The prime minister, Scott Morrison, has released the government’s plan to reach net zero emissions by 2050 and updated Australia’s 2030 projection to between 30% and 35% as he prepares to fly to Glasgow for a United Nations climate summit.

Morrison on Tuesday hailed the plan as a “practical way” to neutralise Australia’s emissions by 2050 but the plan showed almost a third of the abatement task is comprised of cuts via unspecified “technology breakthroughs” and “global trends” while a further 20% will be achieved through unexplained offsets.