CDR might be necessary, but we should only focus on it after we have fully decarbonized

Why we have to parallel-track our mitigation efforts.

Decarbonization and carbon dioxide removal (CDR) are not antagonistic but synergistic. We absolutely have to do both. Here we discuss why we cannot wait with CDR until our economy is fully decarbonized.

The bottom line

Opponents of CDR often frame the discussion as an either-decarbonization-or-CDR decision. This is a false dichotomy. We have to do both. Decarbonization is crucially important and rightfully most investment goes towards decarbonization. But we have to start ramping up CDR now so it is mature and scaled by mid-century when we’ll need it at a large scale.

Scale-up has to start now

We might repeat ourselves here, but we’ll say it one more time so it really sinks in: There is no effective CDR without decarbonization. Any CO2 molecule we do not emit, we do not need to remove.

While cities, states, countries, companies, and industries work on (or delay) decarbonization, we continue to emit CO2 on the gigaton scale and will continue for some time to come. Some sectors are harder than others to wean off of fossil fuels and–realistically–some level of CO2 emissions will be with us for a while.

Here is another point that bears repeating: we know we will need CDR at a massive scale by mid-century so we can begin the work of undoing the damage we have done. Most (probably all) CDR approaches are not yet mature enough to be deployed at the massive scale that’s needed, and to get them there in the coming decades, we need to invest now. We need to develop them so they can someday be deployed widely at a fraction of today’s cost.

We know it can be done–we’ve seen it happen with solar energy–and we know what it takes: money and time. Every dollar we invest today will reduce the overall cost and shorten the timeline to achieve the capacity we need.

Solar - a perfect example

Solar panels were few and far between even ten years ago. They were expensive and people were reluctant to deploy them. This has changed dramatically: “the cost of solar/photovoltaic has come down by 82% between 2010 and 2019” [link].

Assuming a similar rate of cost reduction, even the most expensive CDR approach to date, direct air capture, would cost $90 per ton of removal within ten years. $100 per ton is considered the threshold for CDR to be economically feasible.

Decarbonization - easier said than done

Opponents of CDR claim that “all” we have to do is to decarbonize our entire economy. However, decades of experience have proven that this is far from trivial. In fact, decades of experience show failed emission reduction targets and broken promises rather than the progress we need.

The pace of decarbonization that is required to meet the Paris temperature targets vastly exceeds anything in the historical record at the global scale.

Moore, F.C., Lacasse, K., Mach, K.J. et al. Determinants of emissions pathways in the coupled climate–social system. Nature 603, 103–111 (2022). Determinants of emissions pathways in the coupled climate–social system | Nature

Countries, states, companies, and individuals have shown to be very slow - and sometimes outright hostile and resistant - when it comes to making the necessary changes and adjustments. What little progress we have seen comes mainly through voluntary action or because the green alternative is also economically advantageous (e.g. renewable energy is cheaper than fossil fuel-based energy). The wast majority of people and companies in the high-emitting countries have not experienced any inconvenience, let alone hardship, related to decarbonization.

While we need to continue to aggressively push for decarbonization it is naive at best to assume that we can “just” change people’s attitudes and behaviors fast enough to achieve the necessary emission reductions. It is equally unrealistic to assume we will enact and enforce laws that severely restrict the use of fossil fuels.

The COVID pandemic provides an instructive example. Despite data that unambiguously show that vaccinations have short-term, personal benefits (not needing emergency care, not dying) about one in three people in the US are not fully vaccinated and vaccine mandates have been fought all the way to the Supreme Court. If encouraging rational behavior (getting vaccinated) has such a high failure rate for something of fairly immediate personal benefit, the chances of successfully and quickly changing behavior about something as abstract and intangible as climate change are very slim at best.

We have to do both

Saying that we have to decarbonize and only once that is done start removing CO2 is creating a false dichotomy. They are not mutually exclusive and there is no reason why we can’t do both in parallel.

Both actions support each other and have the same goal: dramatically reducing CO2 concentrations in the air. Importantly, they are actually synergistic with decarbonization focusing on not making things worse and CDR on cleaning up the mess we already made.


We need to decarbonize and invest in CDR. The longer we wait to get a portfolio of different CDR methods off the ground, the more expensive it will be, or–worse–we will not succeed in scaling up quickly enough, with catastrophic consequences.


“[W]hat we need to do is integrate carbon removal as a part of our decarbonization and adaptation efforts. For if we have the newfound capacity to remove carbon from the atmosphere and put it elsewhere, do we not have the responsibility?”

Professor Holly Jean Buck, University of Buffalo [Link]

“All pathways that limit global warming to 1.5°C with limited or no overshoot project the use of carbon dioxide removal (CDR) on the order of 100–1000 GtCO2 over the 21st century.”

Special Report: Global Temperature Change of 1.5 C - A Summary for Policymakers, C.3. (2018)[Link]

“Unless affordable and environmentally and socially acceptable CDR becomes feasible and available at scale well before 2050, 1.5°C-consistent pathways will be difficult to realize, especially in overshoot scenarios.”

Special Report: Global Temperature Change of 1.5 C - Chap. 4 Strengthening and Implementing the Global Response (2018). [Link]

Contrary to claims that carbon removal is fundamentally at odds with other strategies, we can spend the next decade simultaneously deploying available clean energy technologies and scaling up removal strategies.

We can also move past the debate over whether we have all the technologies we need. Pilot-scale and commercial projects exist for almost all emissions sources, even for harder-to-abate ones. We’re unlikely to reach ambitious goals like net-zero emissions without making use of all technology and policy tools at our disposal and without continued investments in research and development.