How capturing CO2 from air can combat climate change
FT environment correspondent Leslie Hook gets behind the scenes at Climeworks, a Swiss company with ambitions to remove one per cent of annual global carbon dioxide emissions from the atmosphere by 2025
Produced, filmed and edited by James Sandy
Think about climate change and you may not picture the foothills of the Swiss Alps. But one company here is trying to save the planet one carbon dioxide molecule at a time. Their name is Climeworks. And their business is pulling carbon dioxide out of the air.
So Louise, tell me what is happening here at this facility around us.
Sure, what we have behind us is a Climeworks direct air capture plant. Here, we have 18 CO2 collectors. They draw ambient air through in this direction. And the CO2 molecules essentially stick to the filter material inside there. And once that filter material is saturated, is full of CO2, then we close the collector, we heat it to about 100 degrees Celsius, and the CO2 then unsticks.
Once the CO2 unbinds from the material, it can be syphoned off, leaving the filter free to collect more. This plant is able to capture 900 tonnes of CO2 every year. But it takes heat and electricity to work.
And where does this facility get the energy that powers this process?
In this particular set-up, we're using energy from waste. So we've built these plants on the roof of a waste incineration plant. And through the burning of the rubbish, energy is generated and we make use of that energy to power our direct air capture machines.
Some of the CO2 that Climeworks captures is injected underground. The company already has a facility in Iceland, where the CO2 is pumped into basaltic rock and mixed with water to form solid carbonate, effectively turning it into stone. But the core of their business right now is selling the gas to be used again.
The CO2 that Climeworks is capturing just a few hundred metres away, it is pumped through an underground pipeline directly into this greenhouse. And you can see the black pipes hanging below. That's where the CO2 is released into the greenhouse.
And what role does it play when it arrives here?
Vegetables, plants, they love CO2. They require it for photosynthesis. And so with higher concentrations of CO2 within the greenhouse, the better those plants can grow. This particular greenhouse has seen an increased crop yield of 20 per cent.
There are only three start-ups in the world that operate direct air capture facilities. And Climeworks was the first to land paying customers. But they're a long way from achieving their ultimate goal, removing 1 per cent of global annual CO2 emissions by 2025. To do that, they'll need customers who want to sequester CO2 rather than just reuse it.
At present, there is no market for carbon dioxide removal. So the real exam question is, how do we generate a market where one doesn't exist right now from a standing start? Until that happens, the capacity for the negative emissions market to develop to the scale that's needed, of gigatonne scale, will be highly problematic.
Climeworks believes there's a huge potential market for captured CO2 if they can drive down costs to a level that's attractive. Working with new technology and on a small scale means it costs $600 to remove a tonne of carbon dioxide from the air. For them, the challenge is to make their product cheap enough to be rolled out on a large scale.
What about the costs? There are critics who say that currently the costs are too high and that it will never be economical enough to really impact climate change.
Our goal as in what we are working towards, which we are very confident also that we can arrive during the next couple of years, is taking a tonne of CO2 out of the air at a cost of around $100 per tonne. And that's what we believe is the same level at which policies will be active, and that will on the very large scale pay for removing CO2 from the earth. So that is then a level where we can scale to the gigatonne level, which is required to have an impact.
Scientists estimate that by 2050, we will need to be removing 10bn tonnes of CO2 from the atmosphere every year in order to limit the worst effects of global warming. Direct air capture isn't the only way to do this, but it could be one tool among many.
With today's technology, direct air capture is still uneconomic. And critics say it can never be built on a large enough scale to make a difference to the climate. But at a time of rising emissions and rising global temperatures, more people are coming around to the view that this technology does have a role to play.