As communities are feeling the damaging consequences of climate change, many people hope for an easy solution, like the farcical giant vacuum cleaner employed in “Space Balls-The Movie” to provide clean air for a planet that squandered its own. Far from science fiction, very real carbon dioxide removal (CDR) technologies are launching a dynamic new industry, and the primary customers are companies who see CDR as a tool to reach their net zero commitments. Yet CDR is not a magic vacuum—only a promising technology whose ultimate impact depends on continued development and responsible use. For those unfamiliar with CDR, here are four things you need to know:
Carbon dioxide removal means physically removing existing carbon dioxide emissions from ambient air and storing it away permanently. Physically capturing carbon dioxide can take many forms, ranging from highly mechanized fan and sorbent systems to nature-based solutions like fast growing kelp. Likewise, permanent storage takes many forms, including pumping carbon dioxide into stone formations below the earth to sinking it to the deep ocean floor. True CDR meets high standards for additionality (these emissions would not leave the carbon cycle on this timeline without human action), verifiability (the captured carbon dioxide can be precisely measured), immediacy (the impact on the stock of emissions happens now and does not rely on future actions) and permanence (carbon is locked away for hundreds or thousands of years).
Carbon dioxide removal is different from most carbon offsets and from carbon capture and use. The three key components of CDR—physical removal, ambient air and permanent storage—make CDR different from more familiar emissions management tools. For example, carbon offsets often rely on hypothetical “avoided emissions” to estimate the net impact of a project, or capture carbon into temporary storage like trees that take time to reach their full potential and might burn or simply shift deforestation to another location. By contrast, carbon capture attempts to remove carbon at the source of emissions (like a scrubber in a smokestack); it is a practice that theoretically could reduce emissions but has been less effective and more costly than expected. While captured carbon can be repurposed into green fuel or as inputs into industrial processes—a potentially important part of a circular economy—this use often does not qualify as removal because the captured carbon continues to circulate through the atmosphere.
Carbon dioxide removal is appropriate to neutralize emissions that cannot be avoided—not an excuse to continue business as usual. The hard work of decarbonization requires that all companies avoid generating emissions in the first place: by improving efficiency, changing behaviors and switching to renewable power and clean fuels. But after all of that, some emissions cannot be entirely avoided. CDR can bridge the gap by neutralizing unavoidable emissions. CDR will become greenwashing if companies use carbon removal as an excuse to ignore their obligations to reduce their emissions to begin with.
The carbon dioxide removal industry is growing fast and poised to accelerate. This growth is evident in the number of deals, the number of buyers and the number of companies selling carbon removal projects, all of which continue to increase each year. The first wave of companies have established a viable proof of concept, and a nascent second wave is building modularity, efficiency and agility needed for the industry to really take off. In parallel, a cadre of consultancies, standards boards, government regulations and incentives and grassroots supporters combine to create the supporting infrastructure that is helping the industry mature.