 emissions in 2013 were the second largest of countries in the OECD—16.8 tonnes, which is 75 per cent higher than the OECD average of 9.6 tonnes (Figure ATM4).

Box ATM2 Stratospheric ozone

The stratosphere is the layer of the atmosphere that begins at an altitude of around 10 kilometres. The stratosphere contains about 90 per cent of the ozone in the atmosphere, which helps to make Earth inhabitable by absorbing a large proportion of incoming solar ultraviolet (UV) radiation before it reaches Earth’s surface. UV radiation is harmful to a range of biological systems, including human health. It damages cells, and causes sunburn and premature skin ageing in low doses. At higher levels, it can cause skin cancer and suppress the immune system. Note that although stratospheric ozone protects human health, ozone near the ground, where it can be breathed in, is a pollutant and harmful to health. (See Ozone for further discussion of ozone as a pollutant.)

The stratospheric ozone layer was threatened by human-produced ozone depleting substances (ODSs), which were widely used in refrigerators, air-conditioners, fire extinguishers and electronic equipment; as solvents for cleaning (including dry-cleaning); and as agricultural fumigants. These substances contain chlorine and bromine atoms, which are released over time when ODSs break down and then react with ozone molecules to break them up. This has led to a reduction in stratospheric ozone in the mid-latitudes and a particularly severe reduction over Antarctica, known as the ozone hole (described in the Antarctic environment report). Since peaking in the 1990s, the atmospheric abundance of nearly all ODSs that are controlled under the Montreal Protocol has declined. However, these substances are long-lived in the atmosphere and many are also powerful greenhouse gases.

Figure ATM5 shows total column ozone levels above Melbourne, Darwin, Brisbane and Hobart for January each year from 1979 to 2015, where data are available. The dark line shows a 5-year running mean. Although considerable year-to-year variability is evident, such as the influence of the 11-year solar cycle (which peaked around 1980, 1991, 2002 and 2013), the decreasing trend seen in the 1980s and the first half of the 1990s indicates recovery of stratospheric ozone levels, as actions under the Montreal Protocol have become effective.

Australia’s relatively high level of emissions per person reflects the nation’s heavy reliance on fossil fuels as a primary energy source and, in particular, the dominant role of coal (an emissions-intensive fuel) in the production of electricity (Figure ATM6).

Australia’s CO2 emissions were also the second largest of OECD countries in 2013 per US $1000 of GDP—0.43 tonnes, which is 1.4 times the OECD average of 0.30 tonnes (Figure ATM7).

Despite these high rankings, Australia’s emissions intensity decreased between 1990 and 2015. Since 1990, emissions per person have dropped by 27 per cent, and emissions per dollar of real GDP have fallen by half (52 per cent) (Figure ATM8). Australia’s emissions intensity has been decreasing more strongly in recent years:

  • In the past 10 years, emissions per person have decreased on average by 2.6 per cent per year, compared with an average decrease of 0.3 per cent per year between 1990 and 2005.
  • In the past 10 years, emissions per dollar of real GDP have decreased on average by 3.7 per cent per year, compared with an average decrease of 2.4 per cent per year between 1990 and 2005.

Much of this decrease can be attributed to a decrease in the proportion of electricity generated from coal, as discussed in more detail under Analysis of emissions trend drivers.

Keywood MD, Emmerson KM, Hibberd MF (2016). Climate: Australia’s emissions in context. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/theme/climate/topic/2016/australias-emissions-context, DOI 10.4226/94/58b65c70bc372