The energy use claims are questionable, but I at least get where they're coming from. The water use is the confusing part. Who looks at a server rack and goes ‘darn, look at how water intensive this is’? People use water as a coolant in large part because it's really hard to boil, plus it's typically cheap because it regularly gets delivered to your front door for free.

As to actual numbers, they're not that hard to crunch, but we have a few good sources that have done so for us.

Simple first-principles estimate: https://epoch.ai/gradient-updates/how-much-energy-does-chatg...

Google report: https://arxiv.org/abs/2508.15734

Altman claim inside a blog post: https://blog.samaltman.com/the-gentle-singularity