[colordrops]

> 1) Surely we can come up with a less wasteful solution to this and

No one has found a solution yet that is as secure as proof of work, so this point is moot until then.

> 2) why should we assume that securing the block chain is a actually good use for the energy spent?

Who is this "we" you speak of? The energy is being paid for and the market demand demonstrates that it is a good use.

[MereInterest]

> Who is this "we" you speak of? The energy is being paid for and the market demand demonstrates that it is a good use.

This argument is nothing but an appeal to the majority. I could equivalently say that the existence of spam emails shows that spam emails are good for society. After all, spammers have paid for the electricity and bandwidth to send spam, and the market demand demonstrates that it is a good use.

Market demand is a useful tool for measuring the current state, not for predicting an ideal state.

[TeMPOraL]

> No one has found a solution yet that is as secure as proof of work, so this point is moot until then.

The point isn't moot. The point is that maybe we should stop pushing this tech forward until a less wasteful securing process can be developed.

> Who is this "we" you speak of?

This comes up often, and the answer is usually the same: that "we" are the people who consider the society they live in as something to contribute to and grow, and not as an exploitable resource to parasite on.

> The energy is being paid for and the market demand demonstrates that it is a good use.

Market demand only demonstrates that there are some people who are willing to pay money for this. Not that it's good or useful (see the spam example of sibling's comment). This is true especially if the thing is paying for itself.

[nodamage]

"We" refers to society that you wish to convince to adopt Bitcoin as a currency. As has already been mentioned, the mere fact that people are willing to spend electricity on mining does not inherently demonstrate that it is a good use of such electricity.

Again, I find this defense to be incredibly tautological:

"This approach to securing a distributed ledger sure seems to waste a lot of electricity."

"But it's not wasteful because it secures the ledger..."