Bloomberg was previously the UN special envoy for climate action between March 2018 and November 2019.

He stepped down shortly before announcing his bid for the Democratic US presidential nomination. He dropped out of the race in March 2020.

The media mogul will support Guterres in “growing and strengthening” a coalition of governments, companies, cities and businesses committing to net-zero emissions by 2050 in line with the goals of the 2015 global climate deal struck in Paris, the United Nations said.

In 2015, nearly 200 countries committed to halt rising temperatures quickly enough to avoid disastrous climate change.

The United Nations in November will stage a crucial follow-up climate summit in Glasgow, Scotland.

By then, countries are expected to commit to make deeper emissions cuts to deliver the goal of the Paris agreement.

The reappointment of Bloomberg aims to “mobilise stronger and more ambitious climate action” in the run-up to the Glasgow summit, the United Nations said in a statement.

New US President Joe Biden has moved to bring the US, the world’s second-largest greenhouse emitter, back into the Paris deal.

Washington formally left the accord last year but its role as a heavyweight in global climate negotiations had already stalled with the 2016 election of Republican President Donald Trump.

Bloomberg “will engage government officials and members of the private sector and civil society to finalise and implement plans, particularly in high-emitting countries, industries and sectors, to vastly accelerate the transition to a clean energy economy”, the United Nations said.

He will also help deliver on Guterres’ call for the “phase-out of coal in industrialised countries by 2030, and all other countries by 2040, underpinned by a just transition for affected communities and workers”, the world body said.