This Could End the Climate Crisis
… And even help Big Oil feel better in the process.
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The global temperatures keep increasing as we keep dumping more and more CO2 into the atmosphere every year. The Paris Agreement is “too little, too late”. It is time to think about carbon capture, but this is not going to be easy. I would like to explain the problems associated with it, but also to introduce a little-known solution that leverages existing infrastructure. I’d like to talk about the solution’s side effects — and the fact that a surprising amount of them would be positive, for everybody. Even for Big Oil.
The Problem(s)
The CO2 we keep releasing into the atmosphere is a problem, and most of the world recognizes it as such, which is why the Paris Agreement exists. However, not only are we failing to meet the agreement’s goals, the goals themselves are only half of what is necessary to slow climate change, according to Sir Robert Watson. Last week, Elon Musk has announced a 100 million dollar prize for a carbon capture technology on Twitter.
However, this is easier said than done. We have three technical problems:
1. Energy
The main reason we put the CO2 into the atmosphere is this: combining carbon with oxygen — aka burning stuff — gives us a lot of energy. Converting CO2 into anything useful would require us to strip the O2 back off the carbon, which would require us to put all of this energy back, plus some — there is no free lunch. This energy has to come from somewhere. Unfortunately, most of our energy still comes from burning carbon. Because of this, and the low efficiency of coal (35%), oil (37%) and gas (45%) generators, you would currently put more CO2 into the air generating the energy necessary for the capture, than you would capture in your fuel.
2. Storage
All the methods that don’t require stripping off the O2, don’t really do anything useful with the CO2, except storing it. But storing it is not an easy proposition — it is a gas. It is heavier than air. It is colorless and odor-less. It mixes with air. It also readily displaces air, and when it does, it kills people. Wherever you store it, it better be really airtight — pretty much forever. This method of sequestering it is an ugly, temporary hack at best. Also, we need to store a total of 2 trillion metric tons of CO2 to get back to pre-industrial levels. For comparison: 1 kilo of CO2 at atmospheric pressure would fill about 2 bathtubs. Or, pressurized, a bit more than two sodastream bottles. There is 1000 kilo to a metric ton. 4000 trillion is … a lot of bathtubs. Yes, 12000 old off-shore oil wells might do it — and might provide some redemption to the Big Oil in the process. However, as we have learned from numerous off-shore oil leaks, they will also create regional carbon bubble-baths in the ocean — a process that will not only put the CO2 from that well back into the atmosphere, but also kill the marine life around it.
If you do, somehow, capture the CO2 into something useful without liberating more of it, eventually the useful thing will get used. then discarded. Which frees the CO2, again. Back to square one.
3. Infrastructure
The sheer moving of the carbon molecules by technical means to capture it would require a comparable amount of infrastructure that we use to produce the CO2. Unfortunately, the infrastructure we use to put it there is literally all of our world-wide industry and transportation combined. Here is a good thread on the topic:
Of course the car is more than just its motor, and a power-plant is more than its generator, but the scale is the same, to an order or two of magnitude. Let’s say 1/100th of our machinery is devoted just to burning stuff. Now imagine building 1/100ths of the entire world’s infrastructure to capture it back. Hint: there are currently 1.4 billion cars in the world, and we build 92 million new cars, ie 92 million combustion motors, per year. Just cars.
So even if we re-tool the entire car manufacturing of the world to build as-of-yet-undesigned carbon capturing machines instead of ICE motors, it would take us roughly 14 years to compensate just for the existing cars alone. At this point we are not capturing any new CO2. We are not offsetting the carbon from the industry, or power generation, or agriculture. We are not even building new cars. Oh, and we haven’t paid for any of it yet. So there is a the non-technical problem Nr. 4:
4. Capital
Nobody wants to pay for it. Heck, nobody wants to even pay for CO2 emission reduction. This is why it took us 30 years since Climate Change became news to even start moving. And it is going to be Expensive: want to re-tool the auto industry to produce carbon-capturing machines, as mentioned above? Compensating the car industry for the loss of profits would cost us a trillion dollars per year. And we haven’t even started talking about the energy yet. Or any other sector than transportation.
