SCOTT DETROW, HOST:
Time now for our science news roundup from Short Wave, NPR's science podcast. And we have the show's two hosts here, Regina Barber and Emily Kwong. Hello.
REGINA BARBER, BYLINE: Hey.
EMILY KWONG, BYLINE: Hi, Scott.
DETROW: You have, as you do...
KWONG: Yeah.
DETROW: ...Brought us three stories from the world of science. What are they?
KWONG: A map of the AI energy crisis.
BARBER: And good news for an ocean moon of Saturn.
KWONG: And a new discovery about chameleons.
DETROW: Let's - since it seems the least joyous, let's start with AI computing.
(LAUGHTER)
KWONG: True.
DETROW: We talk a lot about AI these days, and there's a lot of concern about the power it's sucking up.
KWONG: Yeah. It - truly. A lot of AI computing relies on data centers. Data centers are these big buildings which gobble up gigawatts of energy, sometimes millions of gallons of water for cooling. And as tech companies try to make good on AI's potential, there is an energy crisis in the making.
DETROW: How so?
BARBER: Well, because the majority of these data centers are powered by fossil fuels. Tianqi Xiao is a Ph.D. candidate at Cornell University, and he says that if the tech industry and policymakers are not careful, the boom in AI will jeopardize our climate progress.
TIANQI XIAO: The monitoring will be much important in the next few years because before we know the whole picture, and it may already do something very bad for our environment.
KWONG: So this week, in the journal Nature Sustainability, Tianqi's team at Cornell published a state-by-state portrait of the environmental impact of AI. And this map took three years to make.
DETROW: Three years? What did it tell us? Was it worth the wait?
KWONG: Well, using data analytics and - ironically - some AI...
BARBER: (Laughter).
KWONG: ...The team determined that by 2030, at the rate of AI growth in the U.S. would put an additional 24- to 44 million metric tons of carbon dioxide into the atmosphere. And the team said it could use as much water as 6- to 10 million Americans do every year. All of this, the paper concludes, would put the tech industry's climate goals out of reach.
DETROW: Can you remind me what those initial goals were, or are?
BARBER: Yeah. So Google, Microsoft and Meta have all pledged to reach net-zero carbon emissions and to be water positive by 2030. Amazon has set their net-zero carbon deadline for 2040. But according to this paper, AI is putting all of those climate goals in peril. We reached out to these companies. Google didn't reply, and the others declined to comment.
DETROW: I mean, I'm hearing this and I'm feeling sad and discouraged.
BARBER: Yeah, me too.
(LAUGHTER)
KWONG: No. Never.
DETROW: Is that the right feeling?
KWONG: Never despair, Scott, ever, because a big part of this study is about solutions. The biggest takeaway is location. Study author Fengqi You says where you build a data center matters.
FENGQI YOU: If we build AI in the right place, on the clean power grid and with efficient cooling technology, it could really grow without blowing past climate and water limits.
KWONG: Fengqi wants data centers built in places with low water stress, that are already transitioning to clean energy. So spots in the Midwest and Wind Belt states like Texas, Montana, Nebraska and South Dakota are good candidates. And Big Tech has been scouting future data centers in some of these states.
DETROW: This still makes me anxious and worried.
BARBER: (Laughter) Yeah.
DETROW: And I think it's time to change the topic to an ocean moon...
KWONG: Yeah.
DETROW: ...Which I would much rather talk about (laughter).
BARBER: Yeah.
KWONG: What a pivot.
BARBER: Well, me too. Me too, Scott.
KWONG: Off Earth.
BARBER: I know you love space.
DETROW: I do.
BARBER: And you might remember that Saturn has 274 confirmed moons, right?
DETROW: Confirmed moons.
BARBER: Yeah. And one of those moons is Enceladus, and it's really intriguing to scientists looking for life elsewhere in the solar system because it has an ocean covering its entire surface that's locked under a thick layer of ice. And scientists say it could be a good potential spot for life.
GEORGINA MILES: It looks like all the right ingredients are there for it. All it needs is time.
BARBER: That's Georgina Miles with the Southwest Research Institute in Colorado. And the ingredients for life she's talking about are liquid water, chemicals like hydrogen, oxygen, nitrogen and carbon.
KWONG: And in a new paper in the journal Science Advances, she and her colleagues write about another important ingredient - a heating source.
DETROW: Which feels pretty important for life, huh?
KWONG: Yeah - turns out - because if the temperatures in the ocean fluctuate too much - are hot or too cold - that's not good for life. You want a stable heat-flow process. And overall, this study found that the heat flow seems to be pretty consistent on Enceladus.
