In this week’s episode, host Kristin Hayes talks with Lara Aleluia Reis, a scientist at the RFF-CMCC European Institute on Economics and the Environment, about the extent of progress that’s been made internationally on climate goals that aim to limit global warming to below 2°C. Reis discusses the significance of the Conference of the Parties meetings in Paris and Glasgow (which were held in 2015 and 2021, respectively), how national climate pledges compare with the goals in the Paris Agreement, and how economic models can incorporate and inform climate policy.
Listen to the Podcast
- The Paris Agreement encourages nations to strengthen their climate goals: “In Paris, we started the pledging review process, where countries would voluntarily make their emissions-reduction pledges, and then there would be a stocktake of all of those pledges. After, there would be a review to ask, ‘Were those pledges enough?’ The idea is that, with every stocktake we do, we raise ambition … Every five years, we would commit to new targets, and these targets would become more ambitious.” (4:36)
- Major economies have created global momentum toward achieving net-zero emissions: “It’s true that the [Conference of the Parties] in Glasgow did accelerate this race to net zero, where countries are trying to pledge to see who gets to win the race of net zero. It creates a certain momentum that is important, but it’s also important that we have the contributions from these major emitters and major economies that are creating momentum.” (11:00)
- If fulfilled, national pledges made at the Glasgow conference would limit warming to below 2°C: “In the end, what we found is that we come close to what we would expect. If we look only at temperature, we would find temperatures at the end between 1.6°C and 1.8°C … This is nearly in line with what the International Energy Agency found.” (23:08)
Top of the Stack
- “Glasgow to Paris—The Impact of the Glasgow Commitments for the Paris Climate Agreement” by Lara Aleluia Reis and Massimo Tavoni
- The Last of Us television show
- In the Country of Last Things by Paul Auster
The Full Transcript
Kristin Hayes: Hello, and welcome to Resources Radio, a weekly podcast from Resources for the Future. I’m your host, Kristin Hayes.
My guest today is Lara Aleluia Reis, a scientist at the RFF-CMCC European Institute on Economics and the Environment. Lara has previously joined us on Resources Radio, but, for those who may have missed that prior conversation, here’s a quick reminder on her background: Lara holds multiple advanced engineering degrees, and, as a researcher, she’s particularly interested in climate change, integrated assessment approaches, environmental statistics, energy policy, environmental economics, and air pollution.
Lara is back on the show today to discuss work that she and her colleague, Max Tavoni (who listeners may also recognize as a previous Resources Radio guest), have published on international climate commitments made at the 26th Conference of the Parties (COP26) in Glasgow. The topic of our discussion today is if those pledges will add up to enough to keep warming to under 2°C, if fully implemented. Stay with us.
Hi Lara. Welcome back to the show. Thanks again for joining me to discuss some new research.
Lara Aleluia Reis: I’m happy to be back. Thanks for having me here.
Kristin Hayes: Since we’ve previously asked you to introduce yourself in a professional and personal context, I wanted to start with a different get-to-know-you question this time around. It’s a little whimsical, but I’ll ask anyway: What are your top two or three favorite travel destinations in Europe?
Lara Aleluia Reis: I’m from Portugal, so I’m going to do some shameless publicity for my birth country. The Azores is an amazing archipelagos in the middle of the Atlantic, and it’s a lost place. I think time stops when you go there. It’s beautiful for hikes and ocean views, and it’s an amazing place to get lost. Then, I would say Lisbon. It’s the city where I was born. It’s my favorite city ever, so far. I’ve never been in a capital where the sky is so blue. It’s really blue there, and there’s this breeze there that is really amazing.
Then, I would end up with the Alps. Recently, there was this paper discussing that we have achieved some point of no return on the snowpack in the Alps. I think it is being lost. It’s one of the ultimate European beauties, and it’s going to change. I don’t know—maybe it’ll change to be even more beautiful, but it is already so beautiful that I wish it could stay like that. If you are around, and if you would like to visit, please visit by bike or by walking so that you don’t aggravate the problem even more.
