As world leaders prepare to gather for their annual meetings at the U.N. General Assembly, heightened tensions between the United States and Iran threaten to overshadow a summit on global warming.

“Let’s face it, we have no time to lose. We are losing the race against climate change,” U.N. Secretary-General António Guterres told reporters Wednesday. “The imperative to act could not be more clear, and this is exactly why I am convening the Climate Action Summit.”

The summit will take place Monday, and more than 100 heads of state and government are expected to attend. Only those who bring dynamic and concrete plans to mitigate the effects of global warming will be invited to speak.

Guterres, who has made slowing climate change his signature issue, said he expects a number of “meaningful plans” for drastically reducing emissions during the next decade and for reaching carbon neutrality by 2050.

"We will showcase promising initiatives aiming at moving away from coal, putting a price on carbon, stopping subsidies for fossil fuels, and cutting the pollution that damages our health," he said. "And we will highlight the importance of scaling up nature-based solutions, creating cleaner ways in the way we work and societies function, building resilience, protecting people, mobilising finance and promoting decent jobs for a just transition."

The U.N. wants to accelerate action on the 2015 Paris climate accord, which aims to limit the Earth's temperature rise this century to well below 2 degrees Celsius above pre-industrial levels. Experts warn that the Paris commitments are inadequate to avoid the worst impacts of climate change and more ambitious action needs to happen.

Current evidence

"We're seeing that actually, I think, on the ground in real time," said David Waskow, director of the International Climate Initiative at the World Resources Institute. "We have floods, we have major weather events, we have droughts that are showing us what's happening."

While most of the world is on board – 195 countries have signed the Paris Agreement and 186 have ratified it – one of the world's biggest emitters, the United States, announced under President Donald Trump that it would leave the pact. The U.S. decision has not stopped climate action at the state, local and private sector levels.

On Friday, youth climate activists held "strikes" in cities and towns across the globe demanding bolder action from adults. Swedish activist Greta Thunberg, 16, joined youth strikers in New York City, where she will be attending a youth climate summit Saturday at the United Nations.

"The best leadership I've seen so far is actually coming from young people," Deputy U.N. Secretary-General Amina Mohammed told reporters this week. "The future is going to be very different. It will be about them, and they've started now and not tomorrow."

Saudi Arabia attacked

But this collective push for more climate action risks being overshadowed by the latest geopolitical crisis in the Middle East.

On Sept. 14, Saudi Arabia's two most important oil installations were attacked, threatening global oil supplies. Houthi rebels, whom the Saudis are fighting in neighboring Yemen, claimed responsibility. The United States believes their patron, Iran, was the perpetrator.

The attack has dashed growing expectations that there could be a meeting between Trump and Iranian President Hassan Rouhani on the margins of the General Assembly.

Interlocutors, including President Emmanuel Macron of France, had been working on it since the meeting of the Group of Seven major industrialised countries in Biarritz, France, in late August. Trump had repeatedly expressed interest in the possibility, and the firing of his hawkish national security adviser, John Bolton, appeared to eliminate a voice within the administration that would have been against a meeting.

But such an encounter always carried more political risk for the Iranian president than the American one, and the Iranians had said they would consider a meeting only if U.S. sanctions were lifted first.

"So if there is a meeting with President Trump in New York, and the Iranian president gets nothing in return, that photo opportunity might work well for President Trump in the United States for his base. But back in Iran, Rouhani will be attacked as somebody who was naive, who should have never shown up for that meeting, because they will say predictively, 'He's got nothing to show for it’,” said Alex Vatanka, a senior fellow at the Middle East Institute in Washington.

What else to watch for

While these tensions are likely to garner much of the media spotlight, work will be going on out of the public eye in bilateral meetings, at working lunches and at side events to tackle an array of issues from development to health to myriad conflicts.

Trump is also hosting a session Monday morning on protecting religious freedom. Vice President Mike Pence will join him at the event the White House says aims to prevent attacks on people based on their religion or beliefs and ensure the sanctity of houses of worship.

Starting Tuesday, world leaders will take to the large marble podium in the General Assembly hall to talk about the issues that are most important to their governments and peoples.

One of the most anticipated statements will be from the U.S. president, who will speak Tuesday morning.

Trump is in campaign mode this year and he gave reporters a glimpse of where he might go in his speech:

"I'm going to say, 'The United States is the greatest country in the world. It's never been stronger and it's never been better, and they certainly have one of the great presidents in our history.' "

Last year, a similar line about his administration accomplishing more than almost any other administration in the history of the United States garnered laughter from the assembly.

Focus on North Korea expected

Richard Gowan, U.N. director for the International Crisis Group, told VOA that Trump is likely to focus a lot on what he sees as progress on the diplomatic front with North Korea.

"Trump likes to present himself as a peacemaker – he clearly isn't succeeding in that when it comes to dealing with Iran – so the Korean issue is the one that he will strongly emphasise," Gowan said.

North Korea is not sending its foreign minister to New York this year, making any new developments on that issue unlikely during the week.

Others to watch include the debut of British Prime Minister Boris Johnson, who is deep into Brexit, and Brazilian President Jair Bolsonaro, a climate change skeptic. Brazil's Amazon rainforest has experienced devastating fires in recent months.

A late dropout from the lineup will be Israeli Prime Minister Benjamin Netanyahu, whose political future is in limbo after a parliamentary election Tuesday did not hand him a clear victory. (VOA)

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