> The only issue is convincing all those miners to go against their economic interest. The minute someone comes up with a 51% attack that actually is in the fi

> The only issue is convincing all those miners to go against their economic interest. The minute someone comes up with a 51% attack that actually is in the financial interests of the miners, this becomes easy. This is likely why it will be so difficult to ever move Bitcoin to a more economically friendly system: The miners will see any attempts coming and use their power to manipulate the system in the direction that benefits continued mining instead of more eco-friendly forks. Bitcoin mining is a cash cow for a relatively small number of big players who have heavily invested in mining gear. They have no interest in letting this golden goose slip away.