Katowice, Poland (CNN) Hidden in the 133-page document agreed upon at the UN climate change talks was a compromise that many consider an infuriating distraction. The countries of the world agreed to welcome the fact that a scientific report on the state of global warming had been produced. But they failed to welcome its findings.

That seemingly small difference is massive in the hyper-subtle, hyper-polite world of climate diplomacy. So massive, in fact, that the bickering over the wording hung like a cloud over these negotiations. Almost 200 countries agreed -- barely -- to a "rulebook" governing the Paris Agreement on climate change, which is meant to help limit warming to 1.5 degrees Celsius.

Debate over whether to "welcome" the findings or simply "note" their existence flared up a week ago. The United States, Saudi Arabia, Kuwait and Russia -- among the leading producers of fossil fuels, which cause climate change -- stated publicly that they did not want to "welcome" the findings of a report the UN head had called an "ear-splitting wake-up call."

That report from the Intergovernmental Panel on Climate Change (IPCC) says carbon pollution must be cut about in half by 2030 and reach "net zero" by mid-century to avoid what could be described as disastrous climate change -- superstorms, floods and the like. Polish students walked out of school and into negotiations holding signs that underscored the urgency in this latest assessment of the science: "12 years left."

That urgency is new, but the basic science is not. Thirty years ago, a NASA scientist testified before Congress that the era of human-induced global warming had begun. In 1992, countries agreed to create the UN Framework Convention on Climate Change, which oversees talks on global warming now held at the end of each year.

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