Hey Karen! First of all I want to massively thank you for replying to this. I realize this was a lot of very specific criticism and that you’re very busy. Also thank you for taking the time to find and email me your water source.

First and most importantly, the source you sent me actually strongly confirms my criticism, and unfortunately this does mean your measurement of the data center’s proportion is 1000x too high. My criticism specifically is that you misread cubic meters as liters, and this is making your estimate of how much water the city uses 1000x lower than it should actually be (and thus making the data center seem like it’s using 1000x as much water as the city).

Here's a link to the key part of what I see in the document you sent: drive.google.com/file/d…

Importantly, these numbers don’t have units. I see you requested the measurement in liters, but your source just says these are the “amounts.”

There are 4 ways we can tell that these numbers are measuring cubic meters and not liters:

-In the document I’m relying on, Cerrillos is about 10% of the water demand of the municipality, and the total water demand of the municipality is 54,148,639 m³. So 10% of that gets us to around 5,400,000 m^3, basically the exact same number as the one your source gave without units. This seems to conclusively show that the numbers you sent are measuring meters cubed, NOT liters, and your estimate is for the city is 1000x as low as it should be. These numbers are just way way too close to be a coincidence. (media.smapa.cl/media/do…)

-In every document this municipality produces on water I can find, they always measure in meters cubed. (transparenciamaipu.cl/w…)

-My argument stands that 5 million liters for a city of 88 thousand people is so little water that people wouldn’t even have enough to drink every day. There are no cities where each individual person only uses 0.12 L per day. During the Zero Day Capetown water emergency in 2018, the government limited citizens to 50 L per person per day. So even in one of the most extreme water scarcity scenarios that has ever happened, people are still using 500x as much water as your number. No way it's correct. en.wikipedia.org/wiki/C…

-This number also brings the water use per person basically perfectly in line with Chile’s average water per person. 5,000,000 M^3 converted to liters, divided by 365, and then divided by 88000 people gets us to 155 L per person, basically exactly in line with Chile's average of 170-180 L per person. So multiplying by 1000 is the only possible way to keep your number in the same order of magnitude as the water average Chileans use. (dialogue.earth/en/water….)

I’m completely confident that this shows you made a mistake and that you need to correct this section of your book. Your estimate is 1000x too high.

I have to say I’m still extremely worried that readers are coming away from this section with a lot of massive misunderstandings of basic questions of water use that don’t reduce to philosophical disagreements, that would really be helped by some corrections in the book itself.

Going down the list:

-It’s not the case that Making AI Less Thirsty predicted that AI would consume that much water. It might be that we have a philosophical disagreement on how to define the word consume, where you use it more expansively to mean temporarily diverting water from a source before putting it back, but this clearly doesn’t fit everyday people’s understanding of the word. If I put a water wheel in a river that raised water up and then dropped it back in a few seconds later, I think most people would be confused if I said that the wheel were “consuming” the water. I would really appreciate some kind of correction on the wording there, and that only 3% of those 1.1-1.7 trillion gallons is drinkable water. I’m confident that if any reader came away from your paragraph, and I said “90% of that water is returned unaffected to the source, and only 3% is drinkable water” the reader would be very surprised. Even if this is a philosophical difference, surely you agree that this surprise would happen and is a sign that the average reader is coming away with a wildly off base understanding of how much water AI is actually predicted to use by the paper you cite? Your language around data centers “sucking up” the water in your Atlantic piece also seems like it can’t possibly mean “they temporarily use and then return water.” It’s really important to me that fellow environmentalists have a clear picture of where the largest water issues in society are, and I’m worried this section can seriously lead them astray.

-No data centers anywhere use their maximum permitted water allowance regularly. Your calculation implies this one would, even though on average it seems like data centers only use about 20% of the permitted amount. Again, this isn’t a philosophical difference, because your readers are left to infer that the data center would actually use this much water.

I’d be really eager to get a response.