Clive Palmer has repositioned his party’s shift on climate change policy as an economic decision rather than a response to global warming, just days after appearing on a podium beside climate crusader and former US vice-president Al Gore.



Palmer now says his support for an emissions trading scheme sometime in the future is because Gore told him that other countries with trading schemes were likely to impose tariffs on imported goods.



“That is something I wanted to explain to the Australian people … regardless of your position on climate change that is the reality of life,” he said.



“You will have to have an ETS or otherwise you won’t be able to do international trade … that is why we did it. We didn’t want the Australian people to be disadvantaged.”



Similarly he said the Palmer United party had decided to vote against the government’s plan to abolish the Clean Energy Finance Corporation “not on the basis of what it was doing” but because it was “making a profit and employing thousands of people around the country”.



The PUP founder made the comments at a voters’ forum and press conference during an open day held at his Palmer Coolum Resort, where he invited the electorate to see his giant robotic dinosaur park, memorabilia including his car collection and a concert by Dean Vegas, an Elvis impersonator.



Palmer also returned to the arguments he used when he was sceptical about human-induced climate change. He said his personal understanding of the science of climate change was that mankind’s activities since the 1850s meant it was now contributing 3% rather than 2% of all the carbon in the atmosphere. That meant “nature” was still contributing 97%.



“My view is, if that is true … what we need to do is look at what nature is contributing. That is contrary to what most climate change people. So that is where my difference comes in.”



And he said his party had decided to vote against changes to the renewable energy target because the government had gone to the election promising not to change it, and governments should keep their promises.



“There are so many broken promises in the budget. You can’t have a government that goes around breaking promises.”



Asked by Guardian Australia why he had changed his own election policy, which was to make the renewable energy target voluntary – effectively rendering it meaningless – he said that policy had been “developed further”. The party now wanted the RET to stay unchanged until the next election, due in 2016. “It may well be voluntary after 2016, it may not exist after 2016,” he said.



The PUP senator-elect Dio Wang told Guardian Australia he did not accept the idea of global warming caused by humans. Palmer said Gore had “made his comments independently of me”.



While tariff barriers have been talked about during international climate talks, no country imposes them or has concrete plans to do so.



The PUP has said it will back the repeal of the carbon pricing scheme when the new Senate begins in July – but will not support the abolition of the CEFC or the Climate Change Authority and will not back mooted changes to the renewable energy target, which the government has under review.



Palmer has said he will try to introduce a new emissions trading scheme with the price set at zero until other countries take action, but this is almost certain to be defeated in the lower house.