Lately, I’ve been struggling. I’ve been living here for some time now, and I’ve been struggling to find snow for my kids to play with. We live so close to the Alps, and I’ve seen with my own eyes the landscape changing, and it’s irreversibly changing. I hope we can somehow stop that or even reverse it. It’s such a beautiful place. So, I’d recommend the Alps—the French Alps, Italian Alps, Austrian Alps, whatever you like the most.
Kristin Hayes: I’m finding myself wishing we were having a whole podcast just on that conversation. But, we’ll talk about climate change too. We will continue the theme of great travel destinations in Europe, because the work that we’re talking about today is titled “Glasgow to Paris—The Impact of the Glasgow Commitments for the Paris Climate Agreement.” This work was recently published in the journal iScience, and, just as a reminder, both Glasgow and Paris were hosts to relatively recent Conference of the Party meetings that are hosted by the United Nations Framework Convention on Climate Change. These are the big annual meetings where a lot of negotiations happen around international climate commitments. As a foundational question, can you remind us broadly of the timing of those two particular meetings and why they were important?
Lara Aleluia Reis: Paris happened in 2015. It was the COP21. Five years later, Glasgow happened—COP26. In Paris, we started the pledging review process, where countries would voluntarily make their emissions-reduction pledges, and then there would be a stocktake of all of those pledges. After, there would be a review to ask, “Were those pledges enough?” The idea is that, with every stocktake we do, we raise ambition. It’s a very new process. Every five years, we would commit to new targets, and these targets would become more ambitious.
The Paris COP marked that initiation with the Intended Nationally Determined Contribution (INDC). Each country came. In the periods leading up to that meeting, I remember I was already online trying to model those, and there was a rain of INDCs. It started with some 30 INDCs, then 50, and suddenly there were hundreds of INDCs that we needed to review.
It already was clear by then that these were not enough. But the first step toward our ambitions happened in Paris. Another big thing that happened in Paris was that the world agreed that we would need to keep warming levels to well below 2°C and pursue efforts to achieve the target of keeping warming levels below 1.5°C. That’s where 1.5°C gained momentum. In Glasgow, we had a new stocktake, and we saw new commitments and major commitments, especially in the meeting that preceded the COP.
There was a G20 meeting where some of the richest nations in the world got together, and this was maybe also created by some momentum with the new US administration—at the time, the Biden administration had just kicked in. The United States was back in the climate game, and it was pledging net zero by 2050. The European Union had already pledged this, as had Japan and South Korea. We also had other important countries and big emitter nations committing to these targets. We had major economies committing to these targets.
There were other important things that happened at Glasgow. For example, there was a coal-phaseout pledge, and we had more than 40 countries sign on. Unfortunately, China was not in there yet, but some big, coal-dependent countries like Poland did commit to phase out coal. We also had deforestation targets, for example. More than a hundred countries—including Brazil—pledged to reverse or to at least end deforestation. The big elephant in the room that we always talk about with COP is Article Six, which calls for higher-income countries to put money for climate finance on the table so that lower-income countries can finance their own decarbonization. There were also steps at COP26 toward increasing financing. Some countries actually doubled their climate financing efforts. This was also important.
Another important thing came from the latest International Panel on Climate Change (IPCC) assessment report, which was the Sixth Assessment Report. In this report is a methane pledge. We had more than a hundred countries, including the United States, pledge to reduce 30 percent of methane emissions from 2020 levels. This was, of course, before the conflict in Ukraine and Russia emerged. We all have to see to what extent the war will harm these pledges or not, but these were the big differences between Paris and Glasgow. Ambitions were raised between the two COPs.
Kristin Hayes: That’s a great rundown of the types and volume of new pledges that were made at Glasgow, but they seem quite heterogeneous. Some of them are about phaseouts of specific fuels or specific types of emissions reductions. Some of them broadly are pledges around overall emissions levels in certain time frames. Is it fair to say that they are heterogeneous, and how do you think about that heterogeneity as you’re looking to analyze across that whole range of different types of pledges?
