Emissions from households’ water use are on a par with aviation. The big cuts and savings they can make are being neglected
- Written by Steven Kenway, Research Group Leader, Water-Energy-Carbon, The University of Queensland
Why is there such a big gap between people, industries and government agreeing we need urgent action on climate change, and actually starting? Scope 3 emissions are a great example. These are greenhouse gas emissions that organisations can influence, but don’t directly control.
Our research[1] has identified the benefits of tackling these emissions in Australia’s urban water sector. If we consider the energy we use to heat water, water costs us far more than we think. It’s an issue of cost of living as well as water supply and energy infrastructure.
In Victoria, for example, water utilities are the largest source[2] (about a quarter) of scope 1 and 2 emissions from the government sector. Scope 1 emissions come from activities utilities directly control, such as driving their vehicles. Scope 2 emissions are from the energy they buy.
Our research has found the gains from pursuing scope 3 emissions from the use of water that utilities supply could be about ten times bigger than their planned reductions in scope 1 and 2 emissions.
Extrapolating from Melbourne household data suggests domestic water heating accounts for 3.8% of each person’s share[3] of Australia’s greenhouse gas emissions – on a par with the 4.1% from aviation. Our research[4] indicates that in Melbourne alone a city-wide program to retrofit showerheads could, by reducing water and energy use, have the same impact on emissions as taking tens of thousands of cars off the road.
Such a program would cost much less than all other renewable energy investments water utilities are making. It would also save water users money.
Read more: Australian homes can be made climate-ready, reducing bills and emissions – a new report shows how[5]
How to tackle scope 3 emissions
Water utilities don’t directly control scope 3 emissions, but they could influence what customers do. If they encourage more efficient water use[6], customers use less water[7] and, in turn, less energy to heat it.
Water utilities account for 24% of scope 1 and 2 emissions[8] from the Victorian government sector. While the sector has shown leadership in acting on these emissions, there is very little active accountability for, or even quantification of, scope 3 emissions.