To summarize:
- We need a lot of energy from sources that don’t produce new CO2
- We need a way to safely store the carbon
- We need to build a lot of infrastructure
- We need a lot of money
After 30 years of trying to deal with this issue world-wide, it should be pretty obvious by now that we are simply not going to do it the traditional way. All agreements, activism and good wishes aside, just paying for the infrastructure will be a challenge. And so will be building it.
Wouldn’t it be great if we had a solution that
- Used energy that we don’t have to produce
- Stored the carbon in a form that will stay stable for long times and will not erupt catastrophically
- Re-used existing, obsolete infrastructure — or even built the infrastructure by itself
- Had the largest possible impact with the least possible investment
Sounds like science fiction, right?
Maybe not. As Archimedes once said, “Give me a lever long enough, and I will move the world.” Turns out, we might have already found the lever.
The Solution Puzzle
Trees: Close, but no Cigar
In the replies to Elon Musk’s announcement, there were a lot of mentions of trees. Trees are great:
- they capture CO2
- they store it as lignin — the stuff that the trunk is made out of, something that is rather difficult for microbes to digest and release back as CO2
- they are almost free, because they grow almost by themselves.
The problem is the “almost”. The Sahara greening project showed us that greening projects require a lot of maintenance. 80% of trees planted there have died. Only traditional land management techniques — management, ie constant tending by the farmers — have succeeded in preserving the rest. But it gets worse: it turns out, the sand that gets blown away in the Sahel serves to fertilize the Amazon, among other things. If we green the Sahara desert, the stream of dust will stop. The plants in the Amazon will stop getting enough nutrients. It will stop serving as a carbon sink. And the Amazon is not the only carbon sink that relies on it — but more on that later. In addition, it will decrease Sahel’s albedo —its reflectivity. Green plants (and solar panels) absorb more sunlight than the sand. While, counter-intuitively, this will probably make the Sahel wetter, it will, at the same time, trap more heat from the sun, and increase the global warming — the very effect we are trying to avoid.
Don’t get me wrong: stopping the spread of the Sahel is a fantastic idea. We should also, by all means, green it (but be prepared to deal with the consequences.) Forests are great, and we need more trees, and more forests. But they are not going to magically solve our CO2 problem, or our global warming problem, because of the required scale.
Trees are slow: it takes half an acre of trees to capture one car’s annual exhaust. Remember when we said we are building 92 million new cars per year? Yeah. That is 186 thousand square kilometers (72 thousand square miles) of new forest per year. One Nebraska full of trees every year. The whole of Texas in a bit over three years. To offset just the existing cars you would have to cover roughly half the US in trees. And we have not even touched agriculture or industry yet. You all really like trees, right?
There is another problem with land-based plants: I mentioned earlier that the Amazon rain forest relies on the Sahel for fertilizer. Contrary to popular belief, plants don’t grow “just” on sunlight, water and air: the fertilizer you put into your pot is not just “a little extra boost”: it contains nutrients without which no life can live and function. The best-known ones are nitrogen and phosphorus: every single piece of DNA, the information storage of the cell, contains both of those chemicals. Proteins, parts of all the machinery in our cells, require nitrogen as well. Many enzymes require other chemicals like potassium, magnesium or iron. It is simply not possible for life, as we know it, to exist without them, because they are what life is built out of.
Incidentally, this is also the reason why the “Global Greening” hypothesis — also known as “CO2 is just plant food”, is nonsense, and you all know it, and can see it with your own eyes: we have managed to increase the concentration of CO2 in the atmosphere by 1/3rd (406 ppm compared to pre-industrial 280ppm) in the last 250 years. If CO2 really was the growth bottleneck, the CO2 concentrations in the atmosphere wouldn’t be increasing to begin with: the plants would simply absorb all of it and grow better. No, the temperatures are not going to help either: normal (C3) photosynthetic plants are harmed by high temperatures, which is why tropical plants had to evolve specific adaptations to survive.
And so, the reason why the Amazon rain forest needs the dust from the Sahara, is that its nutrients, if not immediately recycled, rapidly get washed away by the very rain that makes it such a lush place to begin with.
Washed away to where?
