For 50 years, the UN Environment Programme (UNEP) has offered the world a way forward "based on a vision for a better, healthier Earth built on the pillars of international cooperation," Secretary-General António Guterres told a landmark special session on Thursday, commemorating the agency's golden anniversary in Kenyan capital Nairobi.

"The planet was already showing signs of buckling under the weight of humanity" back in 1972 when the agency was founded, he explained to the event in Nairobi via video message.

"In the following decades, UNEP and its partners would work with Member States to combat air pollution, restore the ozone layer, protect the world's seas, promote a green and inclusive economy and raise the alarm about biodiversity loss and climate change."

Mr. Guterres lauded UNEP as illustrating that multilateralism works and can deliver solutions for people and the planet.

UNEP's science, policy work, coordination and advocacy has helped to right environmental wrongs around the world and raise awareness of the critical role that the environment plays in sustainable development.

"That work has never been more important," attested the UN chief.

Pointing to climate disruption, biodiversity and habitat loss, and pollution and waste that threatens societies and life on Earth, he observed that "humanity continues to wage a suicidal war against nature.”

To address this, the top UN Official set out four targets, beginning with the need to protect the most vulnerable, 'who now number in the billions.”

"We need scaled up international cooperation to provide the financial and technical assistance that vulnerable countries and communities need for greater resilience," he said, urging donors and multilateral development banks to "more than double the share for climate adaptation to at least 50 per cent of climate finance by 2024".

Secondly, the UN chief underscored that the world must cut global emissions by 45 percent this decade to reach net zero emissions by 2050.

"This means no new coal.  And no coal finance," he spelled out.

During the UN climate conference (COP26) in Glasgow last year, Mr. Guterres was heartened by South Africa’s announcement of a renewable energy partnership.

He urged all countries that have pledged to get out of coal and that need technological and financial support to undertake equivalent coalitions.  

"Coal needs to be phased out in OECD [Organization for Economic Co-operation and Development] countries by 2030 and by 2040 everywhere else," he argued, adding that "every sector in every country needs to decarbonize this decade, especially the energy and transportation sectors."

(With input from UNEP)