Clean water is a crucial ingredient in most homes.
However, a study published this week found that the amount of water used for the cleaning process is a major driver of climate change.
Clean water acts as a buffer against the effects of climate warming and as a reservoir of carbon that can be sequestered.
That means if we reduce water use, the amount that we leave in the ground is reduced.
But the clean water process also means the carbon from it is being stored in the soil.
The study by the Australian National University and a team from the University of Melbourne found that a single water-related task can produce a massive carbon emissions hit.
“We found that if you use enough water for a task, the carbon in the water is being released into the atmosphere,” said Dr Tim Womersley, lead author of the study.
“But if you’re using less water than you used for a different task, you’re also reducing the carbon release.”
Dr Womers, from the School of Chemistry and the School, said that reducing water use in homes had a number of impacts.
“The more you use water, the more water you’re releasing into the environment,” he said.
“So in some ways it’s an environmental pollutant, it’s a greenhouse gas and it’s one of the things that’s going to have a major impact on climate change.”
The researchers analysed the effect of water use on soil carbon over a number, of different tasks.
For example, they took soil samples and collected them in different locations.
Each soil sample contained a different amount of carbon.
“For each task, we also compared soil carbon concentrations over time,” said Womers.
“There was no overall trend for carbon in soil across the tasks.
So if you used more water than for a particular task, your soil would produce more carbon.”
The study used soil samples from different homes and the researchers compared the carbon content of different soil types.
“Some soil samples had a higher amount of soil carbon than others,” Dr Womer said.
The researchers then compared the soil carbon levels between the different home samples to the carbon levels in the atmosphere.
The carbon in a single sample was measured in the air as a percentage of the total carbon in that soil.
For some tasks, the researchers could measure soil carbon as a proportion of the carbon present in the total soil.
“In general, soil carbon is a more stable carbon in soils than other carbon compounds,” Dr John Strom, a research fellow at the School and one of those involved in the study, said.
It means the researchers were able to show that carbon in one home can be transferred to the atmosphere over time.
“When you have more carbon than you have water in your soil, that can lead to increased atmospheric carbon dioxide levels,” he added.
Dr Strom said that soil carbon has a range of biological uses, including photosynthesis and biofuels.
“It’s really important for agriculture to have an adequate supply of organic matter, because soil is an important part of the food chain,” he explained.
“That’s why organic matter is very important to the food system and to the biosphere.”
Dr Stom said that for the study to be conclusive, they needed to find the carbon released into soils over a long period of time.
However he said the carbon stored in soil in a given home was very low.
“You’d be surprised at the amount [of carbon] that you can remove in a year if you had to take a lot of water out of the soil,” he noted.
“As a rule of thumb, we think that a home with only about 100 square metres of soil can release about 0.2 kilograms of carbon per year.”
“We’re looking at soils that are between 1 and 5 millimetres in size,” he continued.
“If you take a hectare, then it can take a year for that soil to have the same amount of CO 2 as it would have in a whole house.
So it’s pretty small.
So we’ve taken a very conservative approach, but it’s very promising.”
This study found that for many tasks, using more water for the task resulted in higher carbon emissions.
But it’s important to remember that the task itself is a very small part of a household’s carbon footprint.
“To be able to see the carbon footprint of these tasks and the effect it has on a household, we really need to look at how much water they use for that task, because they have a big effect on the carbon emissions that are going to come out of that household,” Dr Stem said.
But he added that if a task had a high carbon impact, the water-use technique could help address it.
“I think it’s really promising, and we really hope that it will be adopted more widely,” he concluded.