Consider whole-of-life emissions when making infrastructure decisions.
As we make decisions on the infrastructure in which we invest, we need to consider the whole-of-life carbon emissions associated with infrastructure in our business cases.
Carbon is created in the production of many construction materials including asphalt, cement, steel and aluminium. The heavy machinery used to build and decommission infrastructure also emits carbon. The production of cement and steel are amongst the largest carbon-emitting processes on earth. Per tonne produced, steel emits roughly 1.9 and cement emits roughly 0.8 tonnes of carbon emissions.98 These embodied emissions can be very high in infrastructure projects due to the use of carbon-intensive materials.
After construction, there’ll be ongoing emissions from the operations, maintenance and use of infrastructure. Emissions generated from operations, maintenance and renewal are referred to as operational emissions and can include the emissions from the energy used in a building.99 Emissions from third parties using infrastructure are referred to as enabled emissions and can include the carbon emissions generated from driving on a road. Emissions can also arise when removing infrastructure, which we refer to as disposal emissions. Some infrastructure, such as a new hospital, can increase overall emissions. Other projects, such as wind farms, can decrease overall emissions.
A whole-of-life approach to carbon emissions looks at embodied, operational, enabled and disposal carbon emissions over the expected life of infrastructure. For projects that are intended to reduce carbon emissions, there’ll usually be a net increase in emissions during the construction phase that will be outweighed by reductions during the operational phase.
Using a whole-of-life approach to emissions can help us make investment decisions that are consistent with net-zero carbon emissions targets and should be used for projects that reduce and increase carbon emissions. A full consideration of whole-of-life emissions can encourage non-built infrastructure solutions, less carbon-intensive infrastructure options and the use of low-carbon construction materials.100
A government work programme is needed to identify and understand which construction materials and methods produce the least carbon and then review regulations, standards and codes to encourage their use.