Carbon capture is a dangerous concept


The  carbon papers

The carbon cycle is a beautiful thing.  And as usual Nature does it best. For a million years carbon moved around the cycle untroubled by those pesky anthropocene intruders.

Although the majority of the carbon on land is stored in the soil, trees breathe carbon in and out in the form of carbon dioxide. What goes up generally comes down, and atmospheric carbon in the form of carbon dioxide, CO2, stayed pretty much at the same level for millenia. Concentrations in the air varied with the seasons, but on average concentrations of CO2 in the atmosphere stayed about the same.  That’s the land-based bit.

Then out over the oceans there is a slower gas-liquid exchange between CO2 dissolved in sea water and the CO2 in the air.  Once again there is a dynamic equilibrium–which means that carbon comes and goes but average concentrations in the air and in the ocean stay about the same. This is actually the fast bit of the cycle–meaning variations that can be measured and tracked over the course of a year.

Then there’s the really slow bit.  So slow you hardly know its there.  This is the movement of carbon between soil, rocks, the ocean and the air.  This part of the cycle is seriously slow : 100 to 200 millon years to make the round trip.  But it’s still a lot of carbon that gets slowly moved around. It was like this for millions of years.

It’s just small change

So what happens when homo sapiens enters the picture?

First of all – not much of anything. The invention of agriculture doesn’t seriously disrupt the carbon cycle.

Then he discovers coal.

Coal is part of the slow carbon cycle.  It’s not part of the plant biosphere breathing carbon dioxide in and out; it’s not part of the carbon cycle that runs through the soil; and it’s not part on the air-ocean, gas-liquid exchange. It’s an intruder in the fast carbon-cycle space.

Burning coal injects massive quantities of carbon into the atmosphere. Into the fast carbon cycle. Concentrations of CO2 in the atmosphere shoot up. A lot of the gas is absorbed by the oceans–but that increases the acidity of the ocean water.  Air-liquid exchange rates rise but at higher equilibrium concentrations–there is more carbon in the atmosphere in the form of CO2 and there is more carbon in the ocean in the form of carbonic acid. On land, the higher CO2 levels in the atmosphere may actually promote plant growth.

But there is a looming and existential threat.

Higher levels of atmospheric CO2 changes the Earth’s energy balance. This is a scientific fact. This has a rock-solid scientific foundation and a million precise measurements to prove it. No amount of pseudo-scientific nonsense and claptrap from the coal companies and the oil industries can change this fact.

So now look what’s happening.  Burning coal, oil, natural gas and any carbon-based fuel pushes immense quantities of carbon into the atmosphere in the form of CO2. Into the fast carbon cycle–where it has nowhere to go but into the air and into the oceans.

Powering down

So could carbon capture and storage work?  No problem to remove carbon dioxide from power station flue gases.  But where to put it?

Let’s see….Where do we put most of our garbage?  The general idea is to put it someplace we can’t see it.  That way we can forget about it.  This usually means we chuck it in the sea, or we bury it.

So lets try pumping it underground and see if it stays put.  Because somehow it has to be locked away. Out of sight, out of mind–an excellent concept. Safely locked away into the slow carbon cycle.

For this to work the carbon has to be absorbed into a mineral substrate that will chemically bind with the CO2. Conceptually this is possible. Except that it has never been done before. And if it is to make a serious difference to atmospheric CO2 concentrations, it will have to be done on a massive scale.  It’s all new technology.  Expensive?  Of course: billions. And guess what?  It takes huge amounts of energy to make it work.

How about methanol?  If we can make methanol or some other useful chemical from carbon dioxide surely that’s a game changer?  Well no, it’s not.  Because unless this carbon is removed from the cycle almost permanently, it is still going to show up at some point in the atmosphere–and then in the ocean. That’s why it’s called a cycle.

You have to take a step back at this point and say: Whoa, why are we even thinking about doing this?

But we know why.  The coal companies want us to buy their coal and the oil and gas industries want us to buy their fuels.  These are the dirtiest, filthiest industries ever invented by mankind but, boy, do they ever make money. What do they care if the planet is buckling under the strain? Business as usual is a very profitable enterprise.

But there’s a new kid on the block.  Wind power and solar energy are now less expensive than coal and oil, and at about the same level as power generation from natural gas.

So the question to be answered is this: why are we still burning carbon?

Why are we still using filthy, carbon-based, fuels that foul the environment, pollute the air in our cities, and insinuate trace metals like mercury into the bloodstreams of our children.  Check out the web if you’re not convinced.

We don’t need carbon-based fuels. The only people that really need coal and oil are the people that have become wealthy from using it.

And if we are not going to use carbon-based fuels, why are are we spending hundreds of millions of dollars developing carbon-capture technologies?

Sweeping the chimney  

There is an energy revolution taking place. A paradigm shift.  But like all revolutions, the entrenched beneficiaries of the status quo will fight to keep their place.

You can tell it’s a war because the first casualty, truth, has already been carried off the battlefield.

Carbon capture is scientifically unsound, commercially risky, demonstrably unnecessary, and inherently wasteful.

Spend the money on clean energy technologies that inject nothing into the carbon cycle. Protect the forests that breathe and replenish the air. Replant the mangroves that absorb three times more carbon that tropical biomass.

But there is not much time left. Keeping global warming to less than 2 degrees has already been shown to be almost impossible. This is not the time to be looking for ways to resuscitate a moribund technology whose time has passed.






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