"The world urgently needs a clear and unambiguous commitment to the 1.5-degree goal of the Paris Agreement from all G20 nations. There is no pathway to this goal without the leadership of the G20," he said in a statement on the G20 ministerial meeting on environment, climate and energy, Xinhua reported.

"This signal is desperately needed by the billions of people already on the front lines of the climate crisis and by markets, investors and industry who require certainty that a net-zero climate-resilient future is inevitable," he said.

Science shows that in order to meet this ambitious, yet achievable goal, the world must achieve carbon neutrality before 2050 and cut dangerous greenhouse gas emissions by 45 per cent by 2030 from 2010 levels. But the world is way off track, said Guterres.

With less than 100 days left before the UN Climate Change Conference in Glasgow, Scotland, he urged all G20 and other leaders to commit to net-zero by mid-century, present more ambitious 2030 national climate plans and deliver on concrete policies and actions aligned with a net-zero future, including no new coal after 2021, phasing out fossil fuel subsidies and agreeing to a minimum international carbon pricing floor as proposed by the International Monetary Fund.

The Group of Seven and other developed countries must also deliver on a credible solidarity package of support for developing countries, including meeting the $100-billion goal, increasing adaptation and resilience support to at least 50 percent of total climate finance and getting public and multilateral development banks to significantly align their climate portfolios to meet the needs of developing countries, he said.

Guterres said he intended to use the opportunity of the upcoming UN General Assembly high-level session to bring leaders together to reach a political understanding on these critical elements of the package needed for Glasgow.