Negotiators from almost 200 countries clinched a deal that broke new ground in the fight against climate change, but punted the hardest decisions into the future.​​

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While the U.K. leader said he was “immensely proud” of what had been achieved, he acknowledged that his joy was “tinged with disappointment” over successful efforts by some of the world’s largest emitters of greenhouse gases to water down the language in the agreement.

“We can lobby, we can cajole, we can encourage, but we cannot force sovereign nations to do what they do not wish to do,” Johnson said.

Language that called for the phase-out of coal was changed at the last minute to call for the phase-down of the fuel.

Still, that language would lead to the elimination of coal use, Johnson predicted.

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“It’s beyond question that Glasgow has sounded the death knell for coal power,” he said.

“Whether the language is phase down or phase out doesn’t seem to me, as a speaker of English, to make that much of a difference –- the direction of travel is pretty much the same,” Johnson said.