The smelting of aluminium is a very energy intensive process – which is why over 80 per cent of smelting greenhouse gas emissions are what are called indirect (electricity-related) emissions. The remaining 20 per cent of emissions come from direct (on-site) emissions plus the emissions associated with the production of alumina.

The greenhouse gas intensity of Australian primary aluminium production, not including emissions from alumina refining which are considered separately, remained steady at 15.6 tonnes of CO2-e per tonne of aluminium in 2010, compared to 15.6 tonnes in 2009 and 15.9 tonnes recorded for 2008.  

In 2010 direct emissions of greenhouse gas equivalents (PFCs, carbon inputs, fuels) were at 2009 levels on an intensity basis, 63 per cent lower than in 1990. PFC emissions have been reduced by a further 10 per cent over 2009, and 96 per cent per tonne of aluminium since 1990.

Australian smelters are continually striving to reduce PFC emissions through the implementation of operational best practice and improved technology wherever possible – with the ultimate goal being the elimination of PFC emissions from the process.

Total direct greenhouse gas emissions from Australian aluminium smelters were reported as 3.64 million tonnes CO2-e in 2010, down 0.4 per cent compared to 2009 and well down on the 1990 level of 6.26 million tonnes. Direct emissions per unit of production were 1.88 tonnes of CO2-e per tonne of production, slightly (0.2 per cent) higher than in 2009 and 63 per cent lower than 1990 levels.

Emissions from the purchase of electricity have risen 0.4 per cent on an intensity basis since 2009. These indirect emission levels are closely linked to production and are therefore sensitive to economic conditions.

Since 1990 aluminium production increased by 56 per cent whilst total indirect emissions have risen by only 33 per cent. On an intensity basis, indirect emissions were down 15 per cent on 1990 levels.

Indirect emissions also arise from the consumption of alumina in the smelting process, with around two tonnes of alumina required to produce one tonne of aluminium. At current rates this is equivalent to around 1.5 tonnes CO2-e per tonne of aluminium produced. These emissions are included in our reporting of alumina emissions (below) and not added to the aluminium results to avoid double counting.