To the ocean, where life has originated. Where most nutrients are literally just dissolved in the water. The ocean that covers over 70% of our planet.
Prokaryotic* Protagonists
Let me introduce the main character to this saga. Apart from Big Oil of course, who brought us this mess to begin with, and will hopefully help us to clean it up, but more on that later.
Enter Microalgae*.
Between 50% and 80% of our oxygen comes from the ocean. The oxygen of about every 5th breath we take comes from diatoms, a type of algae that use silicon in their shells. A lot of the rest comes from the smallest photosynthetic (light-eating) organism alive, a cyanobacterium called prochlorococcus. If you eat fish, or any sea food, algae is where all of its carbon came from.
Because this is what eats most of our CO2. The photosynthetic algae and cyanobacteria are what absorbs most of the sunlight: more than 70 percent of Earths’ surface are oceans after all, and the algae have adapted to absorb sunlight at depths of over 250 meters (over 800 feet). They have also evolved higher light utilization efficiencies than land plants, probably due to their much more rapid life-cycles. Just like plants, they use the sunlight to split the oxygen atoms off the CO2, and use the carbon to build more of themselves. Then they get eaten by other organisms, like zooplankton. That gets eaten by bigger and bigger organisms, until finally, you get that nice tuna steak at the Japanese restaurant.
In and of itself, this is not a very fast process: under normal conditions, algae double their mass, and divide, every 24 to 26 hours. Under very favorable conditions, some seem to be able to do it every 3.5 hours. But to give you an idea how much algae we are talking about: Remember the prochlorococcus? The total mass of it in the oceans is estimated to be “as much as 220 million of volkswagen beetles”.
To put it differently: these cyanobacteria are producing more biomass per day than our entire car industry produces in car mass per year. And they do it all without our help, with renewable energy, by capturing CO2. They capture the CO2 by building machines that capture more CO2, out of that very CO2.
As long as we can not make factories to make factories that make factories, this is probably the best we are going to get.
But if they double this quickly, why do we even have any CO2 left? It must be the nutrients, right?
Almost.
High on Nutrients, Low on Algae
There are large swaths of the ocean that are rich in “macronutrients”, as phosphorus and nitrogen are called, but have surprisingly low concentrations of algae. Those regions are called High Nutrient, Low Chlorophyll regions. (Chlorophyll is the main “stuff” that makes plants, and algae, green, and allows them to absorb light.)
There are several theories why that is: maybe there is not enough light? Maybe the algae are getting eaten too quickly? (“Grazing hypothesis”).
There is, however, a correlation between dust storms and chlorophyll increases in those regions. It seems, it is about nutrients after all. Just not about macronutrients.
Here is the thing: the macronutrients dissolve well in water. A lot of micronutrients don’t. One of them is iron. Iron is absolutely necessary for photosynthesis, the very process that uses light to convert CO2 into oxygen and sugars. The HNLC regios are iron-deficient. There have been studies to confirm that it is indeed the iron that limits the amount of algae in those regions. It seems, every added iron atom leads to the capture of 25000–160000 molecules of CO2.
It seems, then, we have found a lever. This lever is called “iron fertilization”: suppying the already existing algae in the oceans with the missing nutrients, to enable them to multiply.
But will that not overwhelm the oceans? After all, what other organism can replicate so quickly, and consume all the new algae?
Salp can:
But will that actually capture the carbon? After all, they will just breathe the carbon right back out as CO2?
By the way, do check out that thread on Twitter, salps are fascinating creatures all on their own.
Carbon sequestration only considers the carbon that reaches the ocean floor as “successfully captured.” But this is not the entire story: apart from the carbon pellets slowly drifting downards, we would, of course, we be trapping more CO2 and energy in the cycle of marine life itself: giving us more algae, more salps, more fish, more marine mammals, like whales. More life doesn’t sound too bad for a project intended to clean up our mess, does it?
But does it work? Twelve separate small-scale studies show that it does. Maybe less effectively than the “Give me half a tanker of iron, and I will give you an ice age” adage of John Martin, the biochemist who discovered this process, but it does.