Lara Aleluia Reis: They’re heterogeneous, and they also bring uncertainty to the table. If on one hand we know that this is how nations are planning to reduce emissions, not all of the nations are clear on if their pledges are for net zero in the larger sense or just for carbon dioxide.
For example, China was clear that they pledged to be net zero on carbon dioxide by 2060, but India and Russia were not so clear. It’s not clear if they pledged to be climate net zero, which includes all the greenhouse gases, or if the pledges were just for carbon. For some countries, like India and Russia, methane emissions would be hard to abate, because they have other types of sources that are harder to abate.
Countries can play with this level of concept, and there’s some subjectivity involved. It makes it hard for us modelers to put pledges into models, but there is indeed more uncertainty that is being added, especially as we are talking about major economies such as India, China, and Russia.
The other thing is that, of course, these pledges go very far into the future—2050 or 2060 for Saudi Arabia, Russia, and China, and 2070 for India. These are way far in the future. One could eventually say, “What’s going to happen in the meantime?” There is this conflict, and we now have China and India surfing on lower prices that they are getting from Russia. These prices are depleting their carbon budget. The pledges for net zero are very far in the future, and they don’t commit to a certain carbon budget; they commit to reduce by that year. So, we don’t know what they will do until then; this uncertainty is something we would not like to have.
What is important here is not the quantity of countries. Of course, we want everybody to participate for many reasons, but it’s not the same thing if we have five countries pledging net zero and, and these countries include the United States, India, and China; or if we have 100 countries and India, but China and the United States are not there. It’s not just about the number of countries that have pledged net zero. It’s true that the COP in Glasgow did accelerate this race to net zero, where countries are trying to pledge to see who gets to win the race of net zero. It creates a certain momentum that is important, but it’s also important that we have the contributions from these major emitters and major economies that are creating momentum. This is very important.
Kristin Hayes: You mentioned modeling, and I do want to talk a little bit more about that. I appreciate the context that you gave around the levels of uncertainty that are embedded in the task that you and Max took on. You were conducting this research to understand the impact of these net-zero commitments made at Glasgow on overall emissions trajectories. Then, as you mentioned, there are critical temperature scenarios that are consistent with the Paris Agreement, as well. Are the pledges made at Glasgow getting us on emissions trajectories that will be consistent with those temperature scenarios? To do this, you modeled as much as you could in the WITCH model, which was probably featured the last time you were on the podcast, but I wonder if you could remind us of that model’s capabilities, what that model is, what it does, and why it was well suited to the task of trying to understand what these commitments might result in?
Lara Aleluia Reis: The WITCH model is an integrated assessment model. It’s used in contributions to the IPCC Sixth Assessment Report, which is the latest assessment report of the IPCC. One of the main reasons that it was built was to assess the impacts of climate policy. What we do is we try to take stock of all the pledges and energy policy that are going on in the world. This is very difficult, and it adds a lot of uncertainty to the table, because some policies are declared only at a press conference. Some you can find in policy documents; some are probably in language that we are not able to find. You find some information, but it’s not always clear if this is already in law, if it’s just something that is going to be proposed, and so on.
There is uncertainty to this. What we try to do is to collect these pledges and categorize them into more or less reliable pledges, to aggregate them for the regions of the WITCH model. These are macro regions; we have 17 macro regions in the WITCH model for this study. Then, we take stock of everything, and we see which temperature targets we get. We look at both temperature targets and carbon budgets. A carbon budget is the amount of carbon you are allowed to emit. Once you’ve depleted that budget, your emissions need to hit zero.
To look at temperature, we have a reduced-form climate model called MAGICC. MAGICC takes all the emissions from the WITCH model that resulted from pledges and looks at what the temperature increase by the year 2100 might be. One of the features of the model that’s also important is that the model has perfect foresight. For example, it’s able to anticipate investments, because we know that it takes some time for an investment to materialize into technology. The model is able to see that it needs to invest earlier in order to realize emission reductions later. This is one of the important features of the model.
