Labor’s state conferences in NSW and Tasmania have backed more ambitious climate change action, maintaining pressure on their  federal counterparts to stick with a carbon price policy.

Delegates at weekend conferences in both states backed a motion calling on the party’s leadership and organisation to take immediate steps to achieve a minimum reduction of carbon emissions of 19 per cent of 2000 levels by 2020.

“It’s an emphatic statement by the largest branch of the Labor Party,” said Luke Foley, Labor’s leader in the NSW upper house and environment spokesman. “Labor is committed to decisive action on tackling climate change."

The 19 per cent goal matches the ambition recommended by the independent Climate Change Authority to bring Australia in line with international efforts. Australia’s bi-partisan current target is to cut 2000 emissions by at least 5 per cent by decade’s end.

Federal climate change spokesman Mark Butler said earlier this year he also supported the authority’s goals although the target is yet to become party policy.

Opposition leader Bill Shorten, though, continues to back climate action despite this month’s repeal of one of the Gillard government’s signature policies, its carbon price. The Coalition had campaigned for almost five years against a carbon tax, calling it a “wrecking ball” through the economy, and has pledged to introduce an alternative policy of paying polluters to curb emissions – if it can get Senate approval.

“How is that they can believe in a price signal to punish the sick and the vulnerable but not to punish polluters?” Mr Shorten told the NSW ALP conference over the weekend. “They love freedom so much they've made pollution free.”

“Delegates, Labor will fight and fight and fight again for real action on heat trapping greenhouse gases,” Mr Shorten said.

Clean energy will remain central to NSW Labor’s climate policies, Mr Foley said. The party voted on Sunday to oppose any reduction in the national Renewable Energy Target, which mandates the minimum supply of 41,000 gigawatt-hours of solar, wind and other renewable energy sources by 2020.

"It's great to see rank and file Labor members in NSW showing the party the way ahead on climate policy,” Kate Smolski, chief executive of the NSW Nature Conservation Council, said. “I hope the ALP's leadership has the courage and vision to adopt policies that responds adequately to the climate change emergency that we are facing."

Tasmania’s state ALP conference matched NSW in supporting the 19 per cent reduction goal for carbon emissions. It also joined NSW in backing the motion to pursue “early adoption” of targets to slash 2000-emission levels by 40-60 per cent by 2030.

"“Tasmania is being hit hard by the Coalition’s assault on the environment," Labor Senator Lisa Singh told Fairfax Media.

“Acting on climate change is imperative to Labor’s policy reform agenda and our nation’s future," Senator Singh said. “To put it bluntly, Labor gets the science whilst the Liberals are burying their heads in the sand of denial."

Federal Greens leader Christine Milne welcomed the moves by the state ALP conferences: “Now it’s up to the federal Labor party to come into line with what the science tells us and put a target in its (emissions trading scheme),” Senator Milne said. “We need much more ambitious targets for reducing pollution if we are to have any hope of mitigating the costs of global warming like extreme storms, drought and flood.”