But how do we apply it? After all, a study on iron fertilization showed that “fertilizing 20% of the oceans 15 times a year will only remove 15ppm”. Wouldn’t the fertilization efforts produce CO2 of their own? Would it be worth it? Other researchers suggest that adding iron, i.e. removing the iron bottleneck, might deplete the ocean of other nutrients, and starve phytoplankton in other places.
A Lever Needs a Fulcrum
Here’s the deal. Why would we fertilize “15 times a year”? Why would we send ships with iron, and only iron, to fertilize the regions which we already know the limitations and compositions of? Why do our studies run from ships? And while we are at it, why should we dump all of the fertilizer in at once, and cause a massive, fish-killing algae bloom, that some of the opponents of ocean fertilization warn of?
There are hints that the sea floor already has most of the nutrients that we need. One of those hints is the correlation of seasonal algal blooms in shallow HNLC regions. The other is the chemical composition of the sea floor itself. We can emulate the natural mechanisms by taking the nutrient-rich sediments from the ocean floor, and distributing them in the ocean currents circulating in HNLC regions. Technology, and even the infrastructure to do this, already exist today. Unlike with the traditional approaches, due to the high leverage of (as mentioned, 1:25000 up to 1:160000 iron to carbon) we only need a small fraction of our worldwide industry and energy to move molecules around — most of the moving is done by the algae themselves, with the help of sunlight. They build their own infrastructure. Our, human infrastructure that I am talking about, is mostly unused, and should really not be used for what it was originally built for. Because what it was built for, was extracting deep-sea oil. I am talking about are the offshore drilling platforms.
Redemption for Big Oil
The oil industry already has the perfect tool for the job of getting out in the middle of nowhere, then reaching the ocean floor — as deep as 12000 feet (over 3.5 km) — and extracting minerals from there on a semi-permanent basis. It would need some changes — just like it would need some changes to pump CO2 into the oil wells to store it — but the basis for the infrastructure is already there, and paid for. We could start doing it today.
Yes, there are lot of “buts” and “what ifs”: Will this have side-effects? Of course it will. So will greening of the Sahara. So does us fertilizing our fields, and using the oil from the wells and coal from the mines today. By using oil, and coal, and gas, we are already running the largest, and the most dangerous experiment in human history, and we already know that the biosphere can’t cope — otherwise the CO2 levels wouldn’t be increasing. We are already changing the marine ecosystems by fishing the oceans empty— a third of the marine habitats are already over-fished. The coral reefs are dying due to the temperature rise, and due to ocean acidification — due to the increase in CO2 levels. Marine habitats are choking on our plastic pollution.
It is too late to argue for just waiting it out and not doing anything in the fear of changing something: we have been changing something — throwing wrenches into the nature’s works — for 150 years now, and we can see the damage accumulating with our own eyes. We should consider, instead, greasing Nature’s wheels for a change. By pumping nutrients up from the ocean floor, we would not be not putting anything new or artificial into the ocean that isn’t already there. We would simply accelerate a process that already takes place today. We would be helping the algae to do what they are already doing for us, in a controlled manner: capture the CO2 that we have released, and that will, otherwise, slowly kill them.
By starting with one research deep sea platform in a HNLC, we could study the effects on the local ecosystem. By releasing the nutrients continuously, instead of in massive bouts, we would be able to measure and control the effects. If we notice harmful effects, we could stop. If we notice that it is working locally, we could try another one. And another. And another. Until we utilize all 400 or so rigs that are currently unused. And then, the entire rest. All it costs to start to try, is one.
But will algae be enough?
We don’t know yet. But there is a theory that algae are at least partially responsible for Earth’s ice ages. We, on the other hand, don’t even need an ice age. We just want our climate to stop warming. And judging by the data the algae might give us a real fighting chance.
Consider the scale, and the other options we have, and you will find that this is truly the longest lever that we have. It is the cheapest option, and, given how we are not changing the total contents of the ocean, it might very well be the safest option, as well. Given our global unwillingness to change, and to pay for anything, this might also be our only one.
*A lot of sources talking about microalgae often include both true, eukaryotic microalgae, and the prokaryotic cyanobacteria — the grandparents of the chloroplasts found in true algae. For the sake of simplicity, we do this here, as well.
