Mr Howard told media on Sunday that despite going to the 2007 election supporting a trading scheme, he believed there had been a global shift away from that type of action.
Ms Gillard said the federal government's new carbon tax, which will see a $23 per tonne price on carbon before the establishment of a trading scheme, would mean Australia could keep up with the rest of the world.
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"John Howard when he was prime minister was an advocate of moving first," she told journalists in Adelaide on Sunday.
"When he was prime minister he talked to this country about the benefits that can come from being an early mover."
Mr Howard said the global financial crisis and the collapse of the Copenhagen climate change talks meant the debate had altered.
"Some of the views have shifted on the science, people aren't as certain anymore as they were four years ago," he told ABC TV.
Ms Gillard said Australia risked being left behind as the rest of the world moved to a clean energy future.
"He was saying that in 2007 - the truth is standing here today many nations around the world have moved," she said.
"We're not taking now about leading the world, we're talking now about staying up with the rest of the world."
