Christiana Figueres, who ran negotiations for the historic Paris Agreement in 2015 at the UN, said Australia had ignored its boundless potential as a renewable energy producer over internal political division.

“The climate wars have been going on in Australia for over a decade. They are in such a suicidal situation because Australia … holds such promise with renewable energy,” she said during prerecorded remarks to the Australasian Emissions Reductions Summit.

Ms Figueres has been a consistent critic of Australia’s approach to climate policy. In 2018, she called on Australia to phase out coal.

She said no country had “as much sun potential as Australia” but it had been hampered by a “completely unstable, volatile, unpredictable stand on climate change”.

Prime Minister Scott Morrison has resisted calls to commit to a net zero emissions target by 2050, but has consistently claimed Australia was “meeting and beating” its obligations under the Paris Agreement.

The government had argued it was entitled to use so-called carry-over credits from overachieving on the Kyoto Protocol to meet its Paris targets.

Although their use is not explicitly banned under the terms of the Paris Agreement, Ms Figueres has lashed it as “cheating”.

“It is just a total lack of integrity and not something that does Australia proud,” she said.

In a speech to the Business Council of Australia last week, Mr Morrison flagged a potential reversal in the policy, saying the government aimed not to use the credits.

“We will only use that carry-over … to the extent that it is required,” he said.

“Let me be very clear: my ambition (and) my government’s ambition, is that we will not need them.”

Independent MP Zali Steggall, who has called for Australia to adopt a net zero 2050 target, has urged the government to heed Ms Figueres’ warning.

“Australia is going to be at the forefront of suffering from the impacts of climate change and we saw that last summer,” she said.

“Australia has so many natural resources and opportunity to be a superpower in a low-emissions world, but instead we have a handbrake on at the moment.

“Countries are getting on with the job to transition to low emissions. State ministers are putting in place ambitious plans in the energy sector, but the federal government is sitting on its hands and we’re not at the table.”

Ms Steggall’s bill was introduced to parliament last month, and includes a net zero emissions target by 2050. It has gained support from the Greens, a number of senate crossbenchers and more than 100 Australian businesses.

She also called for the establishment of an independent climate change commission, and the rollout of risk-assessment plans.

US President-elect Joe Biden has committed to rejoining the Paris Accord as part of a push to hit net zero emissions by 2050. Federal Labor has argued his election is a chance to reset the nation’s climate policy, urging the government to commit to adopt the same target.