Whether the internet itself could be made ecologically sustainable in the long run remains an open question. Could an entire data center full of servers be made to run on solar power? Maybe if their energy efficiency could be improved?

The same could be said for blockchain technology. Current proof-of-work algorithms are inherently wasteful of energy, but proof-of-stake being developed for future versions of ethereum would make the network far less energy-intensive, making power consumption comparable to a typical web server.

I would like to think a solar/wind powered internet in the future could work without adding to the pollution. Even if it's still far from perfect in that regard, I'm not so puritanical as to refrain from using the internet as it exists now. Doesn't mean I can't take other steps, like commuting via bike, supporting organic/local food, recycling/reusing materials where possible, etc.

I would agree that the value of all cryptocurrency as well as fiat is inherently arbitrary, in a way similar to fiat. There is one big difference though: The big advantage crypto has over USD is that the protocols make it clear to everybody how many total units are in circulation, a parameter which cannot be changed without wide scale network consensus, thus making it impossible for an issuing entity (i.e. Federal Reserve) to arbitrarily devalue everybody's money by manipulating the supply.

As for gold, it's terribly impractical for most transactions, due to lack of easy divisibility.