Kristin Hayes: Let’s talk then about the scenarios that you and Max chose to model. I believe you started with a current policy baseline, and I’m going to put “current policy” in quotes, because, as you’ve noted, the level of specificity of current policy is varied and requires some interpretation. Can you talk us through what that current policy baseline includes and how your subsequent modeling scenarios differ from that baseline?
Lara Aleluia Reis: “Current policy” is a great term for study, as well—what would be our benchmark of current policies? What we try to do here is to take stock of all the policies that are out there, especially in 2020, and try to extrapolate those policies into the future. We assume that we will not do worse than these policies. When we extrapolate, we see that these policies are way better than what we used to have as business-as-usual scenarios. There’s a bit of policy in our business-as-usual scenarios. It includes policies that are currently being implemented, and we expect that they will be realized.
We modeled two types of scenarios for Glasgow. You always have to assume that these were the countries that pledged. But, in a limited extreme case, you could also say big economies are reducing emissions by a certain amount, which is an ultimate extreme example. Other countries that didn’t pledge anything could make up for the emissions that bigger economies reduced, and we could be back at the same point. You have to assume that something will happen.
What we do is we look back to the study we did on INDCs, update the INDCs, and we look at what would be the implicit carbon price that they have to have to achieve those emissions goals in 2030. We try to extrapolate that in the future according to how rich a country or region is.
We take income per capita, and effort grows as income per capita grows. This is one of the scenarios. In the other scenarios, we start from effort in 2030, which for some countries may be close to zero. We say, “You’re going to converge to a level of effort that is the average of the whole world or the whole region in the Organisation for Economic Co-operation and Development,” for example. The latter is a more extreme scenario, but it gives us two ways of thinking of a narrative that is plausible; we assume that countries will at least keep up with what they have promised already.
Then we have the Paris scenario, which is the scenario in which we limit warming to well below 2°C with a very high probability. We do that by imposing a carbon budget of a thousand gigatons of carbon dioxide. We do that in a cost-effective way. Let’s say we use a global carbon price. The model decides to reduce where the marginal abatement cost is the lowest and tries to optimize welfare for all the regions at the same time that they are trying to meet their pledges.
These were the scenarios we looked at. They’re different from current policies, because all of them imply either uncoordinated net-zero pledges, which are the Glasgow pledges, or coordinated action that will achieve the ultimate temperature goal by the end of the century.
Kristin Hayes: I’d love to ask you a few follow up questions on those different scenarios. I believe you mentioned that at least one of the scenarios relies on educated guesses on these post-2030 commitments for countries that haven’t made any commitments after 2030. Is that right?
Lara Aleluia Reis: Yes, it’s true.
Kristin Hayes: Okay, great. I just wanted to clarify that. I’m hoping you can say a little bit more about the final scenario that you mentioned and why that was an important counterfactual for you to have in mind. The idea of a global carbon tax and everyone working in harmony does seem like a much less likely policy outcome, but it strikes me that that’s an important modeling baseline for other reasons. Can you say if that is a fair interpretation? If so, can you say a bit more about that?
Lara Aleluia Reis: Yes, I think you can say that it’s a fair interpretation, but it is important to see what would be the most cost-efficient option—at least from a climate point of view. Of course, there are many objectives that we cannot measure; there are environmental problems and other problems that we cannot model.
But it is important to have a reference that we know would be the most cost-efficient or cost-effective way to achieve the 2°C goal. The Glasgow scenario is something else In that scenario, if you want uncoordinated action, every country voluntarily pledges something. In the end, we take stock, and we have a look at whether this is enough or not. We hope that in the next stocktake, countries raise their ambition.
This is good in a way. It’s working, because we see that from Paris to Glasgow, we did have a big increase in ambition, but it is somehow an uncoordinated action. It’s not the most cost-efficient way, but countries may increase their ambitions for other reasons. This is important, for example, for air-pollution reasons or competitiveness reasons.
