If electricity consumption is the problem, why miners do not focus on renewables?
I think some miners don't use renewable resources (like solar panel) because they don't have so much money to buy for it and maintain it in their way. And also they don't have supply to be able to reproduce it in their own. Likewise, using non-renewable resources is easy to do because you don't have to maintain it. All have to buy is the equipment needed to produce electricity.
But if the use of bitcoin mining from renewable sources increases, does that threaten the future of energy? "We will not have enough energy for future generations"
Why do you think we will not have enough energy if they will used renewable resources?
It is a good thing to use it because it can be used repeatedly and can be replaced naturally. If companies will use solar energy or some kind of energy from nature. It will really help our environment to not consume so much power from non-renewable resources.