Indicator: Greenhouse Contributions
On a per capita basis, the ACT continues to be a high greenhouse gas-emitting region. Reasons for this include our climate, our urban design and our lifestyle. Electricity consumption is far and away the ACT’s greatest single source of greenhouse gas emissions. This is followed by transport.
The ACT Government has set itself the target of reducing Greenhouse gas emissions to their 1990 level by 2008, followed by a further 20% reduction by 2018.
The ACT Greenhouse Strategy: 2002 Review of performance and options for the future indicates that this will be hard to achieve using existing measures. The situation is made more difficult because of the existence of Commonwealth Government land and activities within the ACT, over which the ACT Government has no control.
Even so, the ACT Government retains its stated target. The task is somewhat more difficult than originally anticipated because the 1990 emissions level is now believed to be lower than first estimated.
The January 2003 bushfires in the ACT may have injected as much as 18-months’ worth of ‘normally’ produced greenhouse gas emissions into the atmosphere. The next review of the Greenhouse Strategy will need to take into account emissions from the bushfires, particularly if changes in landuse mean the burnt vegetation is not replaced.
The ACT is currently responsible for about 4.2 million tonnes of greenhouse gas emissions per year (ACT Greenhouse Strategy). This is less than 1% of Australia’s total greenhouse emissions but on a per capita basis the ACT continues to be a high-emitting population.
If current trends continue – the so-called ‘business as usual’ scenario – emissions in 2008 are projected to be 29% higher than those in 1990 (4605 kilotonnes of carbon dioxide equivalents). Thus, the 2008 target can be achieved only if expected emissions are reduced by 29%, or 1047 kilotonnes of carbon dioxide equivalents (see Table 1).
The Territory is ‘responsible’ for these emissions in a broad sense – not all the emissions literally take place within the Territory’s boundaries. For example, the ACT relies on power generators elsewhere for virtually all its electricity. Greenhouse gas emissions caused by generating power used within the ACT are attributed to the ACT.
|Table 1: Business as usual emission projections (kilotonnes of carbon dioxide equivalents)|
|Year||1990||1997||1999||2000||2008||Increase 1990–2008||Increase 1997–2008|
* Projections of transport related emissions were performed on a calendar year basis whereas all other projections have been performed on a financial year basis. The discrepancy between these two data sets is considered to be minor, especially in relation to the greater uncertainties of predicting future circumstances.
** Figures have been rounded, so some totals do not add up.
Source: Australian Greenhouse Strategy: Review and assessment of options.
Figure 2: Per capita electricity consumption index, ACT
Electricity use is the ACT’s greatest single source of greenhouse gas emissions. This is followed by transport (see Figure 1 in the downloadable pdf).
Energy supplied to commercial and residential sectors accounts for about 63% of all emissions, transport accounts for 24%, and waste 8%.
The bulk of electricity sold in the ACT is derived from black coal generation stations. Unfortunately, information on quantities of electricity purchased and from which sources it was purchased is now commercially confidential. However, ActewAGL figures show that 44.4 GWh of green energy was sold in 2001–02. As of 30 June 2003, there were3.2% of customers participating in the GreenChoice program. Support for GreenChoice has increased from 2% of households since the previous reporting period.
Figure 1: ACT sources of Greenhouse gas emissions, as at 2000
The amount of energy consumed per household appears to be rising (see Figure 2).
The figures use 1994 as a baseline year. It is clear that after a period of relative stability, per capita consumption has been rising from 1997, perhaps as a result of greater use of computers, modems and appliance chargers at home, or because of a trend towards more airconditioning. The ACT’s ageing population could mean a greater percentage of people wanting constant air cooling or heating. As well, there has been strong marketing of domestic air-conditioners and of the purported benefits of ‘reverse cycle’ devices.
On average, the number of days in a year when Canberra’s weather requires air-conditioning is very few. Improved house design (eaves, roof insulation) and siting, along with appropriate landscaping, can enable houses to keep cool without energy-demanding air-conditioning.
