Newly reported comments by COP28 President Sultan Ahmed Al Jaber, which throw cold water on a potential commitment to phase out fossil fuels, were condemned by activists and observers at the U.N. climate summit in Dubai.

According to The Iran Project,Al Jaber’s remarks deepened controversy around the COP28 leader — who is also the chief executive officer of the Abu Dhabi National Oil Co. — and raised new questions over whether the conference will be able to unite behind a strong pledge targeting the elimination of fossil fuels. Just before the summit started, a BBC story alleged Al Jaber was ready to use COP meetings to discuss oil business, a claim he denies.

The comments "show how entrenched he is in fossil fuel fantasy and is clearly determined that this COP doesn’t do anything to harm the interests of the oil and gas industry,” said Mohamed Adow, director of the advocacy group Power Shift Africa. "These remarks are a wake up call to the world and negotiators at COP28 that they are not going to get any help from the COP presidency in delivering a strong outcome on a fossil fuel phase out.”

The controversy centered around an exchange Al Jaber had with former Irish President Mary Robinson, during a live online event Nov. 21, first reported by The Guardian and the Center for Climate Reporting. Pressed by Robinson to take a lead in "phasing out fossil fuel with a just transition,” Al Jaber said he was "not in anyway signing up to any discussion that is alarmist.”

"A phase down and a phase out of fossil fuel in my view is inevitable — it is essential — but we need to be real, serious and pragmatic about it,” Al Jaber said in the posted recording. "There is no science out there, or no scenario out there, that says that the phase out of fossil fuel is what’s going to achieve 1.5.”

Asked about the matter Sunday, a COP28 spokesperson stressed that Al Jaber remains focused on delivering a global stocktake (GST) plan "that will deliver maximum transition and minimal disruption for everyone in the world.”

"This story is just another attempt to undermine the presidency’s agenda, which has been clear and transparent and backed by tangible achievements by the COP president and his team,” the spokesperson said. "He has repeatedly communicated our position on fossil fuels and invited all parties to work together and come up with solutions that can achieve alignment, common ground and consensus.”

"We are excited with the progress we have made so far and for the delivery of an ambitious GST decision. Attempts to undermine this will not soften our resolve.”

The world could, in theory, limit warming to below 1.5 degrees Celcius even as it continues to use some fossil fuels combined with carbon capture technology that stop the greenhouse gas from entering the atmosphere. The International Energy Agency’s 1.5 C scenario, which requires reaching net zero carbon dioxide emissions by 2050, sees a rapid decline in the use of coal, oil and gas by mid-century, but fossil fuels are still being burned.

Still, the disclosure of Al Jaber’s remarks was rippling across the COP28 summit Sunday. One senior official from a small island state simply responded with an angry face emoji when asked about the report. Observers at the conference emphasized that rapidly curtailing greenhouse gas emissions is essential to limiting warming, with the IPCC in March projecting that carbon dioxide emissions must be reduced 48% by 2030 and 99% by 2050.

The issue is a major source of tension at COP28, as delegates grapple with what to say about the future of fossil fuels in response to the global stocktake assessment of the world’s lagging progress in cutting emissions under the Paris Agreement. Some oil-rich nations have balked at going beyond a commitment to "phase down” fossil fuels to pledge a "phase out” of them instead.

The world has a narrow chance — just 14% — of keeping global warming below 1.5 C even in the most optimistic scenario where existing net zero pledges are fulfilled, according to a November analysis by the U.N.’s environment program. Current emissions-cutting plans put the world on course for up to 2.9 C of global warming — and that’s assuming nations fulfill their commitments.

Romain Ioualalen, a global policy lead with Oil Change International, said Al Jaber’s "science-denying statements are alarming and raise deep concerns about the presidency’s capacity to lead the U.N. climate talks, at a time when leadership and a clear vision are most needed.”

They also raise the risk of the United Arab Emirates taking the blame for any breakdown in talks over possible fossil fuel phase down language, said Tom Evans, with the consultancy E3G.

"This now really amps up the pressure on Al Jaber,” Evans said. "If COP doesn’t strike a deal on eliminating fossil fuels, many countries will be to blame — but fingers will be pointing at the UAE.”