The goal for “A Brief History of the Future” wasn’t to ignore climate change or other seam rippers of the social fabric but, in classic Mr. Rogers style, to look to the helpers. “There’s a huge amount of focus in the news and storytelling in general on what could go horribly wrong,” Murdoch said. “What I really wanted to highlight was all the work that’s happening right now to make things go right.”

This was also Ritchie’s project. A data scientist by training, she began her career overwhelmed by climate pessimism. That feeling of hopelessness took a personal toll and a professional one, she believes, interfering with her ability to turn her mind toward solutions. Scientist colleagues who had once needed to push back against the public’s climate skepticism were now facing people who believed in a coming global catastrophe perhaps too much.

“There’s been a really rapid shift in the narrative, from almost complete denial to, Oh, it’s too late now, there’s nothing we can do, we should just stop trying,” Ritchie said.

Anger, fear and sorrow might motivate some people, Ritchie said. But they hadn’t motivated her. Her book, which emphasizes the progress that has already been made (clean energy) and the progress that might still be made (increased crop yields) is a deliberate alternative, participating in what she calls “impatient optimism.” Doomerism is not only a bummer, she argues, it’s also a cliché.

“The more negative slant, it’s already been done a million times,” she said.

But a bummer may be what we deserve. Climate activism has scored the occasional win — a reduced hole in the ozone layer, the comeback of the California condor. Still, any sustained inquiry into the challenges we face in the future, and even right now, as the world warms faster than predicted, offers a gloomier prospect.

To emphasize a cheerier one, examples tend to be cherry picked or gently massaged. A section in Ritchie’s book argues, correctly, that deaths from extreme weather events are fewer than they were in the past. But this section all but ignores the fact that extreme weather events are becoming more severe and more frequent, a trend that will continue even if harmful emissions are slowed. And it ignores any deaths from extreme heat, which Ritchie attributed, in conversation, to the insufficiency of the data.