The trend towards smaller households in the ACT may also be a factor affecting household energy consumption. Economies of scale would suggest a larger dwelling, housing more people, would be more efficient than several smaller ones, although apartment buildings may be an exception.
Energy consumption by ActewAGL customers accounted for about 164 thousand tonnes of carbon doixide equivalents emitted at 30 June 2003 (ActewAGL Sustainability Report).
Transport is the second most important contributor to the ACT’s greenhouse emissions. In the year ended October 2002, each ACT motor vehicle travelled on average 15,100 kilometres. This is slightly above the national vehicle average of 15,000 kilometres per year. The ACT vehicle fleet is mainly passenger cars, and the ACT has the highest proportion of all jurisdictions for the total distance travelled by passenger vehicles (84.8%) (ABS). In 2002, total annual kilometres travelled by registered motor vehicles in the ACT was estimated to be 3108 million.
This is an increase on the figure for 2001 (3048 million) but a noticeable decrease on the value for the year 2000 (3228 million). As the fuel excise levy is not imposed by the ACT Government, there are no longer any officially collected statistics on consumption of transport fuels in the ACT as separate from either New South Wales or national figures.
It is likely that the quantity of fuel used per 100 kilometres travelled has decreased slightly as vehicles have become more efficient. This is worth remembering when considering greenhouse emissions. It is also important to acknowledge that most developments affecting vehicle design, fuel and emissions are under the control of the Federal Government.
The pattern of greenhouse gas emissions in the ACT has changed relatively little over the last decade, although the quantity has increased. Both by volume and by global warming potential, the gas in greatest quantity is overwhelmingly carbon dioxide itself. Methane is a distant second place.
In November 1997, the ACT Government set a target to reduce the Territory’s greenhouse gas emissions to their 1990 level by 2008. This is to be followed by a further 20% reduction by 2018. The ACT was the first government in Australia to make such a firm commitment to greenhouse gas emission reduction.
Some implications of the Review of the ACT Greenhouse Strategy Discussion Paper August 2003 are discussed below.
Since the 1997 commitment the estimate of Greenhouse gas emissions for 1990 has changed. This is because of ‘new rules’ adopted internationally, new information, and improvements in understanding. As a result, it is now believed that emissions of greenhouse gases in 1990 were smaller than was first thought (3557 kilotonnes of CO2-e rather than 3900 kilotonnes). The ACT will have to cut its emissions by more than was first thought.
The ACT’s Greenhouse Strategy is the Government’s main response to the 1997 commitment to reduce greenhouse emissions to 1994 levels. Whether the Strategy’s suggestions will reduce emissions sufficiently to comply with the commitment is questionable. Some have not yet reached their full potential. Others, such as Federal Government actions, are beyond the effective control of the ACT Government.
ActewAGL has completed a detailed capital-cost study and technical review of an ACT gas-fired electricity generator. Commercial feasibility is under further review and a preliminary assessment of environmental and social factors arising from the site at Hume has been submitted to and approved by the ACT Government.
The main current success is in the capture of methane from waste disposal. After capture, the gas is used to generate electricity, so giving a double saving. Electricity generation from gas captured from the Mugga Lane and Belconnen landfills started in 2000 and continues, regardless of any periodic public closures of the landfill stations. In 2002–03 Mugga Lane generated 12.5GWh and Belconnen generated 7.3GWh of electricity.
In terms of greenhouse emissions saved, this methane capture and use is the largest single working response. The energy efficiency improvements in Federal and ACT Government buildings could also be significant.
ACTION currently operates two condensed natural gas-powered buses, and a small number of alternative fuel and hybrid vehicles have been leased for the ACT Government fleet. A small hydro-electric power station at Mt Stromlo, on the Bendora gravity water supply main to Canberra, produces around 3GWh each year.
The consulting group, Energy Strategies, has reviewed the ACT Greenhouse Strategy. The review concluded that the total estimated abatement likely in 2008 (using those current measures which were able to be assessed) is about 665 kilotonnes of carbon dioxide equivalents. This is about 64% of the approximately 1047 kilotonnes of carbon dioxide equivalents of abatement required. A further 382 kilotonnes of carbon dioxide equivalents, or 36%, of extra abatement in 2008 will be needed for the ACT to achieve its target.
