The World Resources Institute (WRI) and World Business Council for Sustainable Development (WBCSD) developed a Greenhouse Gas Protocol to promote an internationally accepted greenhouse gas accounting and reporting standard, to assist companies in their reporting. In order to delineate direct and indirect greenhouse gas emissions, the Protocol defines three 'scopes' for reporting purposes.

• Scope 1 - direct greenhouse gas emissions that are owned or controlled by the company;
• Scope 2 - indirect emissions from the imports of electricity, heat or steam from third parties; and
• Scope 3 - other indirect greenhouse gas emissions.

In order to be broadly consistent with the WRI/WBCSD Greenhouse Gas Protocol methodology, Rio Tinto's greenhouse gas emissions are separately reported as:

• On site emissions that Rio Tinto can exert direct management control over, such as emissions from fuel use, on site electricity generation, anode and reductant use, process emissions, land management and livestock (Scope 1);
• Total emissions, which are on site emissions (Scope 1) plus emissions associated with purchased electricity and steam (Scope 2). However, Rio Tinto currently excludes Scope 2 emissions associated with exported electricity from total emissions; and
• Other indirect emissions, associated with third party transport of our products, offsets (reduction in emissions or external sink), indirect emissions from natural gas and product use (Scope 3).

Relationship between Rio Tinto reporting and the Greenhouse Gas Protocol
Greenhouse Gas Protocol	Rio Tinto method	2003 inventory (million tonnes CO2-e)
Scope 1 emissions	On site emissions	12.7
Scope 2 emissions	Emissions from purchased electricity and steam	12.2
	Emissions from exported electricity	-0.4
	Total emissions	24.5
Scope 3	Other indirect emissions	More details...

We believe that total emissions currently provide the best single measure of our impact, as it enables better comparisons between our operations that generate electricity on site and those that purchase electricity. This measure also enables assessment of some climate change response strategies, such as the Kyoto Protocol, that affect operations with significant indirect emissions from purchased electricity.