De-Hyper: Can 3D Printing Alone Solve the Climate Crisis? Probably Not.

Given the compounding human-caused, ecological crises facing life on earth at the moment, I’ve been interested in speaking to experts to understand what role, if any, 3D printing and technology can play in stalling, mitigating and/or reversing those crises. Among them is Manfred Lenzen, Professor of Sustainability Research at Integrated Sustainability Analysis (ISA) in the School of Physics at the University of Sydney.

Prof. Lenzen has a PhD in Nuclear Physics and has spent 15 years dedicated to renewable energy, including passive solar architecture. Having focused also on input-output analysis and lifecycle assessment, Lenzen has also developed a deep understanding of the intertwined relationship between human activities and their impacts on the larger ecosystem.

A 3D printed heat exchanger like this one could be used to optimize temperatures in a direct air capture system. Image courtesy of GE Research.

Most recently, Prof. Lenzen co-authored a report, along with other leaders in the sustainable energy and economics space, which questioned the feasibility and potential negative impacts of many of the technological solutions being proposed by the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC) and others to address ecological breakdown, such as negative emissions technologies like direct air carbon capture and storage (DACCS) and bioenergy with carbon capture and storage (BECCS). Instead, the authors urge a “post-growth” approach, particularly aimed at high-income countries, in which societies’ economic growth is redirected toward social welfare.

In this article, we’ve provided the full transcription of our interview with Prof. Lenzen. In a follow-up article, we will discuss the role of 3D printing and technology more specifically as it relates to the ongoing ecological crisis.

GE Aviation’s 3D printed fuel injection nozzle.

I began by telling Prof. Lenzen about the paragon of 3D printing case studies: the 3D printed jet fuel nozzle by GE-Safran joint venture CFM International. This component not only demonstrates the ability of additive manufacturing (AM) to improve labor and production efficiency by reducing the part count of an assembly from 12 to just one, but also fuel efficiency. The nozzle is meant to cut fuel consumption by about 15 percent, in turn reducing greenhouse gas emissions from aircraft by 15 percent. This served as a jumping-off point for a wide-ranging conversation that began as follows:

Prof. Lenzen: I need to make a few qualifications. The first one is, of course, that I’m not an expert in 3D printing. I have no idea what can be done with this. Also, I’m not an expert in aircraft fuel efficiency. I’ve read that the options for making planes even better are limited because, for the industry, fuel is a very high proportion of their costs anyway. So, they’ve done quite a bit to reduce your cost. And recently, as far as I’m aware, efforts have gone more to substitute in conventional fossil-based fuels with bio-based fuels or blends.

Anyway, I’m not really an expert on this. But, in the context of the paper that you’ve read, what we have found is, if there are savings that are brought about by technological means—if they save costs by using, for example, as you described less fuel in an aircraft—if they reduce cost, they have been so far invariably accompanied by subsequent increases in the volume of consumption.

That means, in other words, the money that has been saved because of technological progress has been spent elsewhere, [which results in] more greenhouse gas emissions occurring elsewhere through other consumption channels. This effect is called the “rebound effect”.

An illustration of the rebound effect. Image courtesy of Energy Central.

3DPrint.com: Is that rebound effect specific [to a given company that reduces cost savings]? Are you talking about specifically one company or one industry or the global energy usage in this case?

Prof. Lenzen: What I mentioned is more globally relevant because that’s what the scope of our study was. There are reviews out there on the rebound effect and it’s accepted that the rebound effect exists and is strong. For example, I can remember one study that was done quite a while ago. The authors analyzed emissions reductions associated with reducing military defense spending, if the money was recycled into households by giving them a bigger tax break.  The result was that greenhouse gas emissions would increase because households would then re0spend that money on things that are more greenhouse gas intensive than national defense.

These studies normally do not focused on a specific company, but are specific to the sector. For example, I can send you a paper that I’ve done for Australia, where we looked at, for example, [fossil fuel-derived] hot water versus electric hot water, or meat versus vegetables, and so on and so on. It doesn’t need to be necessarily so that the rebound gobbled up all the savings in emissions that have been achieved, but it is often so that the actually savings effect is greatly diminished because this money is spent elsewhere.

3DPrint.com: That’s interesting because there are a lot of progressive people in the United States, for instance, that talk about cutting defense spending for various reasons, including the fact that the U.S. military emits the most carbon dioxide of any institutional user, supposedly, in the country. And, so, you’d think that if you cut the defense budget, that could lessen the amount of emissions there, but then it just pops up elsewhere, which I guess is what you’re getting at in this latest paper.