BARBER: And that means that the ocean on Enceladus is very stable. It is now and probably has been for most of the moon's existence.
DETROW: Which I assume is another good ingredient for what we're talking about here.
KWONG: Yeah. It's promising because life takes a really long time to begin and develop. Here's Carly Howett, another author of the study and fellow planetary scientist.
CARLY HOWETT: We know that evolution is a slow process, but we're hopeful if it started on Enceladus, there might be something for us to see today.
DETROW: Something for us to see today - does that mean we're going there? Are we sending robots there? What's the situation?
KWONG: Not NASA, but...
DETROW: OK.
KWONG: ...The European Space Agency...
DETROW: Oh.
KWONG: ...May. Carly and Georgina are based in the U.K., and the European Space Agency is proposing a mission to Enceladus in the 2040s.
BARBER: But there is a NASA mission going to another promising moon of Saturn - Titan. It's set to launch in 2028, which is really soon. This moon has mountains of ice and methane lakes. The lander on this mission, Dragonfly, will do close-up measurements of Titan's surface.
DETROW: OK. That's interesting.
KWONG: Yeah.
DETROW: Can we also talk about chameleons? And can I make a request?
BARBER: Yeah.
DETROW: My 3-year-old daughter has recently started calling chameleons colorful lizards.
KWONG: They are.
BARBER: That's true.
DETROW: OK.
KWONG: They're part of a clade called Old World lizards.
BARBER: Yeah.
KWONG: And they are incredibly colorful and funky.
BARBER: Yeah. And, Scott, let me also start with this, like, stone-cold - like, this universal truth about these colorful lizards, these chameleons.
ED STANLEY: Every aspect of them is weird.
(LAUGHTER)
BARBER: This is Ed Stanley, an evolutionary biologist at the Florida Museum of Natural History.
STANLEY: They have fused fingers for grasping onto branches. They have all the color-change stuff. They have a ballistic tongue. Their body shape is absolutely bizarre, right?
BARBER: (Laughter).
STANLEY: Most lizards are short and wide.
DETROW: Yeah.
STANLEY: These ones are incredibly thin and tall.
KWONG: And there's another trait to add to the list. They've got really weird optic nerves, OK? So optic nerves - that's the bundle of nerve fibers that send information between the eyes and the brain in lizards - they're more straight, but in chameleons, those optic nerves are coiled.
DETROW: In Short Wave and ALL THINGS CONSIDERED, we love weirdos.
BARBER: Yeah.
DETROW: It's very true.
KWONG: Three of them are in this room.
DETROW: (Laughter).
BARBER: Yes (laughter).
DETROW: But in terms of our chameleon friends, why does all this weirdness matter?
BARBER: OK, so researchers suspect it could help chameleons move their eyes in those, like, strange, twisty ways. I'm sure you've seen this before, Scott, like, when one eye of a chameleon is, like, moving independently from the other.
DETROW: Oh, yeah.
BARBER: Like, maybe one is looking at an insect for lunch, and the other one's looking at another chameleon.
JUAN DAZA: Chameleons can even look backwards, so it's really bizarre for an animal.
DETROW: What?
KWONG: Right. OK, this is Juan Daza. He's one of the study authors. And he compared the coils of their optic nerve to those old landline telephone cords.
DETROW: Oh.
DAZA: We discovered at some point that if you made this cord twisted, you can have more range of movement.
KWONG: Like, remember the days when the phone would be in the kitchen and you could walk into the living room...
DETROW: So your mom couldn't hear you.
KWONG: ...'Cause the coil extended?
BARBER: (Laughter).
KWONG: Yeah, you didn't want that. Maybe the coil in the optic nerves of chameleons is what allows their eyes to go all catawampus like that.
DETROW: I mean, I'm kind of surprised this is all new information. We've all been loving chameleons for a long time.
KWONG: Yeah.
BARBER: Yeah. And scientists have dissected them. They've looked at chameleons. But that's probably why we didn't know this. So, like, dissections can damage the optic nerve. Researchers in this study used CT scans, which allowed them to get a 3D view of the chameleons' internal structures without destroying the optic nerve. They wrote about it this week in the journal Scientific Reports.
DETROW: That is Regina Barber and Emily Kwong, two weirdos...
BARBER: (Laughter).
KWONG: Proud.
DETROW: ...Who host NPR's science podcast...
KWONG: Yep.
DETROW: ...Short Wave. You can follow it on the NPR app or on your podcast platform of choice. Thank you to you both.
BARBER: Thank you.
KWONG: Bye, Scott.
DETROW: And a note that Google, Microsoft and Amazon are financial supporters of NPR.
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