Just adding a square kilometre of parking lots raises the surrounding temperatures measurably, so I don't see how building a datacenter that size is going to have less impact
I realize the wording in my comment was a little ambiguous, but don't worry, that's in addition to my files in general. (Restic, Backblaze B2, memorized passwords/keys, regular integrity checks of remote data.)
After all, even with godlike storage-media on my keychain, it would still be susceptible to a mugger or falling down a deep hole. Until that happens, it provides redundancy and convenience, provided I can bring it to a trustworthy computer.
Or just ask if you might want to do something productive while you wait for a train or sit in a taxi? Better than doom scrolling. Maybe you're working on a fun side project.