To avoid the devastating effects of climate change, it’s become clear that reducing emissions simply won’t be enough. Successive waves of climate-enhanced disasters (flooding from Vermont to South Korea, the first tornado in Delaware in 40 years, and Canadian wildfires that blanket the sky across wide swaths of North America with smoke) have been layered on top of the hottest years on record to highlight an emergency that can no longer be ignored.
The global benchmark to avoid the worst effects of climate change is set at maintaining global temperature increases below 1.5 degrees Celsius. This necessitates cutting greenhouse gas emissions to nearly zero by 2050. Although there has been significant positive momentum, the world is not on track to meet this goal. One reason is that some hard-to-abate industries—including architecture, engineering, construction, and operations (AECO)—rely on exceptionally energy-intensive processes that spew carbon emissions to refine, transport, build, and operate projects. For example, the many tons of steel and concrete produced for buildings and infrastructure—and the need to move these heavy materials vast distances—is one reason AECO is one of the largest contributors to carbon emissions in the economy.
Decarbonizing these industries will take time, meaning that emissions will continue to be released into the atmosphere between now and then. Meeting climate goals thus can’t happen by simply reducing future emissions. In March 2023, the Intergovernmental Panel on Climate Change (IPCC) reported that keeping global temperatures within 1.5 degrees of preindustrial levels is highly unlikely without removing gigatons of CO2 that are already in the atmosphere. The only sustainable way forward is a "yes-and" approach that pairs future reductions in greenhouse gas emissions with a vital and relatively underdeveloped and underinvested sector: carbon dioxide removal.
Carbon removal is the process of sequestering carbon dioxide already in the atmosphere and permanently storing it. Removal can result from purely natural processes, such as trees sequestering CO2 through photosynthesis, or a technological intervention, such as air-capture arrays that pull carbon dioxide out of ambient air. In either case, the purpose is to turn back the clock, removing carbon dioxide from the atmosphere to prevent the effects of global temperature change.
To be clear, carbon removal is not a replacement for reducing emissions in the first place. It’s absolutely critical to prioritize investments that lead to a deep decarbonization of the economy. In addition, solutions that remove and store CO2 from the atmosphere need to be scaled with urgency. An entirely new carbon-removal industry needs to emerge from near zero.
Currently, the carbon-removal sector is a small fraction of the global economy, representing a market in the single-digit billions. A successful climate transition means scaling carbon removal from a billion-dollar industry to a trillion-dollar industry, on par with the size of the oil and gas sector today. That rapid scale-up requires meaningful private-sector investment and innovation, as well as public-sector support, to catalyze and de-risk this growth.
Today, most carbon removal happens through conventional and natural processes, such as carbon sequestration in trees. Only 0.1% of carbon removal results from technologically or human-engineered methods. Across both nature-based and technological approaches, the industry needs to scale up by a factor of roughly 1,300x; estimates vary, but roughly to removing between 5 and 16 billion metric tons of carbon dioxide per year by 2050. (For context, the United States alone emitted just over 6 billion metric tons of greenhouse gases in 2021.) Humans need to transition from removing metric tons of carbon each year to gigatons and doing so in a timeframe that meaningfully addresses climate change.
Scaling the carbon dioxide removal industry to gigatons isn’t without its challenges, both regulatory and technical.
Measurement, verification, and reporting standards will need to continue to evolve to ensure trust is protected. Talent pipelines will need to be built to develop the right competencies and skills. Markets will need to emerge that value and transact on carbon, flowing capital to the most promising solutions. Sequestered carbon will need to be stored safely and permanently. And entirely new regulatory and permitting procedures will need to be invented to ensure that the carbon-removal process happens equitably, with consideration to the places and communities most affected by climate change. In general, a new set of public policies must set parameters for efficiency, efficacy, timescale, and more.
Perhaps the most pressing challenge today is that a true market needs to emerge—the industry needs to demonstrate strong demand to entice further investment. Aggregated purchase orders from private-sector clients or public policy shifts that require this technology could set a strong baseline for this emerging market.
The good news is that there are natural systems that already sequester carbon as part of the Earth’s natural carbon cycle. Scientists and entrepreneurs are willing to learn from these systems to launch and scale up solutions. Whether novel carbon-removal techniques harness these natural processes directly or translate them to entirely synthetic means, they’re all grounded in the Earth’s natural carbon cycle.
Trees and plant life of any sort are a massive source of carbon sequestration, and tree planting has long been understood as a way to fight climate change. (Additionally, wide adoption of mass timber in the building industry would spur demand for an effective carbon remover.) Once this biomass dies, however, it decays and releases its carbon, so carbon-removal methods that deal with natural processes and biotic matter seek to halt this rerelease.
One way might be plant genetic modification: Scientists have found ways to genetically alter rice so that its roots reach straight down instead of spreading out horizontally. By reaching deep into the soil, these carbon-sequestering roots don’t break down and decompose, releasing carbon into the atmosphere as they rot.
