[Ulrich2]

The core issue has nothing to do with Bitcoin: The environmental impact of "X" has to be priced into the product cost. That is a legal question at its core. I know that is easier said than done, but it is the only long term solution. CO2 certificates are one way to do it, and it already helps.

*X= Air Travel, Bitcoin, Cement... whatever creates large amount of CO2

And while we are at it: Overfishing is another huge tragedy of the commons that needs more attention.

https://en.wikipedia.org/wiki/Tragedy_of_the_commons

[hkt]

True, but the author is highlighting bitcoin as being a massive net contributor to CO2 emissions on a significant growth trend. It gets reported as "Bitcoin now uses more energy than $country" every once in a while now:

https://www.theguardian.com/technology/2017/nov/27/bitcoin-m... https://www.bbc.com/news/technology-56012952

That differentiates it from air travel, cement, etc. It is a worrying trend, even more so than the prosaic stuff.

Again, I don't disagree with the point you are making, but it seems remiss not to highlight the worst offenders.

[Ulrich2]

Fully agree. Interesting enough, global CO2 certificates would not affect Bitcoin at all (unlike air travel and cement). In the case of Bitcoin they would simply mean that the price per hash rate goes up for everyone, and therefore the difficulty is reduced.

So... if Bitcoin can push politics to make better, more air(!)-tight rules for CO2 certificates faster, then it would be clearly have a net benefit for the world.