Much has been said in the last month about the use of electrical energy in crypto-mines. Reading several articles for and against, it is evident the lack of knowledge about the concept of efficiency, sustainability and environmentability.
When talking about these concepts, it should be compared with other models of equal proportion: just stating that it is not efficient, or that you believe that it uses electricity is not part of scientific concepts.

Considering that today is World Environment Day, I decided to put some concepts here and how the definitions would be coherently used:

First of all, it is worth remembering, within physics, that everything is energy and energy transformation. Useful part and not useful part (but result of the useful part process!)

- Efficiency: it is a relationship between the efficiency of a machine, the amount of energy that this machine actually uses, and what it transforms into non-useful energy. Nothing can yield greater than 100% and nothing less than 50% efficiency should be working.
Let's take a simple example, from day to day, the internal combustion engine car has maximum efficiency, in the best model, of 42%. This is what physics says that explains the operating cycle of this type of engine. That is, putting 1 dollar of fuel, 0.42 cents makes the car go and 58 cents comes out of the car exhaust, literally burned, adding to the noise of the car. The electric motor has an average efficiency of 97%, for comparison!

- Sustainability: is the ability of a product or system to keep operating, or producing, without depending on finite resources. Combined with the concept of efficiency, it allows for an analysis of how optimal a given process is that generates any product.
Unless you are a grower of organic products that depend exclusively on rainwater and without pesticides, on the land, as in the Middle Ages, any process on the face of the earth is not sustainable, because to some extent, everyone uses some kind of finite resource.
The question is not the word sustainability, but what a process is more or less aggressive to the environment, which is different from sustainability. Are solar panels more sustainable than coal-fired thermoelectric plants? It depends, because solar panels quickly lose efficiency, in addition to using batteries, necessarily, lead-acid or lithium. In addition, the maintenance of these solar panels requires water, soap, permanent cleaning, which normally does not count for the eco-borers...they simply "forget" about these energy costs.
Currently, after eliminating the initial environmental impacts, for comparison, only hydroelectric plants are sustainable, because they are designed to last 40 to 50 years and, once implemented, have very low maintenance.
Again to coal, replacing the material for biomass, or even nuclear, is the solar panel really sustainable due to the amount of maintenance and semiconductors involved? Even cadmium, a rare material, is used in the process. There is no solar panel in the world that maintains efficiency without constant maintenance and after 10 years, it's a fact!

- environmentability: ability of beings to live under the same biome. In this regard, man is champion of destruction. Nor can you comment on anything else. We have a duty to preserve so that our children have the land to live on, or move to Mars!
However, we have another problem: ecological balance. Well quoted smith, in the matrix, the only mammal on the planet that does not develop balance is man. But then we have another issue: the balance is only achieved if you let nature act, which means less medicine and more deaths. Fewer remedies and more natural processes. Spartans threw misshapen babies off the cliff, for example.
Cruelty? I don't know, but whoever shouts for the environment, sure, uses medicines, doctors, in short, all human technology. I myself, looking at it that way, should be dead within an hour of my life!
It must be kept to the environment, yes! It would be crazy to say something else, but along with the two other definitions, then, we must think about what to change in all the processes, including the one of madly making children!

Earth is finite! The Earth spacecraft, which is weighed down by the Sun's gravitational force, navigates, just like a spacecraft, with life support, gravity, motors and electromagnetic shields. The difference is that we can't change the ship's route.

So, just like a ship, we have finite resources on this trip.

The cryptocurrencies, as efficiency, have an 86% ratio between energy use and processing efficiency. Who puts it this way is nvidia, which puts the efficiency of their boards versus thermal dissipation.

So, from the point of view of aggression against nature, who attacks more: an internal combustion car or a mine of crypto coins?

To answer some Erlon Musk fans, do mines attack more or less than space rockets or send a car to mars?

Combating waste is the duty of every thinking mammal, biped, with a brain between its eyes.

The preservation of the environment too!

But hypocrisy and lack of technical clarity, combined with speculative discourse and hidden supra or intra-national interests are not.

Those who like to walk on all fours, instead of two legs, are left with the question: how much of their words affect the rest of the world more to the point of producing more social and, therefore, environmental impacts than crypto-mines?

In time, to think about it: crypto-mines are therefore 80 to 90% efficient.....the issue of paper money by countries is 55% efficient in the process as a whole. The manufacture and minting of precious metals such as silver and gold has an efficiency of 65%, of silicon, iron, aluminum and copper, in the order of 60%.

It's up to whoever decides, but do mines really use more energy, thinking about efficiency and sustainability, than everything else exposed?

Is Tesla's electric car, thinking about the entire production process, with lithium and silver batteries, with plastic, carbon alloys and aluminum, really efficient, sustainable and environmentally responsible? Same?

The electric motor is really efficient. But the abteria heats up a lot...which physically signals a terrifying loss of thermal energy!

You decide, dear readers!

Long live the crypto-currencies!