Biochar is a material made from a wide range of biotic matter—especially agricultural waste products (rice hulls, nut shells, and so on) that, when heated to high temperatures in a low-oxygen environment, create a carbon-rich, charcoal-like material. Biochar is highly stable, allowing the carbon to be stored for hundreds or thousands of years. Burying it underground or sprinkling it around crops has the dual benefit of keeping potential atmospheric carbons locked inside for hundreds of years, both nourishing the soil and reducing the need for fertilizer. While it’s best to harvest waste products for biochar (food waste from homes or restaurants is one potential source), biochar can be made from nearly any biotic matter: wood, leaves, even animal manure. Applied Carbon is using artificial intelligence–assisted robots to deposit biochar in soil.
Direct air capture (DAC) systems cycle air across carbon-sequestering materials. Climeworks’ Orca is the first commercially available DAC unit, and its pilot project is powered by geothermal energy in Iceland. Fans draw in air and pass it over a porous material that binds CO2 to its surface. To extract the carbon, the unit is heated to 100 degrees Celsius, and the concentrated carbon is stored underground via mineralization, where it is mixed with water and merges with basalt rock formations, turning into stone. One unit can extract 10 tons of CO2 from the air each day.
Heirloom runs the first DAC facility in the United States in Tracy, CA, and its method accelerates the natural process of carbon sequestration from air to limestone rock from years to days. It heats crushed limestone in a kiln, separating it into carbon dioxide and calcium oxide powder. The carbon dioxide is extracted and stored and sequestered into concrete, made by CarbonCure Technologies. Then, the calcium oxide powder is mixed with water to form calcium hydroxide. This powder is spread over trays that absorb carbon dioxide from the air over three days, becoming limestone once again. The cycle is then repeated. Heirloom projects that this method will cost less than $100 per ton by 2035.
Vesta is looking to rely on the natural mineral olivine to increase carbon-sink capacity along coastlines. The company plans to accelerate the natural chemical weathering of olivine by spreading large amounts of the mineral—ground into sand—onto coastlines, where it dissolves into the water, increasing the rate of CO2 absorption. As an alkaline material, olivine can also help counter ocean acidification spurred by climate change. This is an example of enhanced mineralization to address carbon removal. Basalt is another example: Studies have shown that agricultural land treated with ground basalt-captured carbon is more productive.
The draw of bio-oil is simple: It holds the potential to put carbon-spewing oil back into the ground where it came from. Charm Industrial uses agricultural byproducts from corn harvests that have already sequestered carbon and converts them into a stable, nonflammable, viscous liquid called bio-oil. Similar to biochar, this oil is made by heating biomass to 500 degrees Celsius in a few seconds without igniting it. The oil is then pumped underground, often into the same wells from which it was pumped. It’s very stable and solidifies into a rock in days or weeks after injection. Charm Industrial’s light infrastructure allows it to operate close to agricultural fields to minimize its transit carbon footprint.
The ocean holds more carbon than any other part of the biosphere, and one of the most cutting-edge, experimental attempts to remove carbon there uses electrochemistry to do the job. In this method, seawater is pumped through an electrochemical system, and water and salt molecules are rearranged into acidic and basic (alkaline) solutions. The basic solution is returned to the ocean, increasing oceanic alkalinity and pulling CO2 out of the atmosphere into the ocean. The acidic solution can also be used to pull CO2 from seawater.
The quote, “change starts from within” accurately reflects how businesses can help grow the carbon-removal industry. Businesses should:
Understand their own carbon footprint to determine how much carbon their operations are directly or indirectly emitting.
Take accountability for that carbon footprint, exploring credit purchases as a way to neutralize emissions.
Explore areas where the business can uniquely support the growth of the ecosystem for the benefit of stakeholders like employees, suppliers, and customers.
Syndicate demand together through advance market commitments (more on those below).
Advocate for government engagement and support.
Advance market commitments (AMCs) are emerging tools used to fund the carbon-removal industry and drive down costs so that carbon removal can be more ubiquitous and reach a mass market at the gigaton level. In terms of carbon removal, these arrangements entail buyers in the private or public sector who can guarantee their purchase of carbon-removal services en masse over a specified time. This process sets a baseline demand needed to signal a safe investment and helps these emerging technologies attract funding in a less risky environment. This framework was initially pioneered to develop vaccines in developing nations.
AMCs are essentially turning nebulous commitments to sustainability into contracts to buy carbon removal. Made up of a consortium of technical experts, the AMC invests buyers’ money in a wide range of carbon-removal companies. When the specified tons of CO2 are removed, the AMC pays suppliers and issues credit back to buyers.
