Oct 19 JDN 2460968

The conventional wisdom is that AI is consuming a huge amount of electricity and water for very little benefit, but when I delved a bit deeper into the data, the results came out a lot more ambiguous. I still agree with the “very little benefit” part, but the energy costs of AI may not actually be as high as many people believe.

So how much energy does AI really use?

This article in MIT Technology Reviewestimates that by 2028, AI will account for 50% of data center usage and 6% of all US energy. But two things strike me about that:

1. This is a forecast. It’s not what’s currently happening.
2. 6% of all US energy doesn’t really sound that high, actually.

Note that transportation accounts for 37% of US energy consumed. Clearly we need to bring that down; but it seems odd to panic about a forecast of something that uses one-sixth of that.

Currently, AI is only 14% of data center energy usage. That forecast has it rising to 50%. Could that happen? Sure. But it hasn’t happened yet. Data centers are being rapidly expanded, but that’s not just for AI; it’s for everything the Internet does, as more and more people get access to the Internet and use it for more and more demanding tasks (like cloud computing and video streaming).

Indeed, a lot of the worry really seems to be related to forecasts. Here’s an even more extreme forecast suggesting that AI will account for 21% of global energy usage by 2030. What’s that based on? I have no idea; they don’t say. The article just basically says it “could happen”; okay, sure, a lot of things could happen. And I feel like this sort of forecast comes from the same wide-eyed people who say that the Singularity is imminent and AI will soon bring us to a glorious utopia. (And hey, if it did, that would obviously be worth 21% of global energy usage!)

Even more striking to me is the fact that a lot of other uses of data centers are clearly much more demanding. YouTube uses about 50 times as much energy as ChatGPT; yet nobody seems to be panicking that YouTube is an environmental disaster.

What is a genuine problem is that data centers have strong economies of scale, and so it’s advantageous to build a few very large ones instead of a lot of small ones; and when you build a large data center in a small town it puts a lot of strain on the local energy grid. But that’s not the same thing as saying that data centers in general are wastes of energy; on the contrary, they’re the backbone of the Internet and we all use them almost constantly every day. We should be working on ways to make sure that small towns aren’t harmed by building data centers near them; but we shouldn’t stop building data centers.

What about water usage?

Well, here’s an article estimating that training ChatGPT-3 evaporated hundreds of thousands of liters of fresh water. Once again I have a few notes about that:

1. Evaporating water is just about the best thing you could do to it aside from leaving it there. It’s much better than polluting it (which is what most water usage does); it’s not even close. That water will simply rain back down later.
2. Total water usage in the US is estimated at over 300 billion gallons (1.1 trillion liters) per day. Most of that is due to power generation and irrigation. (The best way to save water as a consumer? Become vegetarian—then you’re getting a lot more calories per irrigated acre.)
3. A typical US household uses about 100 gallons (380 liters) of water per person per day.

So this means that training ChatGPT-3 cost about 4 seconds of US water consumption, or the same as what a single small town uses each day. Once again, that doesn’t seem like something worth panicking over.

A lot of this seems to be that people hear big-sounding numbers and don’t really have the necessary perspective on those numbers. Of course any service that is used by millions of people is going to consume what sounds like a lot of electricity. But in terms of usage per person, or compared to other services with similar reach, AI really doesn’t seem to be uniquely demanding.

This is not to let AI off the hook.

I still agree that the benefits of AI have so far been small, and the risks—both in the relatively short term, of disrupting our economy and causing unemployment, and in the long term, even endangering human civilization itself—are large. I would in fact support an international ban on all for-profit and military research and development of AI; a technology this powerful should be under the control of academic institutions and civilian governments, not corporations.

But I don’t think we need to worry too much about the environmental impact of AI just yet. If we clean up our energy grid (which has just gotten much easier thanks to cheap renewables) and transportation systems, the additional power draw from data centers really won’t be such a big problem.