Could you discuss how it’s the lifestyle overall more than the specific usage of the energy that causes these emissions? I know you that’s not the case entirely. As you said, the rebound effect is stronger in some industries than others, but maybe you could discuss how it’s that society itself in the developed world that is creating the emissions and not necessarily one aspect of that society.

Prof. Lenzen: Well, there’s quite a large body of literature that links lifestyle to emissions. And this is summarized in a recent paper in Nature is a review of environmental and social impact in trade. Also, there’s a recent paper out that is a scientists’ warning on affluence. The second one is probably more relevant in this context and that shows—and it ties in with the rebound effect—simply the tendency of people to consume more as time goes on is what is really at the heart of the problems of keeping emissions down. Now the mainstream reaction to this is to throw technology at this problem. But the issue is that the increase in personal consumption has, for the last four decades, completely outrun any technological progress.

It’s quite a simple calculation. Emissions are driven up by two factors: affluence and population. This is related to the concept of which nations have driven emissions down by technology—that’s the carbon intensity of production. So, population has increased emissions by about half a percent per year on and it’s a declining effect. Technology has driven emissions down by about 2% per year. But affluence has driven emissions up by itself by about 3%. So, that’s affluence up at 3% per year, population up half a percent per year, and technological progress is down 2% per year. And you get you know a net effect of one and a half percent up every year. And that’s the rate that we see emissions growing.

This consumption and affluence paradigm is driving emissions and we haven’t been able to outrun this. It doesn’t look like we will get the technological progress that we need to make. At least there is no evidence for this.

So, what the de-growth people then conclude is that we need to activate an additional lever, which is consumption. And that is tying back to the rebound effect. That means consumption is somehow [taken away] and not replaced with something else. It’s the same argument to say, “We can’t use coal. Even if we have it in the ground, we just need to live in the ground.”

Having said this, I’d like to stress that the notion of foregoing consumption doesn’t mean foregoing quality of life. It’s a fallacy to equate living standards with quality of life, but they are actually not related. And there’s a lot of evidence to show that consuming less doesn’t mean your wellbeing declines—quite the opposite in many cases. Having more income does not increase your wellbeing. It’s really flattens out to what’s high incomes. And, in many societies, like in the U.S., for example, well-being has even been declining as income increases.

3DPrint.com: I have a couple of follow-up questions. The first one is what is the proposed solution to enact that limit on consumption? How would you propose going about doing that?

Prof. Lenzen: That’s a great question. It’s a hard question. I guess it’s the million-dollar question. You can see it permeating throughout the paper that you’ve read. We think that to ramp up technology or to decouple growth from emissions—which is typically tied to negative emissions technologies, such as DACCS or BECCS—is becoming increasingly unrealistic. And it’s increasingly risky because it’s a gamble because if we gamble on those technological solutions and they don’t work, then we’re in trouble. And that’s why I was suggesting an additional lever.

So, the question is, is this additional lever any more realistic than the existing technological leaders like expanding renewables or decoupling or DACCS or BECCS?. That’s a good question.

An infographic describing bioenergy with carbon capture and storage (BECCS). Image courtesy of one earth.

I’ve talked to a lot of people who say it isn’t. They say, “It’s just not in human nature not to consume and no politician would touch it because, as soon as the nation just scaled down a little bit, that politican would be voted off in the next election.”

So, this is very difficult. It could be framed in a way that you say that scaling down is actually good for you. For example, at work, and think about what people ask you to do and why you’re doing them and think about the things you buy and then make a list of those that you think that you could do without, but you don’t really need. I need you to cross them off the list. How much less money would you spend an hour? Much less money. Now that’s crucial because what you need to earn to lead the life that you would lead. Then, if needing to earn less money results in less stress, that’s the mechanism [we need to focus on].

It needs to be framed, of course, and it’s very difficult to frame because any loss or any reduction is viewed with negativity, according to human psychology. The avoidance of loss is so much a stronger objective in humans. Economists have showed this in many case studies that we must be careful how to frame degrowth as a gain of quality of life rather than as a loss of material living standards.

Still, even having thought about it, it’s still hard to do this. And it may well be unrealistic, as well, but even if it is unrealistic, the point that we’re still not even talking about a degrowth scenario in the IPCC’s scenario suite. So, at the very least we could add another scenario to the already-unrealistic or increasingly-unrealistic levers considered by the IPCC.

3DPrint.com: I know some people who are familiar with and proponents of degrowth are concerned that degrowth will be deployed as a strategy, but that it will be done in a way that’s not equitable or benevolent to people. You could say that for the last year or so, we have been in a period of minor degrowth imposed by all the restrictions and everything associated with COVID-19 and the supply chain issues. Is there a concern that economic shrinkage could be inequitably imposed?

