President Obama speaks about the environment at the 20th annual Lake Tahoe Summit in Nevada.John Locher / AP

This is ‘Not Doomed Yet,’ The Atlantic’s newsletter about global warming. It lives here in the Science section; you can also get it in your inbox:

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This week’s most important piece of climate news is anticipatory: In the next few days (possibly late on Friday), China and the United States will likely join the Paris Agreement. The two countries account for about 39 percent of the world’s total carbon emissions. To enter into force, the Agreement requires countries constituting 55 percent of the world’s emissions to ratify it—so the two countries’ adoption of it get the UN document much closer to entering legal force.

Last week, California passed the most stringent carbon-emissions-reduction plan ever attempted in the United States. The state will attempt to cut its emissions by 40 percent by 2030. (The European Union is striving to make the same levels of cuts.) Brad Plumer of Vox looks at what that kind of jarring transition will take, and how the entire world will be watching how California fares.

And Barack Obama hinted on Friday that he will address climate change after his presidency ends.

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For the week beginning on August 21, 2016, the Mauna Loa Observatory measured average atmospheric carbon levels of 401.97 parts per million. A year ago for the same week, it recored carbon levels of 398.97 ppm. Ten years ago, it detected carbon levels at 379.88 ppm.

On Thursday night, Hurricane Hermine made landfall in the Florida panhandle, ending a record-breaking 10-year, 11-month hurricane drought in the state.

Some meteorologists are wondering whether “spaghetti plots”—those line-strewn maps that show where different models project a cyclone may hit—frighten people too much when they are shared on social media. “What were once backroom conversations among savvy meteorologists are now broadcast routinely on a public platform that acts more as interest group than it does social network.”

The Australian state of Victoria will extend a four-year moratorium on fracking into a permanent ban. Farmers who make up much of the state’s economy pushed for the restriction out of environmental concerns. It is the country’s first state-wide ban on fracking.

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Last week, the Working Group on the Anthropocene settled on 1950 as the rough start date for the new geological epoch, and I shared Paul Voosen’s story about it in this very newsletter. This week, Voosen posted the results of the group’s internal voting to Twitter. Most interesting, to me: 34 of 35 members thought the Anthropocene was “stratigraphically real,” only 30 members wanted to formalize it, and 28.3 members thought it should begin around 1950.

One member split their vote into thirds for “When should the Anthropocene begin?,” voting for “3,000 years ago,” “about 1950,” and “about 1964.”

And an interview with one member of the group, an ecologist, revealed discipline-level disagreement about where the line should be drawn: Stratigraphers tend to be on board with the concept, but geographers are more skeptical of it (because they’re so used to deep time) as are anthropologists (because they think humans have long shaped the Earth). “For a long time, science—especially Earth sciences—has viewed humans as insignificant. Overturning that would be a big deal!”

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In U.S. policy, the Iowa Utilities Board has approved the construction of a new onshore wind farm somewhere in the state. At 1,000 turbines, the farm will be the largest in the U.S.

Landsat 9, the next satellite in the U.S. government’s monumental 44-year project to photograph the changing planet, has secured key approval from NASA and remains on track for a late 2020 launch.

John Fleck, who has covered water rights in the American West for decades, says that a conservation mindset is taking hold around the Colorado River (and succeeding in saving much less water), but not around the Californian Central Valley. The doom-and-gloom attitude to water in the West should slow its roll, basically.

In 1856, an American named Eunice Foote discovered that carbon dioxide insulates energy from the sun’s rays better than other gases—in other words, the greenhouse effect—three years before the Irish physicist John Tyndall first published on the idea. Tyndall is commonly credited as the discoverer of the all-important phenomenon.

This is a surprisingly good late-night news segment about global warming: “‘Says who?’ is basically the Republican party’s official position on climate change.”

This week, the Anthropocene looked like: millions of bees, dead, at the entrance to their hives, after a South Carolina county sprayed the pesticide Naled from planes last Sunday morning

A few weeks ago, I posted an item that said that the theory that people populated the Americas by crossing the Bering Strait had been discredited. The story I posted now appears inaccurate:“A thorough reading of the study left the ‘Bering Strait Theory’ firmly intact. The new evidence in no way challenges it.” Rather, the study challenged how early Americans migrated from modern-day Alaska to the middle of the continent.

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