Abbott under fire for attack on ETS AS Labor prepares to explain how it will plug a forecast multi-billion dollar budget hole from moving early to an emissions trading scheme (ETS), Tony Abbott has ridiculed carbon pricing as a so-called market based on an invisible substance. The federal government will scrap the fixed carbon price period and bring forward a floating price to assist business and ease living costs for households. It's the first major policy change under the Rudd government and could help Labor diffuse the coalition's dogged attacks around the carbon tax in the lead up to the federal election. Finance Minister Penny Wong on Monday indicated the government would explain within days how it would find offsetting savings to remain budget neutral while moving early to a floating price. But the opposition leader provided a distraction from these tough questions when he blasted the idea of emissions trading during a press conference to criticise Labor's decision. "Just ask yourself what an emissions trading scheme is all about," he said. It is a so-called market in the non-delivery of an invisible substance to no one. Senator Wong said the opposition leader had simply built upon his previous record of calling climate change "absolute crap," and questioned how he could meet with world leaders acting on global warming. She was surprised he'd attacked emissions trading when former Liberal prime minister John Howard had advocated one. "This is an absolute joke and confirms yet again that Tony Abbott is simply not up to being the leader of the nation," Senator Wong told reporters in Canberra. Independent MP Rob Oakeshott joined many others on Twitter to criticise Mr Abbott, reminding him all federal MPs were "visible" two months ago when they voted unanimously to support the science of climate change. The coalition said moving to an ETS didn't change the fact it was still a carbon tax, while the Association of Mining and Exploration Companies said it remained opposed to the whole policy. The Australian Greens were critical of the decision and said Labor should now set more ambitious pollution targets and commit to maintaining the independent Climate Change Authority. "If he keeps that authority, brings (the ETS) forward, and we see a much higher emission reduction target, that will be a start," Greens leader Christine Milne said. The government is yet to set a date for the shift to an ETS, which was initially scheduled for July 2015, but Treasurer Chris Bowen said the government would seek a mandate nonetheless. He warned it wouldn't be a silver bullet for rising electricity prices, but it would make a difference. Mr Bowen would not be drawn on possible targets for offsetting savings but said tough decisions would have to be made as the government remains committed to a 2014/15 budget surplus. The household assistance package linked to the carbon laws however will remain untouched. Australia's 500 biggest polluters currently pay a fixed price of $24.15 per tonne of CO2 emissions, but under a floating price could pay as little as $6 per tonne.