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Technologies Can Scale

12 April 2024

Humans currently emit around 35 billion metric tons (35 gigatons) of carbon dioxide into the atmosphere every year. In case visualizing a metric ton of carbon dioxide gas doesn’t come easy for you, think of it the way the experts at the Massachusetts Institute for Technology suggest: “Imagine a cube 27 feet tall, wide, and long… a cube almost as tall, wide, and long as a telephone pole. That’s how much space it would take to hold a metric ton of CO2.” Furthermore, “this is literally a ton. While it may not seem like a gas can weigh that much, this 27’ x 27’ x 27’ cube has the same weight as a great white shark or, well, a ton of bricks (400 bricks!)” 

Of course there are numerous ways to reduce emissions, and the work of emissions reduction is happening in all sectors of society. However, approximately 30% of the world’s annual carbon emissions are generated from ‘hard to abate’ sectors such as steel, cement, aviation and even agriculture. These sectors are very hard to decarbonize because the release of carbon dioxide is inherent in their current industrial processes and we do not yet have viable decarbonised alternatives for them. For example, one of the main ingredients in cement is made by heating limestone to extreme temperatures. The process releases carbon trapped in the stone, which combines with oxygen in the atmosphere to form carbon dioxide. This is an unavoidable part of the dominant process in use for creating cement around the world today. 

Researchers estimate that even if society were to reach rapid decarbonization goals, 1.5 - 3.1 gigatons of carbon dioxide would still be released into the atmosphere every year from these so-called ‘hard to abate’ sectors. 

One role of carbon dioxide removal technology is to take care of the emissions from these hard to abate sectors, like aviation, steel, and plastics production as we continue to decarbonize all aspects of our world. Virtually all scenarios that limit global warming to 1.5°C or 2°C require carbon dioxide removal (CDR), however only a tiny fraction of carbon dioxide currently removed results from these novel CDR methods. These novel CDR methods include: Bioenergy Carbon Capture and Storage, Biochar, Direct Air Capture, Enhanced Rock Weathering and many others, and currently only remove 0.002 GT of CO2 annually (The State of Carbon Dioxide Removal). Research from Neil Hacker in Scaling Carbon Removal estimates that CDR technologies must grow at a rate of 46% compounded annually to reach 2050 climate goals.  

Source: The State of CDR

It’s ambitious, but we’ve scaled technologies before. The past 30 years offer excellent examples of technological scalability, from the widespread adoption of solar energy to the ubiquity of smartphones. By reviewing how these technologies were able to successfully scale up, we can glean valuable insights into the pathways for scaling carbon dioxide removal technology. 

The chart below was originally developed by Neil Hacker and offers a comparison of common technologies and the rate at which they scaled. 

Source: Neil Hacker, Scaling Carbon Removal

Solar Energy 

One of the most successful examples in the renewable energy sector is solar. In 1957 one megawatt hour of solar energy cost $300,000. Today, in sunnier parts of the world, it is considered the world's cheapest electricity source, costing $17 per mWh. As of 2021, both solar and wind are now cost competitive with fossil fuel electricity, and building new solar and wind projects are cheaper than building or operating coal-fired plants (WRI) . 

The sector has grown faster than many experts predicted due to the positive feedback loop of government incentive, favorable policies, changing public sentiment, and falling prices, but also in part due to the basically infinite consumer demand that any energy advancement will benefit from if prices get cheap enough. For the past 40 years solar has grown 40% annually and few technologies can claim such massive and persistent scalability,  but with looming 2050 goals CDR will have to scale faster. In Hacker’s notes on Greg Nemet’s book How Solar Energy Became Cheap he observes, “Solar was slowed down mainly by unstable and patchy funding and entrenched interests of incumbents.”  And in terms of scaling carbon removal, “Being cognizant of these for future innovations, while potentially very difficult to act on, would still be useful.”


Growing faster than any consumer technology in history, smartphone production has increased 26.4% annually since 1989.  When the iPhone was launched in 2007, it sold 11.6 million products in just two years and as of 2023 has sold 1.5 billion units worldwide. Enormous consumer demand has driven costs down allowing smartphones to scale rapidly, improve in quality of product, and shift cultural perspectives in record time - three milestones that novel carbon dioxide removal methods must achieve in the next 25 years. 

Consumer demand for carbon removal stands somewhere in between the demand for a luxury item like the smartphone or the inherent demand for cheap energy. At this time, carbon removal is not yet a mandated waste management system for governmental bodies, businesses, or individuals. To make up for this, the voluntary carbon market is creating the demand signal. In 2023 Microsoft committed to a forward purchase agreement to buy 2.76 million tonnes of carbon dioxide removal over 11 years. Other early adopters include Airbus, Frontier, Shopify, JP Morgan and Swiss Re which are responsible for the largest carbon dioxide removal with permanent storage purchases. According to the latest CDR.fyi tally in 2023 there were only 6 buyers that purchased over 100,000 tonnes of carbon removal; 14 others bought at least 10,000 tonnes. No doubt large corporate purchases continue to be necessary for the expansion of carbon removal, and many people working to accelerate the adoption of carbon removal are rightly focused on figuring out how to mobilize more corporate buyers. 

There is another important group to consider, however, and this is the public. The importance of mobilizing mainstream awareness and support cannot be underestimated. As the University of Manchester’s Rob Bellamy and his research partner from the University of Michigan, Kaitlin Raimie point out, “Carbon removal methods are not simply technical objects, they are combinations of technical objects and social arrangements that work together as a single system. Carbon removal methods simply will not work without an implementation context: purposes, people, institutions, policies, politics, procedures, and so on.” (see Communicating on Carbon Removal). The public must be engaged for true expansion to occur, and in large enough volume, individual consumers may also constitute a powerful demand signal. Their engagement in any case, is necessary to build the mainstream support necessary to push for the formulation of policies that will help mobilize additional investment from governments and the private sector. As leading direct air capture supplier Climeworks has observed, “Incremental, small-scale initiatives have the potential to generate substantial real-world effects, emphasizing the necessity for early adoption to scale high-quality climate technologies.” The Tomorrow’s Air approach to engaging the public is to find them when they’re planning and budgeting for travel. Research indicates that 70% of travelers care about climate change and would like to be part of a solution.

We have every reason to believe that a consumer movement in support of necessary climate innovations like carbon removal and sustainable aviation fuel is possible. After all, we’ve seen people band together to achieve all sorts of goals from improving working conditions to restoring ecosystems. (see The Power of Collective Action in Addressing the Climate Crisis)


Scaling Carbon Removal, Neil Hacker
CDR FYI Market Summary Report
The Carbon Removal Show: Analogies for Scale
W.R.I: Explaining the Exponential Growth of Renewable Energy
The State of CDR
Booking.com: Cost vs. Conscience
Frontiers: Communicating Carbon Removal
MIT: How much is ton of CO2
Bloomberg: Microsoft Inks Deal to Pay for CO2 stored below the Sea
Statista: Apple’s Iphone Revenue
Textedly: Smartphone History
Energy Transitions Commission: Mission Possible