2.2 Greenhouse gas emissions

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Priority Rating: 1

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Description

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Life on Earth is made possible by the 'greenhouse effect', a process in the atmosphere that creates the relatively warm environment near the Earth's surface. About 70% of incoming solar radiation is absorbed by the Earth, warming the land, oceans and atmosphere and providing energy for life forms. The remainder is reflected back into space. Some of the reflected radiation is absorbed by certain gases (known as greenhouse gases) in the atmosphere, trapping heat near the surface layers of the atmosphere (Bureau of Meteorology, 2003). This is the greenhouse effect and without it, the Earth would be considerably cooler. The amount of greenhouse gases in the atmosphere affects how much heat is absorbed. The major greenhouse gases are carbon dioxide, water vapour, methane, nitrous oxide and ozone.

Since the industrial revolution (late 1700s) human activities have led to an increase in the concentration of greenhouse gases in the atmosphere, contributing to an 'enhanced greenhouse effect'. The Earth's climate has demonstrably changed on both global and regional scales since the pre-industrial era: global average air and ocean temperatures have warmed; global mean sea level has risen and there has been widespread melting of snow and ice (Intergovernmental Panel on Climate Change, 2007). These changes have already affected hydrological systems and terrestrial and marine ecosystems in many parts of the world, including WA. The increase in greenhouse gas concentrations is largely due to fossil fuel use (such as oil, coal and natural gas), widespread land clearing, and agricultural activities (Intergovernmental Panel on Climate Change, 2007). The main greenhouse gases generated by human activities are carbon dioxide, nitrous oxide, methane and 65 other gases termed 'halocarbons' (Bureau of Meteorology, 2003). Greenhouse gases can remain active for centuries and it is expected that even if atmospheric concentrations were stabilised, warming of global climate and sea level rise would continue for centuries (Intergovernmental Panel on Climate Change, 2007). However, climate modelling indicates that the scale of climate change and associated impacts will be substantially greater if greenhouse gas concentrations continue to rise (Intergovernmental Panel on Climate Change, 2007).

Scientists warn that reductions in annual global greenhouse gas emissions of about 60% by 2050 are needed to stabilise atmospheric concentrations (Coleman et al., 2004). The 1997 Kyoto Protocol (which came into effect on 16 February 2005) imposed binding, quantifiable emission targets for signatory countries. To date, Australia has not ratified the protocol, but the Government of WA and other state and territory governments support its adoption. The Commonwealth Government has committed to meeting Australia's target under the protocol - stabilising greenhouse gas emissions at 108% of 1990 levels between 2008 and 2012. In 2005 national greenhouse gas emissions were 102.2% of 1990 levels (Australian Greenhouse Office, 2007a).

Objective

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• To reduce WA's greenhouse gas emissions.  

Condition

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Indicator A7: Current atmospheric concentrations of greenhouse gases.

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The concentration of greenhouse gases over the last few decades has been increasing (Figures A2.1, A2.2 and A2.3). Atmospheric concentrations of carbon dioxide have increased approximately 15% and nitrous oxide has increased 7% over the last 30 years (Figures A2.1 and A2.2). Methane has increased about 17% over the same period, but its concentration has stabilised over the last five years or so (Figure A2.3). The stabilisation of atmospheric methane concentration is largely due to a decline in anthropogenic emissions. Since 1999 the anthropogenic sources have begun to rise again, but this has been offset by the decline in methane emissions from wetlands (resulting in a likely overall increase in methane emissions again) (Bousquet et al., 2006). Data on atmospheric concentrations of pollutants is collected at Cape Grim in western Tasmania (which has very good air quality) and forms the baseline for measuring atmospheric greenhouse gas concentrations for the whole of Australia.

Figure A2.1: Monthly averaged atmospheric concentrations of carbon dioxide at Cape Grim Tasmania.

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Data source: CSIRO Atmospheric Research and Australian Bureau of Meteorology - Cape Grim Baseline Air Pollution Station monthly averaged atmospheric carbon dioxide.

Figure A2.2: Monthly averaged and air archive atmospheric concentrations of nitrous oxide at Cape Grim Tasmania.

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Data source: CSIRO Atmospheric Research and Australian Bureau of Meteorology - Cape Grim Baseline Air Pollution Station monthly averaged atmospheric nitrous oxide. Note: Air archive data are indicated in black, April 1978 to May 1984. 

Figure A2.3: Monthly averaged and air archive atmospheric concentrations of methane at Cape Grim Tasmania.

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Data source: CSIRO Atmospheric Research and Australian Bureau of Meteorology - Cape Grim Baseline Air Pollution Station monthly averaged atmospheric methane. Note: Air archive data are indicated in black, April 1978 to May 1984.

Indicator A8: Historical atmospheric concentrations of greenhouse gases.

