MIT engineers make converting CO2 into useful products more practical

To remove the co2 we put into the atmosphere will always take way more energy than we got out of putting it into the atmosphere in the first place. That is just thermodynamics.

To remove all the co2 we put into the atmosphere would take more energy than we extracted from fossil fuels since the industrial revolution. And all that energy would, of course, have to be produced in an absolutely carbon-free manner.

So this is and will remain an entirely impractical method of combatting global warming. MIT engineers know this. The people who funded this research know this. Why are they doing this?

Positive interpretation: Because they hope to find a method of doing it, that does not require too much energy, so that that method can be done using renewables.

Negative interpretation: Because of look/appearances/prestige.

From the article : "The work was supported by Shell, through the MIT Energy Initiative." Would it only exist to make people believe we can burn fossil fuels since a solution is around the corner ?

Think of carbon in the atmosphere as a debt.

Obviously you cannot effectively pay off debt using the money that you borrowed: that just leaves you with a net loss of the interest/friction/inefficiency.

But if you can earn enough money to pay down the debt (which naturally also requires weaning off of the deficit spending in the first place) via other means such as renewable energy sources in great excess to the quantity of fossil fuel energy we have produced thus far, then figuring out how to pay down the debt as efficiently as possible as soon as possible absolutely makes sense.

Portable, energy dense fuel is incredibly more valuable than grid electricity - especially back when most of it was burned, before modern battery technology.

It is not obvious to me that the net thermodynamics are important here. The only thing that matters is the real world cost vs benefits. Carbon free energy is extremely cheap now, and getting rapidly cheaper, yet still not very portable.

The problem is how fast we are adding "debt". The earth is naturally slightly CO2 negative without human intervention. However currently there are thousands of years to make up for every year of CO2 we are adding. I say thousands, but I haven't been able to figure out a true number, so thousands is conservative, it could be in the hundreds of thousands.

We are kind of relying on the oceans to soak up excess atmospheric co2 at the risk of acidifying the oceans too much. It’s one of those things where it’s such a huge problem and for which we have no solution.

// If you can earn enough money to pay down the debt //

If we could divert enough energy to do that, we could have not put it into the air in the first place!!

We are talking about an absolutely ginormous amount of energy. It would take more energy than the human race has used since the industrial revolution to "pay down the debt" (to use your metaphor).

// It is not obvious to me that the net thermodynamics are important here. //

You are obviously not a golfer.

// That does not require too much energy //

It inherently takes more energy to "unburn" co2 than you got from burning it in the first place. We burn co2-producing fuels just because of this fact--they give us tons of energy!

But it would take yet more tons of energy to unburn it. That is just thermodynamics. There is no magic science wand to wave here.