CLIMATE CHANGE
Explainer: What is direct air capture and how can it fight climate change?
Apr 21, 2023
This article is published in collaboration with
Reuters
Small particles of a material derived from limestone are seen on a tray for capturing carbon.
Direct air capture technology uses chemical reactions to remove carbon dioxide from the air.
Image: REUTERS/Nathan Frandino
Reuters
Share:
OUR IMPACT
What’s the World Economic Forum doing to accelerate action on Climate Change?
THE BIG PICTURE
Explore and monitor how Climate Change is affecting economies, industries and global issues
A hand holding a looking glass by a lake
CROWDSOURCE INNOVATION
Get involved with our crowdsourced digital platform to deliver impact at scale
Stay up to date:
Climate Change
The US government is offering $3.5 billion in grants to companies that capture carbon dioxide using a process known as direct air capture (DAC).
DAC technology uses chemical reactions to remove carbon dioxide from the air, allowing it to then be stored in underground caverns or used in applications such as making concrete.
The main selling point of DAC compared with carbon capture technology used at industrial sites is that it can pull historical emissions out of the sky.
But some groups are concerned that DAC gives fossil fuel companies cover to keep up production, especially in minority and low-income areas near heavy emitting facilities.
As the need for climate action intensifies, governments and industries are exploring how to remove carbon dioxide (CO2) from the atmosphere.
The U.S. government has offered $3.5 billion in grants to companies that will capture and permanently store the gas using a process known as Direct Air Capture (DAC).
Here’s how the cutting-edge technology works, along with it potential and limitations.
How does it work?
DAC technology uses chemical reactions to remove carbon dioxide from the air, which can then be stored in underground caverns or used in products or applications such as making concrete or aviation fuel.
The world’s largest operating DAC plant, Climeworks’ Orca plant in Iceland, can remove 4,000 tonnes of CO2 a year, which is then stored deep underground.
The U.S. programme is seeking to fund large-scale plants capable of removing a million tonnes a year.
What about trees?
Natural methods of carbon removal such as planting trees and forest management are expected to play a huge role in helping combat climate change. Doing so is relatively inexpensive, at less than $50 per ton, according to the World Resources Institute, compared to technology such as DAC, which currently costs in the high triple digits per ton.
Many scientists, however, believe technical solutions will be needed, partly due to the amount of land that would have to be taken up if all the required removals were made through using trees.
Are there other types of carbon removals?
Other techniques include bioenergy with carbon capture and storage (BECCS). Through this method, electricity is produced by burning biomass like wood pellets and capturing and storing the emissions generated during the process.
Biochar is a form of charcoal produced when organic matter such as leaves, wood or straw is heated at high temperatures without oxygen, leaving a carbon rich substance that can be used as fertilizer, thereby storing the carbon in soil.
Techniques are also being developed to remove CO2 from seawater.
Have you read?
Companies are sucking carbon from the atmosphere using ‘direct air capture’. How does it work?
The level of carbon dioxide in the atmosphere has hit a record high, according to the UN
What about CCS?
Carbon capture and storage (CCS) technology is traditionally deployed at industrial smokestacks such as fossil fuel power plants, filtering out the CO2 and storing it before it reaches the atmosphere.
Unless the CCS technology is capturing more CO2 than the industrial process is emitting at the site it would not usually be deemed a removal.
The main selling point of removals compared to CCS is that it can pull historical emissions out of the sky and store them in soils, rocks, trees, oceans, and products, moving beyond emissions reductions to permanent removal.
DISCOVER
What’s the World Economic Forum doing about the transition to clean energy?
What do green groups think?
While most environmental activists acknowledge some carbon removals will be needed for global climate targets to be met, they are concerned companies could use carbon removal development as an excuse not to reduce their emissions by as much as possible in the first place.
Many green groups also question the use of biomass for electricity and are sceptical over technological solutions such as DAC.
Some groups are focused on the environmental justice implications of DAC, concerned that the technology gives fossil fuel companies cover to keep up production, especially in minority and low-income areas near heavy emitting facilities.
Don’t miss any update on this topic
Create a free account and access your personalized content collection with our latest publications and analyses.
License and Republishing
World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.
The views expressed in this article are those of the author alone and not the World Economic Forum.
