Carbon Capture Machines - a solution to climate change?

What are they?

Carbon Capture Machines use a technology called Direct Air Capture (DAC).

They suck CO2 out of the air and trap it into stone deep underground.

There are two approaches:

1. A fan pulls in air and the CO2 molecules are trapped in a solution as carbonate salts and removed from air.

2. A sponge like air filter absorbs CO2 from air which is then reheated and released into storage.

Why are they important?

The Intergovernmental Panel on Climate Change (IPCC) states that to prevent severe global warming we need to reduce our current and future CO2 emissions but also remove historical ones.

According to engineers, the DAC technology has a lower risk of leaking CO2 from underground and re-releasing it to the atmosphere.

World's largest carbon capture machine

The world's largest carbon capture machine is in Iceland.

It is called "Orca" which is the Icelandic name for "energy".

The captured CO2 is injected 1 km underground into volcanic rock.

There it reacts with the basalt and forms solid carbonates.

Orca can capture 4000 t of CO2 per year.

Are they really a solution? Problems

For now DAC is only applied in small scale environments.

To make a real difference it needs to be scaled up by a lot.

If we want to be below the 1.5 °C limit, we would still have to remove 5 to 14 billion t of CO2 each year from 2030 onwards.

Orca captures 10 million times less CO2 than our current global emissions.

So Orca's yearly CO2 removal is cancelled out by our global emissions every 3 seconds.

We need to consider how expensive will DAC be and how much this technology helps. Even more, how much are we allowed to alter nature by storing CO2 in rocks? And is there another solution?

Sources

ABC Science, the guardian