Global Warming and Carbon Dioxide

Proponents of the Global Warming theory state that the previous decade was the warmest decade on record. Moreover, they claim that each decade in Australia since the 1940's was warmer than the previous decade and they blame this global warming on human activity that has increased the concentration of Carbon Dioxide (CO2) in the atmosphere. Their fear is that if left unabated, global warming will continue to accelerate as the polar caps melt, reflecting less sun light back into space, and the perma-frost melts releasing vast amounts of methane into the atmosphere.

Sceptics claim that climate data indicating global warming over the last 50 years or so is wrong or that it is part of a natural cycle. They also point out that the world has known prolonged periods that have been warmer than present and prolonged periods that have been cooler than present.

Prior to the industrial revolution, atmospheric levels of CO2 were at about 220 PPM (Parts per Million). This has now increased to about 330 PPM with the expectation that this will continue to rise unabated under a Business As Usual (BAU) scenario. Two targets have been proposed to cap the increase of atmospheric CO2: a Moderate Action target of 550 PPM and an Ambitions Action target of 450 PPM. It is interesting to note that most climate change advocates believe 450 PPM is the tipping point for catastrophic climate change.


Global warming is predominantly blamed on CO2 although a number of other gases, notably Methane (CH4) are also thought to contribute. For the sake of convenience, the global warming potential of all gases is compared to CO2 and referred to a Carbon Dioxide Equivalent CO2e.

Total global emissions over the 2010 calendar year were thought to be about 45GT of CO2e. It is expected that the BAU scenario will see this increase to 95 GT by 2050. Alternatively, the Medium Action target would bring this back to 35 GT by 2050 while the Ambitions Action target would bring this back to 20 GT by 2050.

Australia's emissions over the 2010 calendar year were about 575 MT which can be broken down across the following sectors:

Industrial Process 5.3%
Electricity Generation 34.7%
Other Stationary 15.0%
Transport 14.4%
Fugutative Gases 5.6%
Agriculture 15.7%

We are the world's highest emitter of greenhouse gases on a per capita basis; however, Australia only represents 1.3% of the world's total emissions.

Australia's Targets

Australia has emission targets for the year 2020 and 2050. Both of these targets are set relative to our emissions in the year 2000, i.e. 533MT CO2e. There is some ambiguity with the target for 2020. On occasion this target is quoted as 'at least a 5% reduction on year 2000 emissions' while other publications commit to a 20% reduction against emissions in 2000. The target for 2050 is a reduction of at least 80% against year 2000 emissions.

It is important to note that these targets make no allowance for increased population growth or increasing business activity. Thus, per capita emissions will have to drop by 90% or so depending on population growth. However, not all carbon savings will need to be made within Australia. Current policy allows Australia to purchase carbon credits from off shore. This allows us to purchase the notional carbon savings made by projects implemented in other countries.

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