Julia Gillard was not across the details of climate change policy early in her prime ministership and should bear some responsibility for the demise of a price on carbon, Greens leader Christine Milne says.

Ms Milne said the former prime minister made a "disastrous" political decision when she conceded her carbon pricing scheme constituted a carbon tax.

Former Prime Minister Julia Gillard. Credit:Bloomberg

The carbon price was abolished last Thursday with the support of all Senate crossbenchers, but the blame game over who brought it down continues. Last week, Labor senators tied the scheme's demise to the Greens' decision to vote against Kevin Rudd's Carbon Pollution Reduction Scheme in 2009.

"A fundamental error occurred when Julia Gillard went on television and conceded that an emissions trading scheme with a fixed price was a tax," Ms Milne told Sky News on Sunday. "That gave Tony Abbott everything he needed to ramp up his campaign on a tax.