The longer Australia takes to step up to the plate on emissions reduction, the greater the chance of failure, an international expert says.

Time is not on the world’s side says Dave Turk, a former special assistant to US president Barack Obama who now heads up the energy and environment sector of the International Energy Agency.

Between 2014 and 2016 global emissions levelled off for the first time while GDP continued to rise, but any belief it was good news was premature.

Last year global emissions rose by 1.4 per cent in large part to a loss of efficiency gains, including because of a preference for larger cars.

‘Certainly coming from an international perspective, Australia plays such an important role globally, regionally and we really need Australia to be a central part of the solution,’ he said.

Labor’s foreign affairs spokeswoman Penny Wong said Australia’s international reputation and credibility on climate change had taken a massive hit after the Abbott government repealed the carbon price.

A key focus of the summit is action being taken by other major countries including China which rolled out an emissions trading scheme nationally last year.

Senator Wong said the last almost 10 years have been a lost decade for Australia while the rest of the world has moved on.

Australia hasn’t had a durable mechanism for meeting its emissions and climate targets since 2009, she said.

‘Before prime minister (Tony) Abbott was elected, Australia had been building a growing reputation as a forward-thinking and serious contributor to global climate change policy.’

On Tuesday Senator Wong committed to reinstating a Climate Change Ambassador if Labor wins government.

Labor would also broaden relationships with third parties including the Green Climate Fund, Asian Development Bank and particularly stakeholders in the Pacific.

There needs to be constructive internationalism if Australia is to be a serious global player on emissions reductions and addressing climate change, she said.

Labor is also committed to keeping the government’s National Energy Guarantee if it gets the approval of all state and territories by August, but increasing the emissions reduction target to a 45 per cent reduction on 2005 levels by 2030.

Australia’s Paris Agreement commitment is for a 26-28 per cent reduction, while the National Energy Guarantee would legislate a 26 per cent target for electricity.

Bloomberg New Energy Finance head Kobad Bhavnagri told the summit the NEG lacked ambition, transferring the burden of emissions cuts to sectors of the economy that don’t have the technology to decarbonise.