A Technological Piece of the Climate Change Puzzle
Or, how we can increase our chances of reversing anthropogenic climate change
We put 400 billion tons of carbon dioxide (CO2) into the atmosphere each year.
That CO2 makes it harder for the Earth to radiate heat back into space, decreases precipitation, increases the likelihood of extreme weather events, etc. You’ve heard it all before.
The current strategy is to lower carbon emissions so that the Earth doesn’t get warmer by another 1.5 degrees.
This won’t really do anything.
Newton’s First Law
Let’s say we cut all carbon emissions to zero by the end of 2030 (wishful thinking). That means we’ve switched to 100% renewable energy sources. The Earth still won’t get much cooler.
All of that carbon dioxide we’ve been putting out for the past 200 years is still in the atmosphere, warming the planet.
Cutting emissions to zero also means cutting out a large chunk of our society’s infrastructure. Take coal. It’s the literal worst, but so much of our society relies on it because it generates the power they need to function.
Because the inertia of the carbon cycle and human society is so great, we won’t see any benefits from dramatic efforts to decarbonize until late in the century.
The ball is too heavy and rolling too quickly to stop.
So what kind of solutions should we be focusing on?
A real climate change solution does not just mean lowering the amount of carbon dioxide we produce but also requires removing the carbon dioxide that’s already there in the atmosphere.
We need a combination of emissions reduction and CO2 removal, and we need it quickly before it’s too late.
Direct Air Capture
A popular carbon removal technology right now is direct air capture (DAC). DAC works by taking the ambient air and blowing it through a large processing plant until we’re able to isolate pure CO2 from it. We can then use that CO2 to create fuel, building materials, or even bottle it up for soda.
We’re currently at an atmospheric CO2 concentration of 410 ppm. That’s really dilute. This means today’s DAC plants need to spend a ton of energy to isolate that CO2 from the air. As a result, DAC is really expensive.
The best price right now is about $94/mT of CO2. Remember, we put out 400 billion tons of CO2 each year. That means if we want out society to be carbon neutral, not negative, we would need to spend trillions of dollars per year. And selling that CO2 wouldn’t bring in enough revenue to offset those costs either because there’s only a niche market for fire extinguishers and dry ice at best.
Right now, DAC is not considered a scalable way to remove carbon dioxide from our atmosphere.
The issue with DAC is that we’re using large amounts of energy and resources to pump air through a series of chemical reactions to take out pure CO2 from it that we can use.
But many of those steps are unnecessary.
Cyanobacteria are more often referred to as blue-green algae or just algae in general. They’re little photosynthetic bacteria. Like tiny plants. And just like regular plants, they use carbon dioxide for photosynthesis.
So what’s the idea, take the stream of pure CO2 gas from direct air capture and use it to feed the algae?
No, that’s horribly inefficient.
We can capture carbon dioxide from the air in the form of bicarbonate. Doing so allows us to remove 80% of the unnecessary steps from the direct air capture process.
But what’s so good about bicarbonate?
Cyanobacteria can utilize inorganic forms such as bicarbonate. Bicarbonate can be also be stored in solution, making it cheaper to use than pure CO2 gas to feed the cyanobacteria.
To recap, we can capture bicarbonate from the air (extremely cheaply) and use it to grow cyanobacteria.
BECCS is an acronym for Bio-Energy with Carbon Capture and Storage. It involves growing large amounts of crops to suck carbon dioxide from the air, burning them for electricity, and then making sure the resulting carbon dioxide doesn’t make it into the atmosphere (usually by capturing it in smokestacks and burying it deep underground).
BECCS is a controversial method of carbon dioxide removal because it requires very large amounts of land and water. Land and water that could be better used to grow actual food.
The interesting thing is that cyanobacteria don’t need a lot of land and water. They grow really fast. And they capture carbon much faster than trees.
I’m going to coin the term Cyanobacterial Bio-Energy with Carbon Capture and Storage (CBECCS). It’s like regular BECCS, but instead of planting and burning trees for electricity, we’re burning cyanobacteria for electricity.
Side note: Cyanobacteria can also be burned to form biochar, a soil amendment, and also can be used to produce biofuels and maybe feedstock.
Another recap — we can take carbon dioxide from the air in the form of bicarbonate (for much cheaper than just isolating it into a pure stream of CO2), and then use it to grow cyanobacteria. That cyanobacteria can then be used to generate electricity.
How would such a system work?
A combination of direct air capture and CBECCS.
I call it — Daybreak
We’ll try to use as little energy as possible in the direct air capture so that we can use it to grow cyanobacteria in photobioreactors. A photobioreactor is basically a fish tank without fish and only algae.
We’ve developed a completely passive air capture system that uses the power of the wind to direct airflow into our capture system. Once that air passes through our system, it’s officially free of carbon dioxide.
The carbon dioxide that we manage to capture (in the form of bicarbonate) is sent off through pipes to grow cyanobacteria. We’ve managed to find a way to fully automate the maintenance of our photobioreactors, so if everything goes according to plan, the entire Daybreak system would be fully automated.
And what would it cost?
That’s a conservative estimate.
We can even have a bunch of our fully-automated Daybreak systems all over the world, across areas with limited agricultural productivity, mostly deserts. Or, we can also place them near power plants if you so wish.