Comment: Direct Air Capture - Fact v Fiction

Direct Air Capture has a lot of responsibility on its shoulders — and so evokes criticisms and misunderstandings, with some more valid than others. The first to address is that it’s distinct from Carbon Capture and Storage (CCS), which aims to capture new carbon emissions from an emitting source — making it carbon-neutral. DAC is carbon-negative, and instead refers to recovering CO2 already in the atmosphere. Other accusations include it being a greenwashing tactic, an inherently inefficient process, and just a way for companies to distract from slow progress on decarbonisation.

Sometimes, the critics are right. If powered by non-renewable energy, used as an excuse to burn more fossil fuels, or done via unsustainable technological processes, DAC can have a negligible or even a net-negative impact on climate. However, the best examples of today’s DAC tech are efficient, sustainable, and a vital part of a much broader climate mitigation strategy.

DAC is more than a greenwashing tool for the energy industry

Energy companies have long delayed investing in renewable energies without moving away from fossil fuels — culminating in June 2024’s unwelcome record 40 gigatonne amount of emitted carbon. At the same time, energy companies have boasted about investing into DAC and CCS — with many suggesting the latter distracts from the former.

The bottom line is that energy companies should be doing far more to reduce emissions, and should be spending less money and effort protecting the longevity of the oil and gas industry and ‘business as usual’ beyond its natural lifespan.

However, in isolation, using carbon neutral (CCS) or carbon-negative (DAC) technologies to reduce the emissions of the energy we need today can only be a positive thing. It’s down to regulators and policymakers to ensure energy companies don’t let this investment detract from broader decarbonisation efforts.

DAC is not a moonshot miracle — it is one piece of the climate puzzle

Another common criticism is that it can distract from more meaningful action. The most impactful things we can do to reduce emissions right now are often the simplest, such as insulating homes. However, even if we could press a switch and immediately become 100% renewable now, we would still likely breach the 1.5C degrees temperature limit (if we haven’t already).

While it’s critical we do more to reduce carbon emissions, we've already released too much carbon. The IPCC has said that to meet the goal of staying below 1.5C of warming, we will need to remove between 100-1,000 billion tonnes of CO2 from the atmosphere by the end of this century. This reality makes DAC a critical technology alongside nature-based carbon removals and dramatic emissions reductions.

DAC has come a long way — and it’s only becoming more effective

The last criticism to address is one of efficiency. DAC is accused of being too energy-intensive, so when powered by a grid that is largely fuelled by fossil fuels, you end up emitting more carbon than you recover. 

Yet, renewables are perfectly capable of powering DAC and the technology is becoming much more efficient — something which is only going to improve. As an example, Mission Zero Technologies expects its DAC process to reach total plant energy consumption of less than 1,000 kWh/tCO2 within the decade thanks to continued development and falling componentry costs.

As with any technology, improving energy efficiency requires innovation, investment and time. A common industry aim is to be able to remove CO2 for $100 per tonne, which will likely be achieved with a mix of technical innovation and government tax credits. The industry in general is showing clear progress, with many projects aiming to soon reach a levelised cost of $300 per tonne of carbon recovered.

Electrochemical DAC, for instance, can flexibly increase or reduce energy consumption. This allows energy developers to minimise wastage from renewable sources during peak production hours when there is so much renewable energy generation that it outstrips demand — which in the UK amounted to 1.3 TWh of wind power between October 2022 and January 2023, or enough to power 1.2 million homes.

Reimagining our relationship with carbon

DAC also plays a key role in producing essential carbon-based products that we otherwise couldn’t make without using fossil carbons — and these industries, like aviation, construction and agriculture, are nearly impossible to decarbonise entirely by 2050. Indeed, many of the products and industries we rely on require a steady source of CO2 to operate.

Currently, the process for sourcing CO2, mostly from natural gas, is unsustainable and polluting, with supply often very inconsistent. The UK wasn’t alone in witnessing the commercial CO2 shortage in 2021, which threatened food supply chains due to its vital role in refrigeration. DAC, on the other hand, could produce a much steadier supply of CO2 given it’s not linked to the price of natural gas.

DAC will only become more effective

The last thing critics should remember is that DAC is only getting better; better at removing carbon, cheaper to operate and scale, and more energy efficient. With a global effort to direct more investment into the right technologies and create a more effective regulatory landscape, DAC can have an exponentially positive impact for industry and climate.

Shiladitya Ghosh is co-founder and COO at Mission Zero