It’s widely recognized that significant reductions of greenhouse-gas emissions, accomplished through such means as switching from fossil fuels to renewable energy and preventing deforestation, are necessary to prevent cataclysmic climate change. Now, it’s increasingly clear that realizing a pathway to 1.5°C of warming will also involve removing carbon dioxide from the atmosphere.
Some methods of achieving carbon-dioxide removals, or “negative emissions,” are available today. These take two main forms: engineered solutions, such as direct-air capture (DAC) and bioenergy with carbon capture and storage (BECCS); and natural climate solutions, such as reforestation. While research suggests that it is possible to achieve substantial carbon removals with negative-emissions solutions, it will take significant investment to build markets and infrastructure to the scale expected in several 1.5°C warming scenarios.
To illuminate the opportunities and challenges associated with negative emissions, McKinsey spoke with five people who are deeply engaged in the field: Shaun Fitzgerald, director of research, Centre for Climate Repair at Cambridge University; Emma Gibbs, partner, McKinsey; Jens Price Wolf, general manager Europe, Enviva; Amy Ruddock, VP Europe, Carbon Engineering; and Karl Smyth, head of bioenergy with carbon capture and storage (BECCS) strategy and engagement, Drax. In this article, we offer highlights from those conversations. Remarks have been edited and condensed for clarity.
Why are negative emissions important?
Emma Gibbs: The best analogy is walking into a bathroom and seeing an almost full bath with the taps still running. The first thing you would do is turn off the taps. You would reduce the emissions going into the atmosphere. But even if you were able to turn the taps off completely, you’d still have a full bath. So you’d also want to take the plug out. And negative emissions are basically like taking the plug out.
Negative emissions aren’t a substitute for emissions reductions. The most important thing to do to tackle climate change is reduce emissions. But negative emissions do play a really important role alongside reducing emissions to help meet the aim of not letting temperatures rise above 1.5° over pre-industrial levels.
Shaun Fitzgerald: There are three reasons we need negative-emissions technologies. The first is because of the damage we have inflicted upon the climate. Today, we are at something north of 500 parts per million of carbon dioxide equivalent. Pre-industrial, we were at 270. We’ve already put too much up there. The second reason is that we’re not turning the emissions taps off fast enough. It’s going to take us a while to transition to a zero-emissions or near-zero-emissions economy. And third, we’re never going to get those taps fully off. In very hard-to-abate sectors, such as agriculture, we’re going to need negative emissions to counterbalance the emissions that will continue at some level in the foreseeable future.
What negative-emissions solutions are available now? And how do they work?
Emma Gibbs: There are many methods under development: enhanced weathering, no or low till farming, storing more carbon dioxide in the oceans. And that’s great because we are going need lots of different solutions. The three that we’ve spent the most time looking at, because they are ready to scale right now, are natural climate solutions, bioenergy carbon capture and storage (BECCS), and direct air capture and storage (DACS). Those three are pretty well-proven, and they have the potential to remove the large quantities—gigatons—of carbon that we need to remove in the coming decades.
Natural climate solutions are what you would expect: they’re based in nature, such as reforestation. You plant trees, and they absorb the carbon dioxide.
Jens Wolf: BECCS is also a way of using nature’s own capture technology. Plants capture CO2 from the air and build it into their plant material. As we use the plant material, the CO2 is released again—but we catch it with technology called carbon capture, and we either use it instead of fossil fuels or put it back into the ground for storage. The net effect is that the plants take the carbon out of the air, and we put it away so it doesn’t return to the atmosphere.
Karl Smyth: We use bioenergy for a range of different energy solutions, today from clean electricity to renewable fuels. By installing carbon capture and storage technology onto those industrial processes, not only do we get a clean product like clean electricity or clean hydrogen, but we also take CO2 out of the atmosphere.
Amy Ruddock: Direct air capture takes carbon dioxide directly out of the atmosphere and stores it permanently, safely and securely, deep underground. It is a feasible, affordable negative-emissions technology that can be implemented with equipment that’s been used in industry in other applications for many years, which means we can deploy at scale rapidly now.
Why is it helpful to build a portfolio of different negative-emissions solutions?
Shaun Fitzgerald: No single approach we know of right now looks like it’s going to be of sufficient scale on its own to address everything. Perhaps even more important, we still don’t know all of the potential negative consequences of any negative-emissions technology. Therefore, it would seem highly prudent to look at a number of technologies that we can start to build out and learn not only about the benefits but also the negative consequences so that we can dial one up, dial one down, as appropriate, as part of our risk management strategy in tackling climate change.
What’s the urgency in scaling negative-emissions solutions?
Karl Smyth: A new report from the Coalition for Negative Emissions shows that to achieve the volume of negative emissions we need by 2050, we need to start ramping up production today. The report shows that even by 2025, we’re at risk of being 80 percent off target relative to where we need to be. So we need industry and government to work together to drive investment in some early projects, which we can then use as a baseline to scale up in the 2030s and beyond so that we can have a sustainable global scaleup of negative emissions in the volume we need by 2050.
