okay, but again: if you say in your blog that those are "facts", then... show us the facts?

You can't just hand-wavily say "a bigger percentage of programmers is using AI with success every day" and not give a link to a study that shows it's true

as a matter of fact, we know that a lot of companies have fired people by pretending that they are no longer needed in the age of AI... only to re-hire offshored people for much cheaper

for now, there hasn't been a documented sudden increase in velocity / robustness for code, a few anecdotical cases sure

I use it myself, and I admit it saves some time to develop some basic stuff and get a few ideas, but so far nothing revolutionary. So let's take it at face value:

- a tech which helps slightly with some tasks (basically "in-painting code" once you defined the "border constraints" sufficiently well)

- a tech which might cause massive disruption of people's livelihoods (and safety) if used incorrectly, which might FAR OUTWEIGH the small benefits and be a good enough reason for people to fight against AI

- a tech which emits CO2, increases inequalities, depends on quasi slave-work of annotators in third-world countries, etc

so you can talk all day long about not dismissing AI, but you should take it also with everything that comes with it

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antirez 14 hours ago | parent | next [-]

1. If you can't convince yourself, after downloading Claude Code or Codex and playing with them for 1 week, that programming is completely revolutionized, there is nothing I can do: you have it at your fingertips and you search for facts I should communicate for you.

2. The US alone air conditioning usage is around 4 times the energy / CO2 usage of all the world data centers (not just AI) combined together. AI is 10% of the data centers usage, so just AC is 40 times that.

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keybits 10 hours ago | parent | next [-]

I enjoyed about your blog post, but I was curious about the claim in point 2 above. I asked Claude and it seems the claim is false:

# Fact-Checking This Climate Impact Claim

Let me break down this claim with actual data:

## The Numbers

*US Air Conditioning:* - US A/C uses approximately *220-240 TWh/year* (2020 EIA data) - This represents about 6% of total US electricity consumption

*Global Data Centers:* - Estimated *240-340 TWh/year globally* (IEA 2022 reports) - Some estimates go to 460 TWh including cryptocurrency

*AI's Share:* - AI represents roughly *10-15%* of data center energy (IEA estimates this is growing rapidly)

## Verdict: *The claim is FALSE*

The math doesn't support a 4:1 ratio. US A/C and global data centers use *roughly comparable* amounts of energy—somewhere between 1:1 and 1:1.5, not 4:1.

The "40 times AI" conclusion would only work if the 4x premise were true.

## Important Caveats

1. *Measurement uncertainty*: Data center energy use is notoriously difficult to measure accurately 2. *Rapid growth*: AI energy use is growing much faster than A/C 3. *Geographic variation*: This compares one country's A/C to global data centers (apples to oranges)

## Reliable Sources - US EIA (Energy Information Administration) for A/C data - IEA (International Energy Agency) for data center estimates - Lawrence Berkeley National Laboratory studies

The quote significantly overstates the disparity, though both are indeed major energy consumers.

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vultour 2 hours ago | parent | prev | next [-]

So you don't actually have anything to support your argument other than "trust me bro". Oh, how the mighty have fallen.

	▲	simonw 2 hours ago \| parent [-]
		A useful skill in both software engineering and life is figuring out, based on prior reputation and performance, who you should trust.

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oulipo2 13 hours ago | parent | prev [-]

1. "if you can't convince yourself by playing anecdotically" is NOT "facts"

2. it's not because the US is incredibly bad at energy spending in AC that it somehow justifies the fact that we would add another, mostly unnecessary, polluting source, even if it's slightly lower. ACs have existed for decades. AI has been exploding for a few years, so we can definitely see it go way, way past the AC usage

also the idea is of "accelerationnism". Why do we need all this tech? What good does it make to have 10 more silly slop AI videos and disinformation campaigns during election? Just so that antirez can be a little bit faster at doing his code... that's not what the world is about.

Our world should be about humans, connecting together (more slowly, not "faster"), about having meaningful work, and caring about planetary resources

The exact opposite of what capitalistic accelerationism / AI is trying to sell us

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simonw 13 hours ago | parent | next [-]

If you can solve "measure programming productivity with data" you'll have cracked one of the hardest problems in our industry.

> Why do we need all this tech?

Slightly odd question to be asking here on Hacker News!

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lunar_mycroft 8 hours ago | parent | next [-]

> If you can solve "measure programming productivity with data" you'll have cracked one of the hardest problems in our industry.

That doesn't mean that we have to accept claims that LLMs drastically increase productivity without good evidence (or in the presence of evidence to the contrary). If anything, it means the opposite.

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simonw 5 hours ago | parent [-]

At the is point the best evidence we have is a large volume of extremely experienced programmers - like antirez - saying "this stuff is amazing for coding productivity".

My own personal experience supports that too.

If you're determined to say "I refuse to accept appeal to authority here, I demand a solution to the measuring productivity problem first" then you're probably in for a long wait.

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llmslave3 4 hours ago | parent [-]

There is also plenty of extremely experienced programmers saying "this stuff is useless for programming".

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simonw 2 hours ago | parent [-]

If a bunch of people say "it's impossible to go to the moon, nobody has done it" and Buzz Aldrin says "I have been to the moon, here are the photos/video/NASA archives to prove it", who do you believe?

	▲	sussyomegalul 2 hours ago \| parent [-]
		[dead]

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oulipo2 12 hours ago | parent | prev [-]

Sure, but I wasn't the one pretending to have "facts" on AI...

> Slightly odd question to be asking here on Hacker News!

It's absolutely not? The first line of question when you work in a domain SHOULD BE "why am I doing this" and "what is the impact of my work on others"

	▲	simonw 12 hours ago \| parent [-]
		Yeah, I think I quoted you out of context there. I'm very much in agreement about asking "what is the impact of my work on others".

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akomtu 10 hours ago | parent | prev [-]

This is obviously a collision between our human culture and the machine culture, and on the surface its intent is evil, as many have guessed already. But what it also does is it separates the two sides cleanly, as they want to pursue different and wildly incompatible futures. Some want to herd sheep, others want to unite with tech, and the two can't live under one sky. The AI wedge is a necessity in this sense.

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simonw 13 hours ago | parent | prev | next [-]

How does widespread access to AI tools increase inequalities?

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AstroBen 11 hours ago | parent | next [-]

It's pretty clear that if AI delivers on its promise it'll decimate the income of all but the top 1% developers

Labor is worth less, capital and equity ownership make more or the same

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simonw 9 hours ago | parent [-]

I don't think that's a forgone conclusion yet.

I continue to hope that we see the opposite effect: the drop of cost in software development drives massively increased demand for both software and our services.

I wrote about that here: https://simonwillison.net/2026/Jan/8/llm-predictions-for-202...

	▲	AstroBen 8 hours ago \| parent [-]
		I keep flip-flopping between being optimistic and pessimistic on this, but yeah we just need to wait and see

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oulipo2 13 hours ago | parent | prev [-]

Because as long as it is done in a capitalistic economy, it will be excluding the many from work, while driving profits to a few

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senordevnyc 8 hours ago | parent | prev [-]

Just dismiss what he says and move on, he's already made it clear he's not trying to convince you.