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Measurements of historical atmospheric concentrations in greenhouse gases put the recent trends observed in these gases into perspective. Modelling data based on ice core samples show the relatively stable atmospheric concentrations of these gases before the 19th Century and an exponential rise over approximately the last 200 years (Figure A2.4). Since the beginning of the industrial revolution, the amount of carbon dioxide in the atmosphere has increased by 33%, methane levels have increased 100% and nitrous oxide levels have increased by 15% (Western Australian Greenhouse Taskforce, 2004). The atmospheric concentration of carbon dioxide in 2005 far exceeds the natural range over the last 650 000 years (Intergovernmental Panel on Climate Change, 2007). The rate of increase in concentration of these gases is significantly faster than any natural rates of variation in recorded history.

Figure A2.4: Atmospheric concentrations of carbon dioxide, methane and nitrous oxide over the last 1000 years.

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Data source: Bureau of Meteorology (2003). Note: Based on measurements from Antarctic ice cores and, since the 1970s, analyses conducted at Cape Grim Baseline Air Pollution Station. Radiative forcing is a measure of the influence the gas has in altering the balance of incoming and outgoing radiation, and is measured in watts per square metre. Positive forcing tends to warm the surface while negative forcing tends to cool it.

Pressures

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Indicator A9: Trends in total greenhouse gas emissions.

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Greenhouse gases vary in their capacity to induce global warming, and therefore the warming potential of each gas has to be taken into account when assessing its effects. This common measure is called carbon dioxide equivalent (CO₂-e). In 2005, WA's greenhouse gas emissions were 66.6 million tonnes of CO₂-e, a 17% increase compared to 1990 levels (Figure A2.5). The State's proportional contribution to national greenhouse gas emissions also increased from 10.4% in 1990 to 11.9% in 2005.

Figure A2.5: Western Australia's greenhouse gas emissions, 1990-2005.

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Data source: Australian Greenhouse Office (2007b). Note: This figure depicts greenhouse gas emissions in carbon dioxide equivalents (CO₂-e).

Most of WA's greenhouse gas emissions are linked to the energy and agricultural sectors (Table A2.1. The energy sector (including stationary and transport energy) was responsible for 74% of WA's emissions in 2004 and increased by 58% between 1990 and 2005 to 49 million tonnes CO₂-e. About half of the increase was from growth in electricity and heat production, petroleum refining, manufacture of solid fuel and other industries (Australian Greenhouse Office, 2005; Government of Western Australia, 2005). WA has a large number of energy-intensive, export-oriented industries including oil and gas, minerals, bauxite refining and iron ore production. With continued growth expected in these industries, increasing emissions from the energy sector are anticipated (Government of Western Australia, 2005).

Transport energy consumption generates about 19% of emissions from the energy sector (and 14% of overall emissions), due to WA's overwhelming reliance on motor vehicles for moving people and freight. This is exacerbated by historical patterns of low density urban development and the vast distances between settlements in WA (see 'Transport').

WA's agricultural sector produces approximately 19% of the State's greenhouse gas emissions, most of which are from methane generated by livestock and the burning of savanna grasslands. Emissions from the land use, land change and forestry sector declined markedly (about 115%) between 1990 and 2004, due to reductions in land clearing and an increase in the area of plantations. The reduction in clearing for agriculture represents a one-off accounting credit against the State's gross emissions unless substantial revegetation occurs. If the overall benefit from this sector is excluded from the State's greenhouse gas emission profile, the State's emissions increased 45% (as opposed to 17%) over this period.

If current trends in WA's greenhouse gas emissions are projected forward to 2008, there is expected to be an increase of 39% on the 1990 baseline figure compared to an 8% 'allowable increase' (Australian Greenhouse Office, 2005). WA is therefore in a challenging situation for reducing emissions, particularly when considered in a global context. This challenge is exacerbated by the nature of WA's economy, which is primarily focussed on trade-exposed export industries, mostly with high emissions intensities. However, WA is well placed to take action on reducing greenhouse gas emissions through development of alternative energy sources (e.g. wind, solar), improving energy efficiency and offsets (e.g. tree planting to offset carbon dioxide emissions).

Table A2.1: Western Australia's greenhouse gas emissions.

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Data source: Australian Greenhouse Office, 2007b. Note: The 'Solvent and other product' and 'Other' categories are not relevant in WA. However, they were included to make this table consistent with the national and international format for greenhouse gas emissions reporting.

Indicator A10: Trends in per capita greenhouse gas emissions.

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Australia's greenhouse emissions constitute about 1.5% of global emissions. However, Australians have the highest greenhouse gas emissions per capita for industrialised nations (Figure A2.6). Some of the main reasons for Australia's high per capita emissions include the reliance on greenhouse-intensive fuels for electricity generation, extensive use of passenger and freight transport over long distances and the extremely high energy usage of the aluminium smelting industry (Turton, 2004).

Figure A2.6: Greenhouse gas emissions per capita for selected industrialised countries (Annex I), measured in millions of tonnes of carbon dioxide equivalent.

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Data source: Turton (2004).

WA's average per capita greenhouse gas emissions are considerably higher than for Australia (Figure A2.7). This can be attributed largely to WA's high level of economic output relative to population and the heavy emphasis of the State's economy on resources and energy development and exports. Average per capita emissions in WA decreased slightly between 1990 and 2005 to 33.1 tonnes CO₂-e. This decrease is largely a function of economic restructure and reductions in land use clearing over this period.