I didn’t mention it before, but we now have companies making pledges. American Airlines pledged to be net zero by 2050, Coca-Cola by 2040. We have Siemens, General Motors and Ford, which are big car manufacturers, for example, all pledging to be net zero. This gives a sign not only to investors; it creates a movement. It also gives these companies an edge for what’s coming, because it’s not only a climate goal that we have in mind. We are seeing, for example, the carbon border adjustment mechanism in Europe, the Inflation Reduction Act, and all these regional protectionist policies coming into place. This will place these companies that are working toward net zero in a better position than others.
There are reasons that we don’t see behind these pledges that we cannot model, such as competitiveness, for example. In a way, the uncoordinated action may not make sense from a completely cost-effective climate point of view, but it may make sense from other points of view.
Kristin Hayes: That’s a great point. I have asked you many introductory and background questions. I want to make sure I give you plenty of time to talk about the good stuff here—the findings. What does your modeling show about the impact of fully implementing the net-zero pledges made in Glasgow? I want to emphasize that “fully implementing” phrase, because I think that is an important piece of this. It does seem like there is remaining uncertainty about whether countries, companies, and subnational entities will be able to meet their pledges. For this purpose, we’re acting on good faith that this will happen. Is that right?
Lara Aleluia Reis: Of course, we cannot know. We assume these pledges will be fully implemented. We did some sensitivity on this. We have scenarios where you take out the countries we categorized as only announcing pledges for which we have not found a policy document. We do some scenarios where we keep those in or we keep those out, and we see how that matters for temperature.
We also make some assumptions on the availability of direct air capture, which is an important technology, as well as other scenarios for the year at which these pledges converge or the rate at which they converge. We try to do some sensitivity on that so that we account for some of the uncertainties we have on these pledges. In the end, what we found is that we come close to what we would expect. If we look only at temperature, we would find temperatures at the end between 1.6°C and 1.8°C. I would ask to look at this number with caution, because this is just an average value of a single run.
These are 2°C scenarios, more or less, that we are already seeing. This is nearly in line with what the International Energy Agency found. They also found 1.8°C, and also other articles found around the same values of temperature.
This is good news. But when we look at carbon budgets, we are still left with some unabated emissions. If we want to reach those levels of temperature with a high probability—that is, if we want those temperature levels without a lower risk of failing to meet this target, we are left with between 220 to 680 gigatons of carbon dioxide that are still unabated, when we compare these with the optimal Paris scenario that has a thousand gigatons of carbon dioxide in the carbon budget. There’s still some effort there. We did get the raised ambitions that we wanted.
We see that the Glasgow pledges mean around 80 percent of the emissions reductions we would need in 2070. This is not negligible; we are almost there. But there is this little last part that may be the difficult one.
First, we need to make sure that we actually achieve that 80 percent, and then there is this 20 percent left to do. We still need to do it. Let’s see where the next global stocktake takes us. It would be important to know that these pledges are still not enough. I think I’m optimistic, especially since I started working on this 10 years ago and before Paris. We’ve come a long way. Of course, we need to believe that the pledges are met, but if they do, I think we are getting close. We haven’t fully closed the gap, but we are getting closer, which is good news.
Kristin Hayes: Definitely. There are many layers to these results, as well. Can I ask you to highlight another couple of key findings around regional differences. What is the changing energy mix in different places—you mentioned coal phaseouts in certain countries—or some of the pledges that have been made? How does the energy mix change? I know that you are particularly interested in air pollution, too. Is there any information about co-benefits that comes out of this work that you’d want to highlight?
Lara Aleluia Reis: One of the things we should say is that we cannot model all of these objectives. From a climate perspective, this kind of starts to make sense, but they may make sense for other reasons.
