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These small words could make or break the global climate summit

Krisztian Bocsi/Bloomberg/Getty Images

The thorniest issue at the global climate summit in Dubai is clear: Fossil fuels. More precisely, the role they should play in our rapidly warming future.

As negotiators thrash out the terms of core agreements that will emerge from COP28, the big question is whether countries will ultimately agree to a phase-out of oil, gas and coal, a phase-down — or neither.

The difference between phase-out and phase-down sounds like semantics, but the ability of the world to hold back catastrophic climate change may hinge on it.

While concrete definitions are hard to pin down, a phase-out generally means the world will at some point stop burning oil, gas and coal altogether and bring levels of planet-heating pollution down to zero.

A phase-down, however, leaves the door open for countries to continue burning fossil fuels.

It “can mean anything where the future level (of fossil fuel burning) is lower than today’s,” said Joeri Rogelj, a climate professor at Imperial College London. The word “implies a level of ambition that is less clear, and also less ambitious, than a phase-out,” he told CNN.

Tensions around the terms were heightened this week in the wake of newly surfaced comments made by COP28 President Sultan Al Jaber, in which he claimed there was “no science” saying a phase-out of fossil fuels is necessary to restrict global warming to 1.5 degrees Celsius above pre-industrial levels.

He told reporters Monday that his comments were misinterpreted, and a fossil fuel phase-out was “inevitable” and “essential,” but the comments sent shockwaves through the summit.

More than 100 countries have pushed for the phase-out language, and dozens of scientists signed an open letter Wednesday stating that “the link between climate science and fossil fuel phase out is unequivocal.”

So, if the agreement lands on phase down, will that make it even harder to restrict global warming to 1.5 degrees Celsius?

“In isolation, yes,” Rogelj said, “but words and context matter and it’s not black or white.” A text that agreed on a phase-down of all fossil fuels by 2050, for example, with specific targets for the decline of coal, oil and gas could be very positive, he said.

The devil will be in the detail, and even if the more ambitious phase down terminology is agreed, there’s another important word to account for: “unabated.”

The EU and the US, for example, have both called for a phase-out of “unabated fossil fuels.” This would mean an end to burning oil, gas or coal without capturing the planet-heating pollution before it escapes into the atmosphere, where it contributes to global warming.

The “abatement” refers to carbon capture and removal — a set of techniques that are being developed to remove carbon pollution from the air and to capture what’s being produced from power plants and other polluting facilities, then storing it or reusing it. Many scientists have expressed concern that carbon capture is expensive, unproven at scale and a distraction from policies to cut fossil fuel use.

The world has taken so long to cut emissions that scientific bodies such as the Intergovernmental Panel on Climate Change say a limited amount of carbon capture will be needed. It is likely to be required for certain sectors, such as agriculture and aviation, for which “zero emissions does not seem possible in the coming decades,” said Pierre Friedlingstein, a climate professor at the University of Exeter in the UK.

The question is, how much would be used and how effective would it need to be: If a fossil fuel plant captured 51% of its emissions, for example, would that be considered abatement?

The word “is meaningless without clear quality standards,” said Lisa Fischer, a program lead at climate think tank E3G.

The summit’s final agreement is expected around December 12, and experts are pushing for language to be precise, given the stakes.

Clarity is essential, Fischer said. “Ambiguity now doesn’t help anyone but the fossil fuel industry.”

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