[triceratops]

> Data centers can run on air cooling just as good, but more expensive

"More expensive" means spending more on air conditioning. Ergo more electricity used, higher electricity demand, more natural gas burned and carbon emissions, higher consumer power prices. So a different kind of PR disaster.

[harddrivereque]

The difference in energy usage won't be noticeably higher for PR purposes. Of course, the difference comes at a price, cutting which is the main incentive for water usage.

[undersuit]

OK, so we need to include the effect of introducing a green house gas, water vapor, into the environment.