Climate change, greenhouse gas and air emissions


  • Produced Scope 1 (fuels) and 2 (electricity) greenhouse gas emissions of 95,348 tCO2-e
  • Realised emissions of 1,231,750 tCO2-e from customers driving on our networks
  • Continued periodic climate change risk assessments on our assets and new projects in development
  • Measured and reported greenhouse gas emissions for our Sustainability Report and the Australian National Greenhouse and Energy Reporting (NGER) Act
  • Continued compliance with air quality monitoring and management requirements to maintain safe roads and tunnels

Climate change

We recognise that climate change has the potential to impact our business in a number of physical, financial and regulatory aspects.

Transurban’s Enterprise Risk Management Framework covers corporate-wide risks and risks associated with the operation of individual road assets. Climate change risk categories and procedures within the corporate sustainability risk register ensure that these risks are addressed from a number of perspectives including:

  • Physical climate risk – managing the risk of severe climate events that have the potential to damage or impede Transurban assets and projects
  • Environmental impact – managing Transurban’s environmental impacts and the contribution of our greenhouse gas emissions to climate change (actions to address this are discussed in the previous section on energy use and efficiency and further below)
  • Regulatory risk – managing the risk and compliance of emerging legislation relating to climate change

Physical climate risk

Physical climate change impacts include extreme weather events (e.g. wind, rain, snow, heat) and change in temperature and precipitation patterns (e.g. drought) that have the potential to damage infrastructure and reduce its expected lifespan, destroy vegetation and landscaping, increase vehicle break downs and accidents, disrupt traffic flows or lead to road closures.

Physical impacts are mitigated through the design, construction and maintenance of climate-resilient assets. We work with our construction partners to assess climate change risks in the design phase of our major projects so we can take measures to help our assets adapt to future expected climatic conditions.

Transurban completed a major Group-wide climate change risk assessment of all assets in 2010 and 2014, and has since completed individual risk assessments for new assets and major asset upgrade projects.

In FY16, detailed climate change risk assessments were completed for the NorthConnex, Gateway Upgrade North and CityLink Tulla Widening (CTW) projects. Using the latter as an example, Transurban and CPB Contractors worked together to assess the potential impacts of a range of projected climate change scenarios from the present day to 2040, 2070 and 2090.

This included sensitivity analysis of the changes in risk rating under a range of climatic conditions including temperature, heatwave, rainfall, storm surge, wind speed and soil moisture.

The risk assessment was designed to ensure that the asset design, long term operations and maintenance plans would be sufficient to operate under future conditions. Examples of specific considerations included:

  • Ensuring the design specifications of foundations, pavement, drainage and other infrastructure were sufficient to accommodate historical and projected future extreme weather events
  • Identifying the expected lifetime and maintenance cycles of asset components including asphalt pavement, concrete, painted surfaces and how these may be affected by increased temperatures, heatwaves, rainfall and storm surges
  • Identifying indirect risks in the supply chain and broader region, such as the possibility of power supply interruptions in the event of more frequent heatwaves

With design and controls for these risks put in place, it is our assessment that climate change risks are unlikely to materially impact the operation of Transurban assets or increase road maintenance costs within the current concession deed periods.

Regulatory climate risk

An Australian carbon pricing scheme was in place for two years until being repealed in July 2014 in favour of the ‘Direct Action Plan’ which has voluntary participation.

The previous carbon price had a relatively low direct financial impact on the business due to Transurban’s low fuel usage and Scope 1 emissions covered by the legislation. There was potential for indirect cost pressures to be passed on to Transurban by suppliers, particularly emissions intensive industries such as electricity generators and supply costs for emissions-intensive materials such as steel, asphalt and concrete used in road construction and maintenance.

Transurban continues to pay close attention to potential regulatory changes and will assess the impact of any further emerging regulation when required.

Transurban is currently subject to regulatory reporting requirements in Australia under the National Greenhouse and Energy Reporting (NGER) Act, which requires annual reporting of greenhouse and energy data to the Australian government. Reporting under this Act is further described below.

GRI G4 Indicators

  • Emissions DMA
  • Compliance (Environmental) DMA
  • EC2
  • EN15
  • EN16
  • EN17
  • SO2

FY16 Greenhouse Gas emissions

Transurban’s overall emissions

In FY16, Transurban’s total Scope 1 (fuel) and 2 (purchased electricity) emissions were 95,348 tonnes CO2-e (tCO2-e)3.

AirportLinkM7, which was acquired by Transurban in April 2016, has not been included in our FY16 total as it was not fully integrated into our HSE monitoring and reporting systems.

The trend in Transurban’s Scope 1 and 2 emissions is shown below.

Graph above shows only assets under Transurban financial control. Also excludes AirportLinkM7 (to be included from FY17).
3 The total Scope 1 and Scope 2 figure is 101,822 tCO2-e when non-controlled assets (M5 and M7) are included.

Scope 1 emissions

Transurban’s Scope 1 emissions arise from the combustion of fuel in vehicles and generators, and represent around 2 per cent of the total of Scope 1 and 2 emissions.