The report concluded that:
‘significant new measures, additional to those contained in the current ACT Greenhouse Strategy, will be required if the ACT is to reach the emission reduction target which the government has set’.
The ACT Greenhouse Strategy: 2002 Review of performance and options for the future (Energy Strategies 2003), released in May 2003, found that a relatively small number of measures account for a large proportion of the total estimated abatement, and also that the ACT Government should focus on abatement measures that are within its control, such as implementation of the No Waste by 2010 Strategy, the landfill gas capture projects at Mugga and Belconnen landfills. The review found that the ACT should be able to reach its emissions target by fully implementing the measures that have been quantified.
A number of residential energy- and transport-related measures, most of which are fully under the control of the ACT Government, are expected to deliver between 1% and 3% each.
Unfortunately, many measures that have been implemented are expected to deliver very little abatement. In addition, many measures have not been implemented, some because they can be expected to make negligible contributions, but others because it appears staff resources within Environment ACT may have been insufficient to implement such a large number of individual measures.
The other significant ongoing ACT-controlled response is the No Waste by 2010 Strategy. If it succeeds, this strategy is predicted to lead to further major reduction in emissions that will be even greater than methane re-capture. However, for this to happen, the proportion of organic material in waste would need to fall from its present 55% to 10% in just five years, and the total waste volume would also have to fall considerably. This seems to be a rapid change in a short time. Moreover, this will only be an effective greenhouse measure if organic material is collected rather than put into domestic composts.
The proposal to use such collected biomass to create fuel (biomass briquettes) is admirable, but how practical, cost-effective and emission-effective both the collection and the manufacture/distribution of briquettes will be is unclear at this stage. Certainly, a separate organic waste collection service – or a reliance on households to dispose of organic waste at collection points – will force increased motor vehicle use and hence transport emissions.
There is also the question of how high compliance would be. Many households might prefer to put such waste into their own composts.
Full implementation of the No Waste by 2010 Strategyis expected to deliver a further 21% of all abatement from existing measures (13% of the overall target) and it is estimated that the landfill gas capture projects, if they continue at their current levels, will deliver 11% (7% of the overall target).
It is certainly important – and perhaps easier – for governments to change their own energy consumption patterns within government buildings than to induce change in households. Of course, improvements take money; but they also save money in the long run. Both the ACT and Commonwealth governments could contribute significantly to reducing energy consumption in ACT buildings.
One way to help might be for the ACT Treasury to establish a structured internally managed fund that departments and agencies could draw on to finance capital works, which would allow repayment from savings that would come in subsequent years as a result of energy efficiency gains.
The extensive bushfires of January 2003 burned large areas of the ACT and must therefore have emitted considerable volumes of greenhouse gases. It is possible to calculate approximate emissions using:
- the area burnt
- the fuel load (which varies with vegetation type and time since the last fire in the area)
- the carbon dioxide and other (non-carbon dioxide) greenhouse gases emission factors for the material burnt
- the extent of oxidation during combustion.
According to The Canberra Times (13 August 2003), 110,000 hectares of nature reserves and national parks were burnt; 27,000 hectares of farmland; and 11,000 hectares of plantation forest. Total fuel loads are unknown. However, NPI (1999) gives default fuel loadings for forest wildfires in the ACT of 26.1 tonnes per hectare.
Ignoring emissions from the farmland (which was not forested) and applying this loading only to the plantation forests, nature reserve and national park areas, gives a total of 3184.2 kilotonnes of fuel (122,000 hectares × 26.1 tonnes per hectare). The mass of carbon dioxide emitted is usually estimated, in greenhouse accounting, to be double the dry mass of the material burnt (the extra mass coming from atmospheric oxygen). As the burnt farmland obviously contributed some carbon dioxide as well, this would mean that more than 6,368.4 kilotonnes of carbon dioxide was emitted during the January 2003 bushfires.
