If Aussie medical expert Professor Barry Walters gets his way, then couples in the country could be paying a tax for having more than two children - to compensate their extra offspring's carbon dioxide emissions.
Professor Walters feels that couples that have more than two kids should be charged a lifelong tax of 5000 dollars a head for every child after their second, and an annual tax of up to 800 dollars.
He criticised the 4000 dollars baby bonus to the new parents and said that it should be replaced by 'baby levy' in the form of a carbon tax in line with the "polluter pays" principle.
"Every family choosing to have more than a defined number of children should be charged a carbon tax that would fund the planting of enough trees to offset the carbon cost generated by a new human being," News.com.au quoted Walters, as saying.
"Sustainable Population Australia suggested a maximum of two, he added.
Prof Walters said that contraceptives like diaphragms and condoms, as well as sterilisation procedures, should attract carbon credits.
"As doctors, I believe we need to think this way," he wrote in a letter to the journal.
"As Australians I believe we need to be less arrogant."
Garry Eggers, director of the NSW Centre for Health Promotion and Research, agreed with suggestions and criticized the former treasurer Peter Costello's request for three children per family - "one for mum, one for dad and one for the country" as too single-minded.
Population remains crucial to all environmental considerations," wrote Eggers.
"The debate (around population control) needs to be reopened as part of a second ecological revolution," he added.
However, Family groups rejected the suggestions, saying larger families used less energy than smaller ones and should not be penalised.