Amy Ruddock: The operative word for negative-emissions technologies is “now.” We can’t bet on technologies suddenly being available in the 2040s and the 2050s. If we don’t get these solutions up and running now, we’re not going to hit that S-curve of learning and be ready by 2050 at the scale that we need to be. It’s not just building plants that takes time, it’s creation of the market, it’s creation of commercial contracts, it’s creation of standards, it’s resourcing the thousands of people needed to engineer, operate, and maintain plants.
Jens Wolf: There are technology issues to be resolved with negative emissions, and if we wait, we risk having to accelerate development at such a pace that it will be very expensive and difficult. By starting now, we give ourselves the time to develop the technology.
Emma Gibbs: Developing all of these different solutions takes time. Planting one tree doesn’t take very long. But to reach the 2050 numbers, we’re talking about reforesting an area ten times the size of the U.K. Or we’re talking about building six times as many DAC plants as there are automotive plants. Or we’re talking about having the same number of BECCS plants as about a third of the world’s coal power-plant fleet at the moment. So we’re talking about a lot of infrastructure development to deliver the scale of negative emissions that we need. All of this is going to take time. If we get started now, there’s no reason we can’t meet the 1.5°C pathway.
What should happen to scale negative-emissions solutions?
Jens Wolf: To scale up negative emissions, we need to put a value on it. I think using a carbon contract or a similar regulatory instrument is the way forward to make sure investors in negative emissions have a longer period of time where they can guarantee the value of the essential product that they’re producing. It requires significant investment, but I think a number of companies are very enthusiastic about doing it as long as they can see a future for their technology.
Emma Gibbs: On our current trajectory, we are not going to hit the 2030 target for the 1.5° pathway. There are a number of reasons for that, but a lot of it has to do with a kind of chicken-and-egg problem in scaling the markets for negative emissions: there aren’t enough suppliers of negative emissions, so there isn’t really a market that’s liquid and transparent for people to be able to trade negative emissions. And there isn’t much demand because it’s difficult to engage with those markets. So, there’s not much reason to invest in it because there isn’t much demand. That’s the cycle that we need to break if we’re going to reach the gigaton scale of negative emissions that we know is going to be important to—along with reducing emissions—meet the 1.5° pathway.
Amy Ruddock: When corporates get involved in negative-emissions technologies like direct air capture, what they’re doing is helping us solve the chicken-and-egg problem. At the moment, there are plant developers who want to build plants. There is private finance that wants to go into those plants. But nobody today is paying you to take carbon dioxide out of the atmosphere—there’s no certainty of revenue stream that is needed to unlock that infrastructure investment. And then on the other hand, you have corporates looking at their net-zero strategies and seeing a supply constraint. Corporate commitments are going to continue to send those demand signals, and they’re also sending a signal to governments that they see this as important.
Shaun Fitzgerald: Current technologies alone are not going to be of sufficient magnitude to cope with the negative emissions that we’re going to need as a future society. So, we need more research, such as looking at how we remove methane from the atmosphere. All of the approaches we’ve described don’t deal with that. It may well transpire that some of the things that are deployable today may not be the answer in the longer-term.
There’s also a huge amount of work that needs to be undertaken that is way beyond just development of technology—a whole research agenda. We need to think about how whatever we do regarding the development of negative-emissions technologies supports as many of the United Nations’ 17 Sustainable Development Goals as possible. So, they will include things like improving the health of mankind, trying to reduce social injustice—the big, societal factors.
What’s the case for organizations and companies to engage with negative-emissions solutions?
Emma Gibbs: In addition to neutralizing hard-to-abate emissions—both for themselves and their supply chains, which can be complicated—some companies are suggesting they would like to go even further than net zero and become carbon negative by taking out all of the carbon they’ve ever put into the atmosphere since they’ve been in operation. That is a bold commitment and can only be done through negative emissions.
Shaun Fitzgerald: All of us, all institutions, all countries have a responsibility for future generations. So, I think the first thing is to recognize that whatever we do on negative emissions, or reducing emissions in the first place, the people who are going to benefit most are going to be the next generations. And I think it’s important that we, therefore, take responsibility for the world and for future societies, because what we do now in the next five, ten years is going to have a massive impact on future generations. That’s, for me, the driving force for development of negative-emissions technologies.
About the interviewees
Amy Ruddock is the VP Europe at Carbon Engineering. Jens Price Wolf is the General Manager Europe at Enviva. Karl Smyth is Head of Bioenergy Carbon Capture & Storage (BECCS) Strategy & Engagement at Drax. Shaun Fitzgerald is Director of Research at the Centre for Climate Repair at Cambridge University. Emma Gibbs is a partner in McKinsey’s London office.