Watchdog Q&A

Published — September 20, 2019

Q&A: Natalie Wolchover on a world without clouds


We’re continuing our series of Q&As with reporters who have uncovered powerful investigative stories. This week, we’re featuring Quanta’s Natalie Wolchover, who wrote a chilling article about a world without clouds. Wolchover detailed scientific experiments with sophisticated computer simulations that suggest a swiftly warming world will lead to cloud loss, swiftly pushing the Earth’s climate past a disastrous tipping point in as little as a century. 

How did you get the story? 

Scientist Tapio Schneider gave a talk at the American Physical Society in Los Angeles. His team had simulated Earth’s climate in a way that incorporated detailed cloud physics, and they had found a tipping point: When the carbon dioxide concentration increased in the simulated sky to roughly three times the current level, stratocumulus clouds suddenly broke up, triggering a huge and irreversible additional global temperature increase. Schneider and others had suspected the existence of this tipping point based on heuristic arguments, and because of unexplained, extreme temperature spikes in the paleoclimate record. But this study was the first evidence for it in climate simulations. I reported the story of the simulation and other evidence that clouds are the X-factor in Earth’s climate on and off over the next year as the study made its way through peer review.

What were the challenges of reporting and how did you navigate them? 

One challenge was that clouds are extraordinarily complicated, and they also have a very complex relationship with the rest of the Earth system. I had to dive deep into the physics, and into the long history of scientists struggling to understand how clouds work and how they’ll respond to and affect global warming. A virtually endless story sprang out from this one study, and in particular, I unexpectedly found myself interviewing a lot of paleoclimatologists and paleontologists who study Earth’s ancient past. 

Another challenge was that Schneider and team’s paper was embargoed for a lot of the time I spent reporting this story, so I had to learn as much as I could from experts about clouds, the uncertainties surrounding them and the major role they play in Earth’s climate mostly without talking to people about Schneider’s findings, which I was only able to discuss with experts in the final weeks before the paper’s publication. Some experts knew the broad strokes of the result earlier on while many didn’t, and some of my sources were rivals of Schneider’s doing similar work. I had to take care of all those relationships.

Lastly, this story is quite scary. It’s about the possibility of a sudden destabilization of the climate system; the prospects would not look good for big, needy mammals like us. Paradoxically, though, the story also offers hope, because it establishes a game-over scenario that’s very avoidable. If there’s really a stratocumulus cloud tipping point, humans would have to continue pumping CO2 into the sky unchecked for another century at least in order to reach it. Surely we’ll be forced to change our ways before then. 

Read the story and find Wolchover on Twitter.

Read more in Inside Public Integrity

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