The trouble with net zero

In this episode, environmental social scientist Holly Jean Buck discusses the critique of emissions-focused climate policy that she laid out in her book Ending Fossil Fuels: Why Net Zero Is Not Enough.

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Text transcript:

David Roberts

Over the course of the 2010s, the term “net-zero carbon emissions” migrated from climate science to climate modeling to climate politics. Today, it is ubiquitous in the climate world — hundreds upon hundreds of nations, cities, institutions, businesses, and individuals have pledged to reach net-zero emissions by 2050. No one ever formally decided to make net zero the common target of global climate efforts — it just happened.

The term has become so common that we barely hear it anymore, which is a shame, because there are lots of buried assumptions and value judgments in the net-zero narrative that we are, perhaps unwittingly, accepting when we adopt it.

Holly Jean Buck has a lot to say about that. An environmental social scientist who teaches at the University at Buffalo, Buck has spent years exploring the nuances and limitations of the net-zero framework, leading to a 2021 book — Ending Fossil Fuels: Why Net Zero Is Not Enough — and more recently some new research in Nature Climate Change on residual emissions.

Buck is a perceptive commentator on the social dynamics of climate change and a sharp critic of emissions-focused climate policy, so I'm eager to talk to her about the limitations of net zero, what we know and don't know about how to get there, and what a more satisfying climate narrative might include.

So with no further ado, Holly Jean Buck. Welcome to Volts. Thank you so much for coming.

Holly Jean Buck

Thanks so much for having me.

David Roberts

It's funny. Reading your book really brought it home to me how much net zero had kind of gone from nowhere to worming its way completely into my sort of thinking and dialogue without the middle step of me ever really thinking about it that hard or ever really sort of like exploring it. So let's start with a definition. First of all, a technical definition of what net zero means. And then maybe a little history. Like, where did this come from? It came from nowhere and became ubiquitous, it seemed like, almost overnight. So maybe a little capsule history would be helpful.

Holly Jean Buck

Well, most simply, net zero is a balance between emissions produced and emissions taken out of the atmosphere. So we're all living in a giant accounting problem, which is what we always dreamed of, right? So how did we get there? I think that there's been a few more recent moments. The Paris agreement obviously one of them, because the Paris agreement talks about a balance between anthropogenic emissions by sources and removals by sinks. So that's kind of part of the moment that it had. The other thing was the Special Report on 1.5 degrees by the Intergovernmental Panel on Climate Change, which further showed that this target is only feasible with some negative emissions.

And so I think that was another driver. But the idea of balancing sources and sinks goes back away towards the Kyoto Protocol, towards the inclusion of carbon sinks, and thinking about that sink capacity.

David Roberts

So you say, and we're going to get into the kind of the details of your critique in a minute. But the broad thing you say about net zero is that it's not working. We're not on track for it. And I guess intuitively, people might think, well, you set an ambitious target and if you don't meet that target, it's not the target's fault, right. It's not the target's reason you're failing. So what do you mean exactly when you say net zero is not working?

Holly Jean Buck

Well, I think that people might understandably say, "Hey, we've just started on this journey. It's a mid-century target, let's give it some time, right?" But I do think there's some reasons why it's not going to work. Several reasons. I mean, we have this idea of balancing sources and sinks, but we're not really doing much to specify what those sources are. Are they truly hard to abate or not? We're not pushing the scale up of carbon removal to enhance those sinks, and we don't have a way of matching these emissions and removals yet. Credibly all we have really is the voluntary carbon market.

But I think the main problem here is the frame doesn't specify whether or not we're going to phase out fossil fuels. I think that that's the biggest drawback to this frame.

David Roberts

Well, let's go through those. Let's go through those one at a time, because I think all of those have some interesting nuances and ins and outs. So when we talk about balancing sources and sinks, the way this translates, or I think is supposed to translate the idea, is a country tallies up all of the emissions that it is able to remove and then adds them all up. And then what remains? This kind of stuff, it either can't reduce or is prohibitively expensive to reduce the so called difficult to abate or hard to abate emissions. Those are called its residual emissions, the emissions that it doesn't think it can eliminate.

And the theory here is then you come in with negative emissions, carbon reduction, and you compensate for those residual emissions. So to begin with, the first problem you identify is that it's not super clear what those residual emissions are or where they're coming from, and they're not very well measured. So maybe just explain sort of like, what would you like to see people or countries doing on residual emissions and what are they doing, what's a state of knowledge and measurement of these things?

Holly Jean Buck

So the state right now is extremely fuzzy. And so I'll just back up and say that my colleagues and I looked at these long term strategies that are submitted to the UNFCCC under the Paris Agreement. Basically, each country is invited to submit what its long term strategy is for reaching its climate goals. And so we've read 50 of those.

David Roberts

Goodness.

Holly Jean Buck

Yeah, lots of fun. And they don't have a standard definition of what these residual emissions are, although they refer to them implicitly in many cases. You can see the residual emissions on these graphs that are in these reports.

But we don't have a really clear understanding in most cases where these residual emissions are coming from, how the country is thinking about defining them, what their understanding of what's truly hard to abate is. And I emphasize with this being a challenge, because what's hard to abate changes over time because new technologies come online. So it's hard to say what's going to be hard to abate in 10 or 20 years.

David Roberts

Right.

Holly Jean Buck

But we could get a lot better at specifying this.

David Roberts

And this would just tell us basically without a good sense of residual emissions across the range of countries, we don't have a good sense of how much carbon removal we need. So is there someth