Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

Everybody is talking about ChatGPT, the new machine-learning tool for answering questions. These giant computer models need a whole lot of computing power to run, so we were curious about just how much energy they use.

To find out more, had Will Malloy and Kolya Shields from our Possibly Team look into this. 

Will Malloy: Hi, Megan! 

Kolya Shields: Hello! 

Megan Hall: So does Chat GPT need a lot of energy to run? 

Will Malloy: To figure this out, we talked to Daniel Hershcovich

Daniel Hershcovich: I'm an assistant professor at the University of Copenhagen in the Department of Computer Science.

Kolya Shields: Daniel studies the sustainability of models like GPT-3, the algorithm behind Chat GPT. 

Will Malloy: He says, if you want to know the emissions associated with ChatGPT, you have to consider two things.

Kolya Shields: The first is training the model, or teaching it how to work. 

Megan Hall: How DOES it work?

Will Malloy: Basically, ChatGPT guesses what word comes next based on the words that came before.  

Kolya Shields: But for it to make good guesses, you have to teach it how humans speak. 

Will Malloy: And that process takes a long time…

Daniel Hershcovich: and it … takes … overall years of, GPU time … to train it… a massive amount of computation to create that.

Megan Hall: What’s GPU time? 

Kolya Shields: GPUs are the physical pieces of hardware that run all the calculations involved in this process. And it takes electricity to power all of the computers, which generates emissions.

Megan Hall: What’s the other thing you have to consider when it comes to how much energy ChatGPT uses?

Will Malloy: Well, then there’s actually running the thing…  Every time you ask ChatGPT a question, it takes some energy to give you an answer. 

Megan Hall: Okay, so it takes energy to train AND use ChatGPT. But overall, how big of an impact does that have? 

Kolya Shields: Turns out this is not an easy question to answer.

Will Malloy: The private companies that create these models, tend to be pretty secretive about exactly how much energy is used in these two processes. The creator of ChatGPT, OpenAI, isn’t sharing these values publically

Kolya Shields: BUT we can look at other similar models to give us a ballpark. Researchers estimate that the training for ChatGPT took about five hundred fifty thousand kilos of CO2. 

Will Malloy: That might sound like a lot, but in the world of carbon emissions, that isn’t a big deal. 

Megan Hall: What about the emissions associated with answering a question? Like, how many pounds of CO2 does it take for ChatGPT to tell me how to poach an egg?

Kolya Shields: Daniel says that his best estimate for ChatGPT comes from looking at publicly available data from a similar model. 

Daniel Hershcovich: For another language model called Bloom, …  CO2 emissions are equivalent to, 150 grams of CO2.

Megan Hall: 150 grams? That’s nothing!

Will Malloy: Well, that really depends how many questions we’re asking!

Kolya: But, the emissions from answering a question are mostly emissions caused by using electricity. 

Will Malloy: And the infrastructure that hosts ChatGPT is owned by Microsoft, which has already pledged to use carbon-free energy sources.

Kolya: Many other tech companies are also making an effort to get more of their energy from renewable sources, which reduces the emissions of not only ChatGPT but everything else on the internet, too! 

Megan Hall:  It sounds like I don’t need to worry about asking ChatGPT to help me poach that egg! 

Will Malloy: Yeah, there are plenty of things to worry about when it comes to AI, but as far as energy use, it’s not a big deal. 

Megan Hall: Now if we could prevent it from replacing people like podcast reporters…

Will Malloy: I think that’s a topic for a different show!

Megan Hall: That’s right! Thanks, Will and Kolya! 

That’s it for today. For more information, or to ask a question about the way your choices affect our planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

You can also follow us on Facebook and Twitter- at  “ask possibly” 

Possibly is a co-production of The Public’s Radio and Brown University’s Institute for Environment and Society and Brown’s Climate Solutions Initiative.