Scope 2 emissions

Scope 2 emissions from purchased electricity continue to be our largest source of emissions, accounting for around 98 per cent of our total emissions. As a result, electricity usage is a major focus of our energy and emission reduction efforts.

For more information about Transurban’s energy use please refer to the ‘10-in-10’ energy target section previous.

Scope 3 emissions

Our corporate Scope 3 emissions include the following sources:

  • Upstream emissions from fuel refining and supply
  • Upstream emissions from transmission and distribution of electricity
  • Corporate air travel
  • Emissions from waste to landfill

These are not presented in the graph above due to lower control by Transurban and higher variability, particularly in waste quantities with construction and maintenance activity.

Customer vehicle emissions

We also report on the estimated greenhouse gas emissions from customer vehicles travelling on our roads. These emissions are distinct from our corporate Scope 3 emissions since they are not directly related to our business operations.

In FY16, we estimate that vehicles on Transurban roads contributed approximately 1,231,750 tonnes CO2-e on assets under Transurban financial control4.

Vehicles travelling in free-flow traffic conditions generate less greenhouse emissions than those travelling in stop-start traffic due to improved fuel efficiency at cruising speeds. Transurban's roads have been designed and are operated to keep traffic flowing to help reduce congestion and improve travel times in comparison with alternative routes.

Transurban collects and analyses travel-time data from our toll roads as well as adjacent alternative routes operated by government. This includes roadside data captured by our systems directly and independent external data sourced from GPS and mapping data providers. This allows us to assess travel times and identify the travel time savings offered by our assets. Our analysis of travel time and fuel efficiency data confirm that using Transurban's routes in free-flow traffic situations produces less GHG emissions per kilometre than using an alternative route along arterial roads.

A recent environmental review completed in December 2015 for the M5 Southwest Widening project estimated the improvements in travel times achieved by the motorway upgrade reduced vehicle GHG emissions by between 30 to 40 per cent compared to an alternative route during peak hours. It also showed that improved driving conditions from the road widening had reduced vehicle emissions by a further 10 per cent. The full report can be found here.


4 The total customer emissions figure is 1,795,325 tonnes CO2-e when non-controlled assets (M5 and M7) are included.

Construction emissions

Assets under construction and major upgrades managed by contractors are not included in Transurban’s corporate emissions as they are not under our operational control. Nonetheless, we aim to monitor energy use and GHG emissions for these projects.

Transurban’s major Australian project contractors are required to monitor and report on energy and GHG emissions, and track information about construction impacts via the requirement for major projects to be assessed using the Infrastructure Sustainability (IS) Rating Tool.

The IS rating tool includes performance credits for monitoring and reducing operational energy and GHG emissions, and life cycle energy and GHG emissions from the main materials used in road construction (i.e. asphalt, concrete and steel).

For more information about the IS Rating Tool and how Transurban applies it to projects refer to the Infrastructure Sustainability subsection of this report.

National Greenhouse and Energy Reporting

From FY15 onwards, Transurban has reported its greenhouse gas emissions under the Australian National Greenhouse and Energy Reporting (NGER) Act.

Under NGER legislation, Transurban is required to report the Scope 1 and 2 emissions of the facilities over which it has direct ‘operational control’. For FY16 our NGER reporting will include our Australian corporate offices, CityLink, M2, Lane Cove Tunnel, Eastern Distributor, Cross City Tunnel, Gateway Motorway, Logan Motorway, and the Go Between Bridge. This report will be submitted by the end of October 2016.

Our other Australian assets and construction projects where contractors or other entities have operational control are not included for the purposes of NGER legislation. Our USA assets are not subject to this Australian legislation.

Air quality

Air quality is an important environmental measure for our roads. There are specific regulations in place for maintaining air quality within road tunnels and ensuring vehicle exhaust is appropriately diverted via tunnel ventilation systems. Transurban monitors, controls and reports on air quality to ensure conditions both on and near our road tunnels are maintained to a high quality that meets regulatory requirements.

Air quality and emissions measured by Transurban tunnels are reported in the Environment Data Sheet section of this report.

Air quality monitoring upgrade

In an Australian-first, in FY16, we installed state-of-the-art technology in the ventilation outlet monitoring systems in our CityLink tunnels.

Our previous monitoring system required fortnightly maintenance during off-peak times when the tunnel was open. To address the risks associated with this activity - including potential traffic incidents - Transurban implemented a Fine Dust Analysis System which features a new, low-maintenance, light scattering technology. This new approach has reduced the frequency of routine maintenance to three-monthly - coinciding with scheduled tunnel closures, and also reduced associated cost and safety risk. Through installing this technology, we have been able to maintain our air quality monitoring requirements without any impact to service and realising annual savings of about $300,000.

As this initiative introduced new technology, Transurban was required to gain endorsement of the Victorian EPA and their independent auditor. The successful outcomes from a trial of the equipment saw the technology gain the EPA’s endorsement in late 2015, and was subsequently featured at the Clean Air Society of Australia and New Zealand’s Clean Air Conference.

This innovation is being considered for use on our other tunnels.