It has been billed as an ingenious solution in the battle against climate change.
And from photos alone, the true purpose of the ‘Mammoth’ machine stationed in Iceland may deceive you.
The 360ft contraption, located at Hellisheidi, about 15 miles from capital Reykjavik, is literally sucking carbon dioxide (CO2) from the air.
Developed by Zurich-based firm Climeworks, the ‘direct air capture’ (DAC) site uses huge steel fans to draw in CO2, dissolve the gas in water, and pump it deep underground.
Scientists at Climeworks say the multi-million dollar system removes up to 36,000 tons of carbon per year – equivalent to taking 8,000 cars off the road.
And the UK government is so impressed with the technology, it’s planning a carbon-British carbon-sucking machine based in the north-west.
However, critics warn that the expensive tech does not tackle a root cause of global warming – the release of CO2 from burning of fossil fuels.
Environmental organisation Greenpeace has called carbon capture a ‘scam’ that relies on money from ‘the public purse’.
Mammoth, which started operations in May 2024, consists of stacks of metal ‘air scrubbers’ that suck in CO2 from surrounding ambient air using fans
Swiss firm Climeworks unveiled its second plant in Iceland sucking carbon dioxide from the air and stocking it underground, scaling up its capacity tenfold with the aim of eliminating millions of tonnes of CO2 by 2030
About 10 times bigger than its predecessor plant Orca, Mammoth began construction in June 2022 and operations commenced in May last year.
Mammoth consists of stacks of metal ‘air scrubbers’ that draw in surrounding ambient air with fans, using energy from a nearby geothermal power plant.
Solid filter material separates the CO2, which is then transported by jets of high-pressure blasts of water to a location deep underground.
Over a few years, the CO2 turns into a solid mineral called carbonate when it touches certain rocks that are rich in metals like iron, calcium and magnesium.
It therefore stores it safely as a solid underground, reducing the amount of the greenhouse gas that reaches the atmosphere.
Climeworks explains: ‘Through natural mineralisation, the CO2 reacts with the basalt rock and turns into stone within a few years.
‘The CO2 is thus removed from the air and returned to Earth permanently and safely.’
Climeworks said the technology can easily be replicated at different locations worldwide and on ever larger scales, to scale up the amount of CO2 being captured.
Mammoth in Iceland removes up to 36,000 tons of carbon per year – roughly equivalent to taking 8,000 cars off the road
And the UK government is so impressed with the technology, it’s planning a carbon-British carbon-sucking machine based in the north-west
The resulting mixture of CO2 and water is injected into the volcanic basalt beneath the plant where it slowly turns into rock
At its maximum capacity of 36,000 tonnes of CO2 per year, it could reduce global emissions by the equivalent of 7,800 petrol-powered cars.
However, that impressive figure is only equivalent to 30 seconds of the world’s annual CO2 emissions – which is why they’re being considered elsewhere around the world.
Inspired by Mammoth, the UK government has begun negotiations with Climeworks based in Zurich to set up an equivalent machine, called Silver Birch.
The device, to be constructed in Stanlow near Liverpool, would suck carbon from the surrounding air and store it under the Irish Sea.
The plans, being developed by the Department for Energy Security and Net Zero, come under the HyNet North West project to reduce carbon emissions and help the UK hit its net zero target.
But for now, the two HyNet projects being prioritised are a new new gas-fired power station with carbon capture technology in Wales, and a biomass plant in Cheshire that will generate low-carbon energy from waste wood.
The exact cost of building a plant like Mammoth is unclear, although Iceland’s impressive store of natural resources mean it can afford such ambitious climate projects. Douglas Chan, COO of Climeworks, told The Chemical Engineer that the cost to build was ‘in the order of low triple digit millions’.
Mammoth, which started operations last year, is about 10 times bigger than its predecessor plant, Orca
Climeworks did not detail the cost per ton of removal at Mammoth, but said it is seeking to reduce it to $400-600 per ton by 2030 and $200-350 per ton by 2040.
Aside from the cost, carbon capture and storage (CCS) has been criticised for encouraging continued use of carbon-belching fossil fuels rather than switching to renewable sources of energy.
Mike Childs, head of policy at environmental organisation Friends of the Earth, said the government is just ‘championing more costly and dirty fossil fuels’.
‘Even if it ever worked, which is unlikely in the near term, CCS won’t capture all the climate pollution caused by burning fossil fuels or address the significant emissions that are created when gas and oil is extracted.’
Stuart Haszeldine, a professor of carbon capture and storage at the University of Edinburgh, called CCS projects ‘a deal with the devil’.
‘Storage of 2 or 5 million tonnes CO2 per year should not become a policy excuse to release additional 10s or 100s million tonnes CO2 from development of new oil and gas extraction through many tens of new licences,’ Professor Haszeldine said.
Others point out that the process itself is very energy intensive and so could drive up energy prices.
The technology also has safety concerns – after being stored underground, some experts fear that CO2 could leak and taint nearby water supplies or create tremors caused by the build-up of pressure underground.
