"We understand that there is a social problem (with divorce), but now we're seeing there is also environmental impact as well on the footprint." Senator Fielding, who came from a family of 16 children, has been married for more than 20 years himself.

He quoted from a US report he described as "reputable". "Mitigating the impacts of resource-inefficient lifestyles such as divorce helps to achieve global environmental sustainability and saves money for households," Senator Fielding quoted. The Federal Government has agreed to investigate Senator Fielding's concerns.

Ross Carter from the Environment Department told the hearing he had not read the US report, but would take action. "Certainly now that we're aware of it we will discuss that with other agencies," he told the estimates committee hearing.

The government had not measured the impact of divorce on Australia's greenhouse gas emissions. Divorce would be a factor in decreasing the efficiency of housing, Mr Carter noted. "I would imagine that the sort of information that you're quoting from that study would be another factor that would have increased the usage of housing space and decreased the efficiency of that usage," Mr Carter said.

Senator Fielding is one of seven balance-of-power senators in the upper house. AAP