Greenhouse gas emissions (GHG)
Rio Tinto's climate change position requires us to demonstrate understanding and control of the emissions associated with our mining and processing activities. By reducing emissions now we reduce the size of reductions needed in the future and establish knowledge, skill and confidence in moving forward.
A good understanding of emission levels and sources is essential for a well targeted reduction programme. It also enables comparative understanding of our emissions relative to other parts of the product value chain, our peers and our competitors. Our emissions inventory includes all six Kyoto Protocol gases (carbon dioxide, methane, nitrous oxide, sulphur hexafluoride, perfluorocarbons and hydrofluorocarbons). Of these CO2 (91 per cent) and CH4(8 per cent) represent 99 percent of our emissions. Also around 90 per cent of our emissions are associated with energy use, the remainder being associated with methane associated with coal mining, industrial processes and land management.
In 1994 Rio Tinto commenced determining its emissions profile so it can understand and manage its emissions performance. Since then this programme has grown in parallel with external emissions accounting and reduction best practice. Throughout our programme we have strived to remain current, complete and precise:
- Current - Our emissions accounting practices are consistent with the IPCC (Intergovernmental Panel on Climate Change) 1996 guidelines and the 2004 WBCSD/WRI greenhouse gas protocol. To verify this we asked ERM to audit our inventory methodology in 2003 and Ernst and Young in 2005. The results of both audits gave us confidence that our practices are current. Rio Tinto has also worked with Standards Australia in the development of the ISO 14064 greenhouse accounting standards. In addition we are improving our documentation of procedures as the ISO standard requires.
- Complete - There are many hundreds of individual emissions sources within Rio Tinto. A few are very large and contribute the majority of emissions. A number are very small. We try to have our inventory as complete as possible, but for practical reasons have set a cut-off below which individual sources do not need to be measured. We estimate that these omissions, when combined, lead to less than 1 per cent of total emissions - well within accepted completeness guidelines.
- Precision - All measurements, including greenhouse gas emission measurements, have associated uncertainty. We regularly estimate the uncertainty of our inventory using an IPCC methodology. Uncertainty is 4.5-8 per cent, but when comparing changes in emissions between years, drops to less than two per cent. The highest level of uncertainty is associated with the amount of methane emitted during coal mining. We continue to work with others to reduce this uncertainty, but success has been slow.
In addition to emissions reduction for climate change purposes, it makes good business sense to reduce emissions where they are linked to energy use. However, identifying, implementing and sustaining savings is a challenging task. Rio Tinto has a number of programmes to support emissions reductions.
- Greenhouse Gas Standard - All businesses and operations were required by July 2005 to implement Rio Tinto's greenhouse gas standard. The standard requires emissions understanding, study of emissions reduction risks and opportunities and implementation of an action plan. Success at implementing the standard is reported elsewhere in this document. In July we commenced auditing of business performance against the standard. Auditing will continue over the next two years.
- Targets - Rio Tinto's five year greenhouse gas reduction target is four per cent for the second year results.
- Corporate projects - We recognise that corporate sponsorship of energy saving projects make sense where underlying issues are common to a number of businesses and where collective action will make more progress than when businesses are working in isolation. For this reason in 2005 we undertook an Integrated Energy Management Study, and commenced studies of a) benefits of fuel additives to improve fuel efficiency, b) key areas of energy efficiency improvement and c) greenhouse gas reduction opportunities. Progress in these areas will be reported in future years.
Since 2001 we have been collecting initiatives from operations on energy efficiency and greenhouse gas reductions. In 2005 the number of projects increased from 268 in 2004 to 375. The annual savings associated with these projects in 2005 was 1,913 (compared to 1,162 in 2004) Mt CO2-e.
Greenhouse gas emissions abatement cost curves
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