In a far corner of the temporary village housing the United Nations climate summit, the world’s largest cartel of fossil fuel producers plied skeptical young activists with chocolate and free pens.

It was Thursday afternoon. A continent away, in Vienna, the cartel’s members were voting to give the summit what amounts to another very small climate treat: at least a temporary reduction in oil and gas drilling. That’s the opposite of what President Biden, who has made climate policy a top priority during his administration, is delivering from the United States.

It was an opening-day irony for a COP28 summit that is already full of them, from its host country down to the so-called OPEC Pavilion in a building that is marked “Urbanisation & Indigenous Peoples” on the outside.

Tens of thousands of delegates are descending this month on Dubai in the United Arab Emirates, which is a member of the Organization of the Petroleum Exporting Countries and a major oil producer. Those delegates are celebrating an accelerating global transition toward low-emission sources of energy like wind and solar power. But expanding renewables is not enough to save the planet, scientists warn, so many delegates are demanding that the world rapidly phase out its use of fossil fuels.