Climate change

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Wind energy working at Diavik

Wind turbine in North Canada photograph

In October 2012, Diavik Diamond Mine in northern Canada commissioned a four-turbine wind farm, with the expectation that it would be able to provide 17 Gigawatt hours of renewable energy a year. As the site was too remote to be on the electric grid the mine relied exclusively on diesel generation. In order to keep the diesel generators operating the mine required a large amount of on-site diesel storage. Supplies could only be replenished during a critical two-month period when the seasonal winter ice-road was available.

In 2007, a 50 metre high meteorological tower was installed at the mine site. This helped gather data for a three-year wind resource assessment study. When this revealed that there was a viable wind resource, a pre-feasibility study began. This went on to show that the economics of a wind farm were robust as well. A US$30 million investment was approved by mine owners Rio Tinto and Harry Winston Diamonds. The 2012 winter road was used to transport 60 loads of components for the turbines to the site.

Diavik’s initial goal was to displace ten per cent of the diesel generation, and avoid 12,000 tonnes of greenhouse gas emissions per year. Early results are promising. Although the plan is still to replace ten per cent of diesel generation, short-term and seasonal opportunities have replaced as much as 38 per cent.

Diavik has donated the meteorological tower to a First Nations business consortium in the Northwest Territories, which is investigating the feasibility of wind power around Yellowknife. The company plans to share what it has learned with communities in the area.

Introduction

We recognise that climate change is occurring and that it is largely caused by human activities. It poses significant risks for a broad range of human and natural systems, and is already affecting them. Climate change will create risks and opportunities for our businesses that will affect shareholder value. It will lead to significant changes in the physical environments in which we operate. Over the longer term, climate change threatens the stability of natural, social, economic and political systems, which risks significantly damaging the prospects for our businesses.

Approach

The scale of the necessary emissions reductions and the need for adaptation – coupled with the world’s increasing requirements for secure, affordable energy – create large challenges which require worldwide attention. Our climate change programme focuses on reducing the energy intensity of our operations as well as the carbon intensity of our energy. This includes the use of renewable energy and reduction in emissions intensity from chemical processes. It also addresses emissions from other sources including landholdings.

Setting targets, and regularly reporting against them, is a priority and helps us to manage our performance. We are seeking a substantial decarbonisation of our business by 2050. Following the creation of Pacific Aluminium, the majority of the energy used in Rio Tinto Alcan's smelters is from low-carbon sources.

Reduction of our greenhouse gas (GHG) intensity index is one of seven Group key performance indicators. We are targeting a reduction in the emissions intensity of our products by six per cent by the end of 2013, and by a further four per cent by 2015, compared to 2008.

To achieve this target, we are making major investment in new plants and technology. The operating efficiency of our ongoing operations is also critical.

Results

In 2012, our total GHG emissions were 41.0 million tonnes of carbon dioxide equivalent (CO2-e), a decrease of 2.2 million tonnes from 2011, as a result of decreased production of aluminium, principally the shutdown of the Lynemouth smelter.

Between 2008 and 2012, Rio Tinto’s GHG emissions intensity had reduced 5.1 per cent, largely due to the 2009 divestment of the Ningxia aluminium smelter in China, the 2012 closure of the Lynemouth aluminium smelter and reduced intensity for the alumina commodity with the installation of the Yarwun cogeneration plant and improved performance at the other alumina refineries over the period. We remain on track to achieve our emissions intensity targets in 2013 and 2015.

Greenhouse gas emissions intensity

Greenhouse gas emissions intensity chart from 2006 to 2012
Greenhouse gas emissions intensity chart from 2006 to 2012

Sources of total greenhouse gas emissions

Sources of total greenhouse gas emissions pie chart
Sources of total greenhouse gas emissions pie chart

Please see the Performance data section for a breakdown of greenhouse gas emissions by product group and country.

Total greenhouse gas emissions

Total greenhouse gas emissions chart from 2003 to 2012
Total greenhouse gas emissions chart from 2003 to 2012

The majority of Rio Tinto’s GHG emissions are generated as a result of energy use (electricity, fuel and anodes and reductants) during mining, milling and smelting activities at our sites.

We recognise that there are also significant GHG emissions associated with the transportation, processing and use of our products. In 2012, the three most significant sources of indirect emissions associated with our products were:

  • Approximately 5.4 million tonnes of CO2-e associated with third party transport of our products and raw materials.
  • An estimated 141 million tonnes of CO2-e associated with customers using our coal in electricity generation and steel production.
  • Approximately 374 million tonnes of CO2-e associated with customers using our iron ore to produce steel (these emissions are not in addition to the coal-use emissions above, as some customers use both our iron ore and our coal to produce steel).

Rio Tinto businesses report emissions to regulators in seven countries or regions, including under the Australian National Greenhouse and Energy Reporting (NGER) Act.

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