Countries are being urged to get out of their comfort zones and work to reach agreement before the two-week COP28 United Nations climate summit ends.
"Let's please get this job done," COP28 President Sultan al-Jaber said on Friday, opening a plenary session as the summit entered its toughest phase of negotiations.
"I need you to step up and I need you to come out of your comfort zones."
With five days left before the conference's scheduled end on Tuesday, country ministers are joining the deliberations on Friday.
Still unresolved is how the almost 200 countries at COP28 will handle the thorny issue of fossil fuels, the main source of climate-warming emissions.
At least 80 countries are demanding a COP28 agreement that calls for an eventual end to fossil fuel use.
Such a position would be unprecedented, after three decades of UN climate summits that have never addressed the future role of fossil fuels head-on.
The Canadian environment minister was optimistic that a compromise could be reached.
"I'm confident we have to leave Dubai and COP28 with some language on fossil fuels," Canada's Steven Guilbeault said.
"Even if it's not as ambitious as some would want, it will still be an historic moment."
The UN climate agency's chief made an impassioned plea to countries, reminding them that the science behind the world's goal of holding warming to within 1.5C of pre-industrial temperatures was clear.
"From the planet's perspective, 1.5 is a tangible limit," said Simon Stiell, a Grenadian national who is executive secretary of the United Nations Framework Convention on Climate Change.
"It is not simply a choice.
"Pass 1.5 degrees and we're likely to irreversibly lose ice sheets" and 10 metres of sea level rise, the demise of coral reefs that sustain the world's fisheries, and temperatures so extreme that "two billion people will live in areas ... beyond the human limit and are a threat to life", he said.
Eastern European countries are also working to resolve an impasse over where to hold next year's COP29 summit after Russia said it would block any EU member as COP president.
As of Friday, the candidates included Azerbaijan, which offered to host the event.
Moldova and Serbia have also offered to take on the rotating presidency.
Australian Associated Press