Climate change

3 What are the pressures?

The key pressure in climate change is the emission of greenhouse gases. Pressure indicators therefore include sources of greenhouse gases, greenhouse gases per head of population and greenhouse gases per unit of economic output.

3.1 Sources of global and Australian greenhouse gas emissions

Global emissions of greenhouse gases have risen steeply since the start of the industrial revolution, with the largest increases coming after 1945. A relatively small number of countries produce the majority of greenhouse gas emissions: the 25 largest emitters produce approximately 83% of global emissions (Table 3). Emissions of greenhouse gases from human sources come primarily from the burning of fossil fuels (coal, oil and gas) to create energy for electricity production, heat generation and transportation. Energy-related emissions accounted for approximately 60% of global emissions in 2000 (Baumert et al. 2005). Deforestation is estimated to account for 15% of global emissions (van der Werf et al. 2009), and agriculture contributes a similar proportion.

Significantly, Australia is one of the top (highest) 25 greenhouse gas emitting nations, ranked 15th in the world based on total emissions in 2005 and contributing 1.5% to total emissions (Figure 5; Table 3). Australia’s emissions per capita are the 7th highest in the world, higher than any of the top 25 emitting nations and the highest in the Organisation for Economic Co-operation and Development (OECD) (Garnaut 2008). Compared with other OECD nations, Australia’s reliance on coal for generating electricity is a key cause of our high per-capita emissions (Garnaut 2008).

3.2 Sources of South Australian greenhouse gas emissions

South Australia contributed 5% of Australian emissions in 2010, at 30.4 million tonnes (Mt) of CO₂ equivalents (including net emissions from the land use, land-use change and forestry [LULUCF] sector—afforestation, reforestation and deforestation activities). CO₂ equivalent (CO₂-e) is a measure of how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of CO₂ as the reference. If the reduction in LULUCF emissions over this period is included (the sector was a 1.5 Mt source in 1990 but a 1.4 Mt sink in 2010, as a result of reduced deforestation and increased forestry plantings), overall net emissions fell by 6%, from 32.2 Mt to 30.4 Mt. Excluding LULUCF, total South Australian emissions increased by 4% between 1990 and 2010 (Table 4).

The energy sector is the dominant source of state emissions, contributing 73% of the total inventory in 2010 (Figure 6). Emissions from the energy sector include emissions from the generation of electricity, the direct combustion of fuels onsite (such as gas and diesel to produce stationary energy), the combustion of fuel for transport and interconnector emissions. Total energy sector emissions (excluding the land-use sector) rose 10% between 1990 and 2010 (Table 3.5). Electricity generation contributed to a 2.6 Mt increase in emissions between 1990 and 2010, with emissions peaking in 2000. The impact of the recent increase in renewable energy generation is evident, with emissions declining slightly in the past few years. However, the underlying electricity consumption in the commercial, industrial and residential sectors has continued to grow.

South Australia has two coal-fired generators: Northern Power Station and Playford B Power Station, both located at Port Augusta. These consume approximately 3.8 Mt of coal annually from the Leigh Creek coal mine (AEMO 2011a). In 2011–12, fossil fuels provided just under 75% of electricity generation, with gas contributing 50% and coal 24% (AEMO 2012).

Transport was the source of 19% of the state’s total emissions in 2010. Transport emissions grew by 0.5 Mt (8%) from 1990 to 2010, caused by increasing road freight emissions, while passenger road emissions remained steady over this period (DCCEE 2012b).

Sources: Australian Government Department of Climate Change and Energy Efficiency, and South Australian Department of Environment, Water and Natural Resources modelling

Figure 6 South Australia’s greenhouse gas emissions by sector (excluding land use, land-use change and forestry), 2010

Analysis of emissions on an economic sector basis highlights the growth in residential emissions beyond what would be expected as a result of the increase in population. Residential emissions took up a larger share of the state’s emissions in 2010 than in 1990. The South Australian population grew by 15% over this period, while emissions from residential electricity increased 33% (Table 6).

3.3 South Australian greenhouse gas emissions per capita

On a per-capita basis, South Australian emissions trended upwards to peak in 2000, but then declined back to 1990 levels by 2007–08. They have fallen below 1990 levels in the past three years, primarily under the influence of increases in the generation of renewable energy in the state (Table 7). This can be contrasted with the Australian trend in the past few years, where, after following a similar upward trend, emissions per capita were at 1990 levels in 2010. South Australian per-capita emissions were substantially (8–22%) lower than the national figures throughout the period 1990–2010.

3.4 South Australian greenhouse gas emissions per gross state product

There has been a 42% reduction in the greenhouse gas intensity of the South Australian economy—that is, the tonnes of CO₂-e produced per million dollars of gross state product—since 1990 (Table 3.8). The similar reduction in the greenhouse gas intensity of the Australian economy has been attributed to a strong growth in the lower emissions service industries and improved energy efficiency (ABS 2010). In addition, Australian manufacturing has been in decline, in parallel with the growth in manufacturing productivity of developing economies (Commonwealth of Australia 2008).

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