Scott Morrison has taken aim at “internal and global critics” of his government’s climate change policies, accusing activists and the media of spreading “completely false” information about Australia’s stance.

In his first address to the United Nations on Wednesday, the prime minister told world leaders that his government is “taking real action on climate change and getting results”.

Morrison has faced criticism for failing to attend Monday’s climate action summit in New York, with some saying he had not brought forward “a credible climate or energy policy” in Australia.

Morrison said the country was committed to “doing our bit on climate change”, with target of cutting greenhouse gas emissions by 26 to 28 per cent below 2005 levels by 2030.

“Australia’s internal and global critics on climate change willingly overlook or ignore our achievements, as the facts simply don’t fit the narrative they wish to project about our contribution,” he said.

“Australia is doing our bit on climate change and we reject any suggestion to the contrary.”

Ahead of the speech, he said that Pacific leaders he spoke with were often surprised to learn Australia’s environmental policies.

“Oftentimes the criticisms that have been made about Australia are completely false,” he told reporters.

“Criticisms that have been made about Australia are completely false and they’re completely misleading and people have had a prejudiced view … Where do they get their information from? Who knows? Maybe they read it.”

Morrison told the general assembly that Australia is responsible for just 1.3 per cent of global emissions and 5.5 per cent of the world’s coal production, and that it is one of the few countries in the OECD to exceed the targets of their Kyoto commitments.

In the 1997 Kyoto climate conference, Australia was allowed to meet its target more easily with the inclusion of carbon emissions from land clearing in a special article known as “the Australia clause”.

Environment department figures show Australia’s emissions have risen since the Coalition abolished carbon tax in 2014.

The prime minister also suggested that Australia would not update its emission reduction pledge at the 2020 climate conference in Glasgow, even though all countries are expected to do so under the Paris agreement.

“We have our commitments, and we’re sticking to those commitments,” he said.

Morrison also said children had a right “to their optimism” days after climate activist Greta Thunberg condemned world leaders’ inaction in her Monday speech.

“We should let our kids be kids – teenagers be teenagers – while we work positively together to deliver practical solutions for them and their future,” he said.

“We must respect and harness the passion and aspiration of our younger generations, rather than allow others to compound or, worse, facelessly exploit their anxiety for their own agendas.”