by shawndrost | 2025-07-07 21:01:54+00:00
My statements about the recent history of declining US power sector emissions are pretty vanilla and I won't source them here, but they should be pretty easy to verify. What I'm asking you to take on faith (or to google) is that the positive trend was a mix of flat load growth and the energy transition (from coal to natgas, wind, and solar).

Load growth was flat 2005-2020, and now it's growing at circa 2%. Recent growth is almost all commercial and industrial, not residential [1]. There has been some manufacturing reshoring, etc, but the main driver is data centers [2].

"[D]ata centers consumed about 4.4% of total U.S. electricity in 2023 [and ~1.5% in 2014]." "[T]otal data center electricity usage climbed from 58 TWh in 2014 to 176 TWh in 2023 and estimates an increase between 325 to 580 TWh by 2028 [which would be circa 20% YOY growth]." [3]

Total US power use in 2023 was ~4000TWh. Compute power demand was at 4.4% of that and has been growing at ~20% YOY. (McKinsey forecasts 23% YOY growth and 2025 data center capex is growing 30%[4] but let's be conservative.) If 20% holds from 2023 through 2030 data center power demand will be at ~630TWh (16% of the size of the 2023 grid). If it holds through 2040 it will be at ~4000TWh (100% of the size of the 2023 grid). (No citations here, this paragraph is just analysis, and 630/4000 TWh are just 176*1.2^7/17. However these numbers are similar to the forecasts in [2] and [3].)

New data centers are more often powered by natural gas (and less by wind/solar) vs the grid at large, and will be true for the foreseeable future. I don't have a definitive citation for this but it's obvious to anyone close to this industry (as I am) and you can dig up any number of confirming citations about specific data center stories or utility IRPs (integrated resource plans). One concrete fact supporting this narrative is that gas turbines are sold out for the next ~6 years, which I don't believe has happened before in this century. Gas is on an absolute tear.

(Zero-carbon data centers that you read about, like Three Mile Island or next-gen geothermal, are specifically manufactured to disrupt the powered-by-gas narrative. They are about as common as data centers built in a way that revives coal plants; that is, they are a real but small phenomenon.)

So, that is the story. A) Power sector emissions were in decline, because of flat load growth and the replacement of coal with wind, solar, and natgas. B) This isn't true anymore; the grid is expanding quickly again, AI is the main culprit. C) At least for now, load growth is happening in a way that is dirtier than today's grid. C) If you believe that AI is going to continue to grow for 5-15 years like it is now, you also think that AI is (and especially, will be) a major driver of US greenhouse gas emissions.

And to add an anecdotal rebuttal to your earlier comment: sure, inference is just a few google searches worth of power. But now google searches have inference, so they are a few more times more power-hungry than they used to be. And when I code, I use way more inference than the number of times I used to google. And remember that when we say "inference", we are talking about last-gen LLMs; reasoning models (which are, as of a few months ago, the default in chatbots) are a chain of inferences which can be arbitrarily long. The current status quo is much more worrisome than your quip, and the problem compounds quickly if you extrapolate at all.

We have discovered a new and outrageously popular way to use compute, we built $455B worth of power-hungry data centers last year [4], and it is having (and will have) a huge effect on greenhouse gas emissions.

[1] https://www.eia.gov/todayinenergy/detail.php?id=65264 [2] https://www.utilitydive.com/news/load-growth-challenges-supp... [3] https://www.energy.gov/articles/doe-releases-new-report-eval... [4] https://www.ciodive.com/news/data-center-ai-cloud-infrastruc...