What is Carbon Removal?
Carbon Removal—Cleaning up carbon dioxide from the air.
Synonyms are carbon dioxide removal and negative emissions.
Excess carbon in the atmosphere is causing climate change. There is already too much. To solve climate change, we need to stop creating new carbon emissions (a.k.a. traditional mitigation), and we have to clean up the mess we already made by removing carbon.
To clean this carbon up, we must remove it and store it away from the atmosphere.
What are the Leading Carbon Removal Solutions?
Carbon Removal Solutions—technologies or processes that capture carbon dioxide and store it permanently. Carbon removal solutions can be divided into nature-based and engineered solutions.
Nature-based solutions employ photosynthesis to capture CO2 from the atmosphere. Photosynthesis draws in carbon dioxide, storing it within sugars, plant fibers, tree wood, and soils. It has successfully stored carbon for billions of years! Carbon farming, forest management, and increasing forests all maximize carbon storage.
Engineered solutions employ technology to capture CO2 from both "point sources," like coal fired power plants, and the atmosphere. This captured CO2 is then permanently stored in rocks, building materials (like cement), or underground reservoirs. Direct air capture, carbon capture and storage (CCS), and enhanced carbon mineralization are examples of technological solutions that can reliably and efficiently remove carbon.
More Frequently Asked Carbon Removal Questions
- How much do carbon removal approaches cost, and what is their scale potential?
- What role will carbon removal techniques play in the fight against climate change?
- Why should we invest in developing carbon removal solutions today?
- What are the largest challenges facing the carbon removal field?
- Who are the leaders in the carbon removal field today?
- Which carbon removal approaches are best suited for private-sector investment today?
- By "carbon removal," do you mean "carbon capture and storage?"
- By "carbon removal," do you mean "geo-" or "climate-engineering?"
How much do carbon removal approaches cost, and what is their scale potential?
Today, cost and supply estimates for carbon removal approaches are highly uncertain, as most carbon removal technologies have not entered large-scale commercial deployment. In addition, more systems-level analysis of carbon removal approaches is needed to assess global scale potential. A handful of academic estimates of carbon removal potential have been published, which have been compiled in the illustrative supply curve graphic below.
Why pursue carbon removal?
Carbon removal techniques provide a critical option for mitigating climate change—they provide a complement to other GHG abatement techniques, not an alternative:
Without carbon removal, we cannot overshoot our carbon budget and still prevent significant climate change, defined by scientists as a 2 degrees Celsius rise in mean global temperatures:
The scientific consensus on the need for carbon removal as an option in the fight against climate change has grown increasingly strong:
Increasingly, carbon removal approaches are not only critical for keeping global temperatures below 2°C but also deployed heavily in modeling scenarios that involve 3+ °C climate change. Major uncertainties exist as to the viability and scalability of the carbon removal techniques assumed in these scenarios. Because existing technologies cannot generate negative emissions, it is critical to resolve these key uncertainties surrounding carbon removal approaches that have such great impact on our ability to prevent climate change.
Why should we invest in developing carbon removal solutions today?
Carbon removal technologies may not deliver the greatest short-term carbon impact per dollar spent on GHG abatement today, but there still remains a large imperative to invest in these technologies today for several reasons:
1. The carbon removal field today is much more nascent than other GHG abatement fields, and investments in R&D in the field today could increase the competitiveness of carbon removal approaches in the future considerably. In many ways, the carbon removal field is reminiscent of the solar energy field in the 1970s:
Many energy and environmental technologies follow "learning curves" which require considerable investment in deploying technologies before they can be produced at economically-viable costs:
2. Only carbon removal approaches are capable of generating negative emissions. If we find that we need large scale negative emissions sooner than expected, it will be critical to have viable, scalable carbon removal developed, as more mature GHG abatement techniques cannot provide negative emissions.
3. Carbon removal offers more opportunities for companies and countries to fight climate change. The greater the opportunities we have for fighting climate change in economically and politically viable manners, the greater the likelihood that multilateral cooperative action to prevent climate change will materialize.
What are the largest challenges facing the carbon removal field?
Many different approaches to achieve carbon removal have been proposed, but considerable research and development is needed to understand which approaches can be scalable, cost-effective, and sustainable:
Which carbon removal approaches are best suited for private-sector investment today?
There are good business cases to make for a number of potential carbon removal strategies today, including:
- Conservation and restorative agriculture and forestry
While the true carbon removal potential of some of the above approaches is uncertain, these investment can be profitable and have positive environmental/social impact regardless of carbon sequestration potential.
There are also profitable investments in carbon negative "pathway" technologies (i.e. projects that are not carbon negative but can de-risk and develop critical elements necessary for carbon removal solutions), including:
- Fossil CCS / Bio-CCS for enhanced oil recovery
- Low carbon cements/plastics
- Fuel synthesis using direct air capture
What is critical for investments in these technologies is ensuring that learning from "pathway" approaches is translated into fully carbon-negative systems in the near future.
By "carbon removal," do you mean "geo-" or "climate-engineering?"
No. Most carbon removal approaches fit the popular conception of "mitigation" much better than the popular conception of geoengineering. Here at Center for Carbon Removal, we focus only on carbon removal mitigation approaches. Check out this blog post for more info.