Where Do Our Emissions Come From?

The previous article in the series explained how global warming is caused by greenhouse gases such as carbon dioxide. In its Fifth Assessment Report, the Intergovernmental Panel on Climate Change (IPCC) concluded that the industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to 412 parts per million in the last 150 years, their highest level in 800,000 years.

Closer to home the Victorian Greenhouse Gas Emissions Report 2019 (Figure 1) shows total net emissions and emissions by sector in Victoria from 1990 to 2017. Victoria has set a target of net-zero emissions by 2050 and will legislate interim targets for 2025 and 2030 shortly.

 

Figure 1: Victoria’s emissions by sector

 

The major sources of greenhouse gas emissions in Victoria are electricity generation (mainly brown coal powered generation) and transport.  The area that demonstrates carbon capture possibilities is LULUCF (land use, land-use change and forestry).

Fugitive emissions

 

When looking at Australia’s emissions the impacts of fugitive emissions[1] become apparent as shown in Figure 2. Fugitive emissions are understated.  In late June, the Minister for Energy and Emissions Reduction, Angus Taylor, amended laws to reflect the scientific consensus that fugitive methane – a highly potent but relatively short-lived greenhouse gas – plays a greater role than previously thought.

The improved measurement of fugitive methane is expected to increase Australia’s reported annual emissions by about 3%. The Guardian reported that if the methane emitted in Australia was measured according to the latest science it would increase Australia’s annual emissions by more than 50 million tonnes a year, the equivalent of Sweden’s total annual carbon emissions.

 

Figure 2: Australia’s emissions by sector

Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to the greenhouse gases produced by human activities. In the next article we look at what we can do to slow the change and why it is critical to make the effort.

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[1] From the production, processing, transport, storage, transmission and distribution of coal, crude oil and gas