Total annual man-made greenhouse gas emissions attributed to the ACT (including those emitted interstate for power consumed here) are about 4000 million tonnes of carbon dioxide equivalents. Thus the fires, in a matter of weeks, probably released more carbon dioxide than 18 months of normal activity. This ignores the greenhouse potential of other gases that would have been released (methane, nitrous oxide, NOx, carbon monoxide, etc).
However, bushfires are usually followed by vigorous re-growth, and the carbon uptake from this, over time, is usually considered to equal the carbon emitted by the fire, provided the original landuse is not changed after the fire.
Hence, in theory, net greenhouse gas release due to the bushfires could be zero. But if nonwilderness burnt areas are not replanted, net greenhouse emissions will be positive unless planting elsewhere acts as an offset. For the purpose of greenhouse auditing, emissions from bushfires are not usually included, as fires release carbon that is in the ‘current circulation’ of the carbon cycle. Emissions from fossil fuels come from an ancient carbon circulation, but add to the current circulation.
There are several approaches which could be used to further reduce greenhouse emissions in the ACT. Amongst them:
- Increase use of renewable energy (the Sustainable Energy Development Authority in New South Wales, in conjunction with CSIRO, has used a wind power mapping program to locate the most appropriate areas for wind power in New South Wales and the ACT. The Wind Atlashas identified at least three possible sites for wind-power generators around the ACT, at Braidwood, Yass and Lake George.)
- Further encourage use of solar power. Solar water heaters are cost-effective in Canberra, but have a large up-front cost. The ACT Government’s Solar Hot Water Rebate Scheme encourages greater use of solar but, as of September 2003, only 430 households had taken up the offer, and funding remained for more than 1000 further households. It seems that the funding offered per household may not be sufficient incentive.
- Increase penetration of methane for home heating and, as condensed natural gas, for vehicles.
- Promote more public transport usage.
- Improve the energy efficiency of residential and commercial buildings. However, this may have implications for indoor air quality. The house design rules in European nations with a pattern of hot summers and cool winters similar to Canberra (such as France) may be worth examining for energy efficiency. The mandatory fitting of roof insulation on all new housing and extensions is commendable.
- Retrofit existing houses to increase energy efficiency.
- Offset emissions through plantation establishment in the ACT or on our behalf elsewhere.
- Introduce a scheme similar to the New South Wales Greenhouse Benchmarking Scheme for electricity retailers. The current scheme started in New South Wales on 1 January 2003, under an amended Electricity Supply Act. The scheme requires retailers to reduce emissions by 5% on a per capita basis by 2007, compared to 1989– 90 emission levels, then maintain those levels until 2012. It also includes penalties of $10.50 per tonne of carbon dioxide equivalents (indexed for CPI adjustments) for retailers who do not meet their reduction targets. Legislation in New South Wales now requires electricity retailers to obtain a percentage of the electricity they sell from low-emission sources and/or offset the emissions through promoting energy efficiency or planting trees.
ABS ABS Survey of Motor Vehicle Use, 12 months ended 31 October 2002 9208.0 .
Australian Capital Territory 1999, ACT Greenhouse Strategy , published by Environment ACT, Canberra.
ACT Greenhouse Strategy: 2002 Review of performance and options for the future 2003, Energy Strategies P/L in association with George Wilkenfeld and Associates, NIEIR and SMEC.
Office of the Commissioner for the Environment 2002, ACT State of the Environment Report 2000. , ACT Government, Canberra.
Canberra Times , 13 August 2003.
Gifford RM 2000, Carbon Contents of Above- Ground Tissues of Forest and Woodland Trees, CSIRO Plant Industry, National Carbon Accounting System Technical Report No. 22 .
Mill C, Environment Australia, pers. comm., 13 August 2003. National Greenhouse Gas Inventory < http://www.greenhouse.gov.au/inventory/ >.
NPI 1999, NPI Estimation Technique Manual for Aggregated Emissions from Prescribed Burning and Wildfires , National Pollutant Inventory < http://www.npi.gov.au/ >.
Review of the ACT Greenhouse Strategy Discussion Paper , August 2003 , ACT Government, Produced by Publishing Services for Environment ACT, 2003.