Prof. Lenzen: That’s another good point you’re making. If you have any fiscal policy that is aimed at curbing carbon emissions, that is already a restrictive measure that is imposed top-down onto everybody. Whether it’s a carbon price or carbon tax, it is a top-down fiscal measure that is imposed on people. So, that’s not anything new. Of course, COVID is much more. COVID was responsible for a 6.4 percent drop in global carbon emissions in 2020. That should tell you something about the extent to which we’d have to restrict economic activities if we were to reach the necessary GHG reductions.

And I doubt that this can be done. At the moment in Australia, we see this feature that if you don’t motivate these restrictions, you don’t get people’s buy-in. You go to great lengths in “Look, the reason we are staying at home in is to save lives.” They get nurses from COVID wards up on stage for the COVID briefings and tell the public how our lives depend on staying home.

So, I agree with you that that is not what the degrowth proponents want to do this impose restrictions. However, if we don’t get on that track with technology or with the growth, then these things will be imposed—not necessarily by force. At some stage, and it depends on the temperature trajectory, the restrictions will be imposed because of extreme weather events where you simply cannot travel because those means of travel are temporarily or permanently disrupted and so on and so on.

You mentioned equity, which is actually a game changer in this debate because as you know there are large parts of the world’s population that have these those low levels of per-capita emissions. We cannot ask to reduce even further because they have real needs to improve, not just their material living standards, but their quality of life. We’re talking about the electrification of villages and so on. Of course, they can leap-frog us to avoid the bad technology developments, but that takes climate finance, from the global north to the south itself. And it takes additional reductions in the developed world because, at the moment on a per capita basis, emissions are so much higher and so much above the current global average. So,  the financing and the reductions have to come from high-income nations.

3DPrint.com: It seems that economic growth is inherent to the global capitalist system. The firms that run things will have a pretty serious problem with trying to shrink instead of continuing to grow. Would we have to basically up-end capitalism in order to enact sustainable measures?

Prof. Lenzen: To what extent would we have to upend the current system? To me, one thing is clear: we have to upend the notion of growth because, clearly speaking, the way we’re doing it now, we are able see the adverse effects of growth in just about every way. Global information flows mean that just about every person in every corner of the world knows what the Western notion of luxury and success and happiness is and are striving for this, which is I think a tragedy because traditional systems have a lot going for them. But if this continues, we simply do not have the biodiversity or the idle land or the the water to sustain such unchecked growth.

Perhaps, it can be reframed into the growth of subjective well-being, if you look at Butan. They say that GDP is not a good measure of a country doing well. We’ve known this for a while and there are alternatives, like a “genuine progress indicator” or something. Butan has shown us how a central government can be behind such as such trends.

How much would that impact on a company’s operations? I don’t know, but I could mention that there are ways of producing and maximizing employees’ subjective wellbeing. And how do you do this? Not by giving them more money and letting them work more so they can buy more, but by changing to a business model where decision-making is more inclusive and people have more leisure time. All of these things have been shown to increase the subjective wellbeing. And that, to me, is what it’s all about.

3DPrint.com: I think it’s interesting how you managed to answer that question without saying we do need to upend capitalism. People who are following degrowth are very good linguistically at reframing the conversation in a more palatable way so that people are more willing to accept its conclusions. One thing I did want to go back to is: do you think that technology does have a role to play in getting us under control in terms of emissions and ecological destruction?

Prof. Lenzen: Yes, absolutely. I mean, in the paper on degrowth we’ve written, it is very clearly the message is that degrowth is not something we need to consider instead of technological solutions that we’re embracing now. But because we’ve grown so much and we need to get to net zero emissions by 2050, we need cut emissions by about a seven to eight percent year on year.

Now technological measures would have a very hard time to achieve this on their own, because so far they’ve only ever done two percent year on year. Now they’re being asked to do seven to eight percent year on year—and that is net. If consumption continues to grow three percent and then you achieve a cut of minus seven percent duty, you have technology doing minus 10%. It’s never done this. There’s no evidence that it can do this.

So, of course, we need technology to do that two or more percent and hopefully more in the future year on year. I believe that we need to talk about degrowth as an additional strategy to add to that. Because this portfolio in which we need to achieve a net minus-seven or eight percent year on year decline in emissions, we cannot afford to leave any of the options that we have out of consideration.

In a follow-up article, 3D printing and technology as it relates to the ongoing ecological crisis will be discussed in more depth.