On Tuesday, as North America slept, delegates from around the world concluded the global climate conference in Dubai, when the chair — local oilman Sultan al-Jaber — quick-gaveled through an agreement that included a sentence calling for “transitioning away from fossil fuels in energy systems in a just, orderly, and equitable manner.”

That may not seem like much — it is, after all, the single most obvious thing one could possibly say about climate change, akin to: “In an effort to reduce my headache, I am transitioning away from hitting myself in the forehead with a hammer.”

And by itself it will accomplish nothing. As Samoa, speaking on behalf of the Small Island Nations, said a few minutes later, “We have come to the conclusion that the course correction that is needed has not been secured.”

But it is — and this is important — a tool for activists to use henceforth. The world’s nations have now publicly agreed that they need to transition off fossil fuels, and that sentence will hang over every discussion from now on — especially the discussions about any further expansion of fossil fuel energy. There may be barriers to shutting down operations (what the text of the agreement obliquely refers to as “national circumstances, pathways, and approaches.”) But surely, if the language means anything at all, it means no opening more new oil fields, no more new pipelines, and no more new liquefied natural gas (LNG) export terminals.

In fact, that last point — LNG export terminals — will almost certainly be the first real test of whether this agreement means anything. The American climate envoy John Kerry, who celebrated his eightieth birthday during the talks, could be forgiven for thinking of it as a crowning achievement. Though he acknowledged stronger language would have been nice, he said: “I think everybody here should be pleased that in a world of Ukraine and the Middle East war and all the other challenges of a planet that is foundering, this is a moment where multilateralism has actually come together and people have taken individual interests and attempted to define the common good. That is hard. That is the hardest thing in diplomacy, the hardest thing in politics.”

But Kerry’s job isn’t done. He needs to return home and convince the White House to pause the granting of new export licenses for the ongoing LNG buildout, a project so enormous that by itself it could produce more greenhouse gas emissions than all of Europe. If the White House agrees — and Dubai saw the release of a letter from 230 environmental organizations urging just such a pause — then we will know there was something real in all this endless talk.

And in that case, the bland sentence “transitioning away from fossil fuels in energy systems in a just, orderly, and equitable manner” would join at least two others in the long history of the climate talks as historically significant.

The first came in 1995, when the Intergovernmental Panel on Climate Change, in its second assessment report, said, “The balance of evidence suggests that there is a discernible human influence on global climate.” That bland sentence — bland for the same reason, because it also had to get past every government in the world — was the death knell for the argument that climate change wasn’t real; after it, no serious person (admittedly a category with many exceptions) could argue there was no need to do anything.

The second came in 2015, in the preamble to the Paris Agreement, when (at the urging of those same small island states) the text included a pledge to “substantially reduce global greenhouse gas emissions to hold global temperature increase to well below 2°C above pre-industrial levels and pursue efforts to limit it to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change.”

That recognition of 1.5 degrees changed the debate — but only because activists and scientists used it to demand that governments and businesses identify a “1.5 degree path,” which increased the seriousness of those plans. We’re not going to stay below 1.5 degrees — but that sentence may, in the end, knock half a degree off how much the planet warms.

If today’s sentence is to matter, it will need that same kind of activism, especially since the fossil fuel industry — the most well-represented “nation” at the talks — managed to lard the text with wiggle words. For instance, the agreement “recognizes that transitional fuels can play a role in facilitating the energy transition while ensuring energy security,” which the fracked gas industry is going to interpret as permission for them to go on pumping. We need to insist that the clear, plain meaning of the language is, the fossil fuel era is over. No more new digging and drilling.

What I’m trying to say is, today’s agreement is literally meaningless — and potentially meaningful. The diplomats are done now, so the rest of us are going to have to supply that meaning.