Figure A2.7: Net greenhouse gas emissions per capita for Western Australia and Australia, 1990-2005.

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Data source: Australian Bureau of Statistics (2006a), Australian Greenhouse Office (2007a & 2007b). Note: This figure depicts greenhouse gas emissions in carbon dioxide equivalents (CO₂-e) per capita.

WA's greenhouse gas emissions relative to the level of economic output decreased by 37% between 1990 and 2005 (Figure A2.8). This decrease is consistent with the national trend which is attributed to emissions management actions across sectors, reductions in land use clearing and structural changes in the economy (Australian Greenhouse Office, 2006).

Figure A2.8: Net greenhouse gas emissions per dollar of gross state product or gross domestic product for Western Australia and Australia.

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Data source: Australian Bureau of Statistics (2006b); Australian Greenhouse Office (2007a & 2007b). Note: This figure depicts greenhouse gas emissions (in carbon dioxide equivalents (CO₂-e) per dollar of gross state product (GSP) or gross domestic product (GDP).

Current responses

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Commonwealth Government programs: The Australian Greenhouse Office delivers programs such as implementing targets from the United Nations Framework Convention on Climate Change and the Kyoto Protocol, the National Greenhouse Gas Inventory, implementing the National Carbon Accounting System, and working with industry on the Greenhouse Gas Abatement Program, Greenhouse Challenge Program and the Greenhouse Friendly initiative, to encourage industry action to abate greenhouse gas emissions. The Commonwealth Government has also joined the Asia-Pacific Partnership on Clean Development and Climate (also known as AP6) along with the USA, China, India, Japan and South Korea. The partnership aims to reduce greenhouse gas emissions through the use of clean technology, and exploring ways to reduce the greenhouse intensity of the economy, build capacity and engage the private sector.

State Government programs: a Greenhouse Taskforce was established in 2002 and later released the Western Australian Greenhouse Strategy (Western Australian Greenhouse Taskforce, 2004).The strategy aims to guide State efforts to reduce greenhouse gas emissions and to respond to opportunities and challenges generated by climate change. A Greenhouse and Energy Task Force has recently released a report providing recommendations to manage greenhouse gas emissions from the stationary energy sector in the short term, and to investigate the feasibility of long-term greenhouse gas emissions reduction, emissions trading, energy conservation initiatives and on-ground rules for greenhouse offsets.

Local government: the 'Cities for Climate Protection' is an international organisation that has been established to help local governments integrate greenhouse gas mitigation strategies into their decision-making processes.

Guidance statement for minimising greenhouse gas emissions: the Environmental Protection Authority released the Guidance Statement for Minimising Greenhouse Gas Emissions in 2002 (Environmental Protection Authority, 2002). It provides guidance about considering greenhouse gas emissions in environmental impact assessments. However, the EPA cannot demand that proponents of projects or industries releasing greenhouse gases offset those emissions or comply with targets (Environmental Protection Authority, 2006).

Greenhouse Challenge: this program provides an opportunity for businesses and industries to demonstrate commitment to reducing emissions of greenhouse gases by calculating their greenhouse gas emissions, implementing reduction measures and maintaining independent verification.

Carbon sequestration: policies on technical and regulatory issues for sequestration of carbon below ground (geosequestration) or in vegetation (biosequestration) are being developed.

Implications

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Greenhouse gas-driven climate change is a global issue that will have significant implications for WA's environment, society and economy (see 'Climate Change'). Ongoing increases in greenhouse gas emissions are likely to impact the WA economy, particularly with the likely establishment of carbon trading. Until Australia ratifies the Kyoto Protocol, WA will be unable to participate in, or benefit from, international trading schemes. Quantifying the cost of climate change is complex. The environmental cost of greenhouse gas emissions is largely excluded from the price of goods and services. This provides little incentive for investment in reducing greenhouse gas emissions or in developing greenhouse mitigation technologies. Until Australia recognises this shortfall, the country will fall behind in developing new and sustainable solutions for addressing greenhouse gas emissions.

Suggested responses

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2.4 Establish a legislative framework to achieve greenhouse gas emission reduction targets.  

2.5 Establish a target to reduce emissions by at least 60% below 1990 levels by 2050 and establish interim targets for 2010, 2020, 2030 and 2040.

2.6 Establish a 20% renewable energy target for the State. 

2.7 Develop standards for carbon offsets to ensure their integrity and to support a carbon trading market.  

2.8 Establish a carbon trading market, with a preference for participating in a national emissions trading scheme. 

2.9 Implement all actions of the Western Australian Greenhouse Strategy, including a comprehensive review and update by the end of 2008. 

2.10 Reduce the greenhouse gas intensity of the State's economy: emission reduction strategies and long term targets need to be developed for each sector of the economy.

2.11 Implement the recommendations of the WA Greenhouse and Energy Taskforce report: Strategies to Reduce Greenhouse Gas Emissions from the Western Australian Stationary Energy Sector. 

2.12 Undertake a comprehensive review of energy subsidies and remove subsidies that increase greenhouse gas emissions.