One major benefit to this approach is that it spreads risk among a diverse group of carbon-removal vendors. But the primary value lies in the market seeing high-volume investments that aggregate funding and demand from many sources in one burst rather than in incremental drips. Autodesk has joined with other investors to invest $100 million in the Frontier AMC to support the carbon-removal industry, just a small fraction of the $1 billion commitment this consortium has made to buy carbon-removal services.
The carbon-removal industry has largely been established through private-sector investment, as part of wide-ranging corporate commitments to decarbonize business operations. Autodesk has neutralized the emissions across its business and value chain since 2021. Microsoft has been carbon-neutral since 2012, is committed to carbon-negative operations by 2030, and has secured contracts to remove 2.5 million metric tons of carbon dioxide from the atmosphere. The real estate services giant JLL is set to achieve carbon neutrality across all of its buildings by 2030. Likewise, Apple has committed to shift all electricity used in its supply chain to renewable sources by 2030.
Much of this activity is predicated on carbon credits and offsets, wherein organizations that do carbon-reduction work can issue credits and corporations that emit carbon can buy in exchange for continuing to reduce greenhouse gas emissions, offsetting their own carbon footprint and subsidizing more decarbonization.
But this is an imperfect approach, as it can be challenging to verify impact and potentially creates a mechanism to delay decarbonization. It’s not possible for an organization to simply offset its way out of this problem. Additionally, a wide variance in quality means that credit purchases might not earn the carbon savings they’re counting on. If a credit is issued by a forestry organization practicing sustainable forestry and conservation, and it is then purchased by a company a continent away, what regulatory measure would prevent the trees that are supposed to be protected from being cut down? In terms of carbon removal, the difference between these two decarbonization methods are stark: One avoids putting greenhouse gases into the atmosphere, and the other removes greenhouse gases already in the atmosphere.
The evolution from paying $1,000 a ton to $50 per ton for carbon removal will require a major effort from both the private sector and the public sector, which will be called upon to set the regulatory climate while curbing its own emissions. Nearly half of all emissions in the United States and European Union are the result of public procurement.
The public sector often finds it harder to adopt new technologies and processes than the private sector and is not subject to the same pressures that force innovation; this context is key in the emerging field of carbon removal. But the public sector can offer greater levels of data transparency and communication.
In the near term, it’s critical that governments update their suite of environmental permitting regulations and performance standards to set the table for carbon-removal growth. Next, the public sector will need to build management oversight capacities and protocols, as well as set specific KPIs to benchmark success at the policy level. Finally, there is a public mandate to systematically report and analyze progress and setbacks, verify that performance and compliance standards are being met, and build alliances among the full range of public sector organizations invested in carbon removal.
Domestically, the Biden administration’s Department of Energy is awarding up to $1.2 billion for commercial DAC—the world’s largest single investment in carbon removal. Project Cyprus is part of this package, which will enlist Climeworks, Heirloom, and the applied science and technology organization Battelle to install a DAC facility in Louisiana. The administration is also committing $2.5 billion for forest fire restoration, $2.5 billion for the storage of CO2, and $2.1 billion in low-interest loans for CO2 transit infrastructure.
There’s significant movement on carbon removal in Europe, as well. The UK was one of the first nations to establish a greenhouse gas removal goal of 5 million tons by 2030, and it plans to invest 20 billion pounds ($26.5 billion) in it over 10 years. Meanwhile, Portugal is the only European Union country that has enshrined carbon-removal targets into law.
In Canada, the oil-rich province of Alberta is making a $1.24 billion investment in carbon removal, attaching this fledgling industry to the oil-refining process. The developing world has seen activity, too. In the central African country of Cameroon, NetZero is producing biochar using agricultural waste from the coffee industry. Located next door to the nation’s largest coffee-processing plant, it has abundant access to coffee-cherry husks that are usually discarded as waste; the biochar produced here (as much as 2,000 tons per year) can be used by local small-scale farmers to improve soil health, in addition to decarbonizing the atmosphere. NetZero has opened a second facility in Brazil, which has double the capacity of the first facility.
The burgeoning field of carbon removal emerges not just as an option but as an imperative. To counter the relentless march of climate change, businesses must integrate and innovate within this nascent industry, scaling it to meet the daunting scale of the global carbon footprint. A mature carbon-removal industry with the capacity to restore balance to the world’s ecologies is a place where every decision is carbon driven and every economic actor is reducing carbon emissions at every scale.
There’s a collective responsibility to ensure that this technology is democratized and that organizations large and small have access to the tools they need. The commitment of both the private and public sectors to expand and refine carbon-removal technologies is vital. Businesses are called not only to innovate but also to act, ensuring a future when technology and nature coalesce to forge a sustainable legacy for generations to come.
Zach Mortice is an architectural journalist based in Chicago.
PD&M
Image courtesy of Heirloom.
Executive insights
AECO
Image courtesy of Iwan Baan.