For example, we do see higher air-pollution co-benefits in some regions. If we have more ambition and commit in some regions to more effort than the cost-optimal Paris Agreement, we do see more avoided premature deaths. What we also see is these types of pledges—the Glasgow pledges. Although they are uncoordinated action pledges—each country voluntarily comes in and says what they want to reduce or what they will be able to reduce—they mitigate the increase of inequality. What you would normally think with climate policies is that you reduce emissions where the marginal abatement cost is lower. For low-income countries, that means you would reduce emissions in low-income countries, which should be very costly for these countries.
If we have these major emitters and major economies coming ahead and saying, “I will be net zero before the time the cost-effective scenario would actually tell me to be,” this not only lowers the risk of not achieving this target, but it also gives some buffer to the other regions. What we find is that it mitigates inequality amongst these regions, which is important, because major economies are doing more than the effort that they would be requested to do in a cost-optimal scenario.
The other thing that is important to say is that this comes at a higher cost. If it’s not cost-effective, it comes at a higher cost. That’s why I’m saying that there may be other reasons why these regions would be interested in pledging more than what would eventually be needed. But it’s important, because they lower the risk of not achieving these targets.
Kristin Hayes: Let me ask you one more substantive question. We could talk about either travel destinations or climate modeling for a long time, but I did want to flag one piece in your paper that jumped out at me, where you note that one crucial question is to what extent carbon dioxide removal technologies are needed. Why is that a crucial question? What do you find about how much carbon dioxide removal is actually deployed in these different scenarios?
Lara Aleluia Reis: Carbon dioxide removal always brings up a big debate, but it is very important, because it completely changes the costs of your mitigation efforts. When we have big regions pledging to be net zero, there will be some hard sectors to abate, such as cement, steel, and international sectors such as shipping and aviation. In that case, you may use supply-side measures such as carbon dioxide removal instead of demand-reduction measures to abate these remaining emissions. This will lower the cost for some countries. It will not be as heterogeneous, because it’ll depend on the capacity you have to store this carbon dioxide.
These technologies depend on carbon capture and storage, and carbon capture and storage is not yet a fully mature technology. There’s a lot of uncertainty there. But if they were to be mature, what we see is that, because some of these big regions and big emitters are anticipating the year they want to hit net zero, they will have to put these carbon dioxide removal technologies in place in order to reduce their costs or to keep their costs reasonable. One of these technologies is direct air capture.
In that sense, there is a big debate. Should we use these technologies or not? They may, for example, delay decarbonization, but at some point, they may also help us to avoid climate tipping points, other triggering tipping points, and these natural points of no return. These technologies being there can help us to avoid these tipping points. Some say they may delay decarbonization in some countries. There is a big debate and uncertainty on this, and we also did sensitivity on this. The thing that the model is most sensitive about is the cost, of course. Not allowing for direct air capture increases the cost for direct air capture for some regions by a lot.
Kristin Hayes: I encourage folks to take a look at the paper, because there is a lot of interesting information in there. Lara, thank you so much for talking us through it. It’s always a pleasure. Having been on the podcast before, you know the drill for our closing question. I’ll skip the explanation and just ask—what’s on the top of your stack?
Lara Aleluia Reis: I don’t have anything on the top of my stack right now. I’ve been addicted to the series The Last of Us, so I have not been reading at night. But, I do have a book that I want to recommend. This is a book that always comes to me and I always go to read, especially in recent years, first with COVID and now with the conflict here in Europe. This author was on the news for sad reasons, but this is kind of a dystopian book, and we don’t really realize how close we are and somehow how dystopia crosses the line into our realities. I think with COVID and with this conflict in Europe, we see a lot of this. This book is called In the Country of Last Things by Paul Auster.
If you read just the first page, you will immediately see yourself in what the author is saying. This is the introduction of a dystopia, but it is actually happening in our world now. This is the introduction to disaster. When you read just the first page, you have a sense that we are close to crossing the line to the other side of worlds we don’t want and we cannot imagine.
Kristin Hayes: That’s a dramatic way to end. Thanks for those recommendations, and, again, thank you so much for chatting this morning—or, this afternoon in Milan!
Lara Aleluia Reis: Thank you very much.
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