Households are being warned to expect big jumps in petrol and electricity prices to persuade them to shift to low carbon options. In a draft discussion document, the Productivity Commission estimates carbon prices may need to jump twelvefold to reach the Government's goal of net zero emissions by 2050. The report has 50 recommendations in it to achieve what the Commission's chair, Murray Sherwin, says is a challenging, but achievable, target. While motorists will pay more at the pump, Mr Sherwin told our economics correspondent Patrick O'Meara that higher prices alone won't be enough.