 Good morning, good afternoon, and good evening to all our viewers from around the world. Thank you for joining us today for the Stanford Global Energy Dialogue. Today's dialogue will focus on the topic of atmospheric carbon removal at the gigaton scale. To keep the global average temperature rise below two degrees, we all know that we need massive reductions in CO2 emissions from burning fossil fuels. This is necessary, but not sufficient. We also need to remove atmospheric carbon dioxide at the gigaton scale per year, starting sometime around 2030 and steadily increasing for the rest of the century. What are the best options? How much would they cost? Who will pay for them? How much land would they need? How much carbon free energy would they need? And what R&D is needed? To address these questions, we have a panel of three. Sally Benson is the Precourt Family Professor in the Department of Energy Resources Engineering, and until a month ago, the co-director of the Precourt Institute for Energy with me and the co-host of several previous dialogues. Chris Field is the director of the Stanford Woods Institute for the Environment and the Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies at Stanford University. Ajay Mehta is the general manager of new energy research and technologies at royal.shell. At Stanford, we have started a series of small workshops on this topic, and Sally Chris and I have launched a new seminar course this quarter with very high student interest. We are using this dialogue to share some of our thoughts on this complex topic, which will likely be a topic of discussion and debate for many decades to come. Before we get started, like we often do, let's warm up the audience with the first question. If you add up the weight of all 8 billion human beings on earth, what is the approximate total weight in gigatons? You've got 10 seconds to go. The answer is 7. The gigatons is the most popular answer at 35%. It's actually 0.5 gigatons. So why are we saying why is this relevant? It's relevant because the world emits in comparison 40 gigatons of CO2 per year. If you are to keep the global average temperature rise below two degrees, we have a headroom or a budget of around 800 to 1000 gigatons left, thus leaving us 20 to 25 years before we exceed the headroom. Here we go with quiz number two, hopefully with all the right numbers. In 2018, roughly how much primary energy did the world consume in exajoules? Exajoules is 10 raised to 18 joules. Is it 28? Is it 580? Is it 1275? Or 30 to 50? This is great. 52% said 580. That's in fact is the right answer. Of the 518 exajoules, roughly 85% came from fossil fuels. 195 came from oil, 139 from natural gas, 158 from coal, 40 from hydroelectric, 25 from nuclear, and 23 from renewables. Let's get started. Thank you all for joining us. Sally, let me start with you. The last 150 years has witnessed dramatic improvements in the quality of human life. Use of energy has been a fundamental enabler for this. The prosperity of nations as measured by GDP or GDP per capita is correlated with energy use. Fast forward to 2100. The UN has projected that we will have around 11 billion people in the world, another 3 billion more. If you want a decent quality of life for every human being, how much energy will the world date? Arun, great to see you. Anyway, wonderful question. You talked about a growing population. Clearly, even if we just use the same amount of energy per capita as we're using today, that it would grow by the ratio between 11 and 8 or so. That would grow. The reality is, is that there are many people today who don't have nearly enough energy. About a billion people still don't have access to electricity. Even many of those who do, they either can't afford it or it's of such low quality and reliability that they really can't take advantage of it. So if we were able to get 100 gigajoules per capita, we would need global energy supply in 2100 of about twice what we're using today, about 1100 exajoules. But just to put that in a little bit of context, if everybody in the world used as much as we used in the United States, we would need six times more energy today. But there's really no reason to believe we're going to need that much because if we look at the typical European, they use anywhere say from one third to one half we do. So bottom line is, is I think we can plan on needing about twice global energy supply. That also means that in the development of the OECD countries, it underscores the need for energy efficiency to reduce our energy consumption without sacrificing the quality of life and all the energy services. Is that right? Yeah, absolutely. And there's plenty of room to be more efficient. So let me follow up with this. I know we, I mentioned GDP per capita and GDP. Is GDP the right way to measure human progress and quality of life? Are there better ways to do so? And if so, why? Yeah, well, that's a great question. So GDP per capita is basically calculated by looking at the total gross national product of a country and then dividing that by the number of people. But it doesn't really measure whether it's equitably distributed and it doesn't really matter whether having energy available is leading to other indicators of quality of life, such as human health or education or agency or feeling of support. So the United Nations uses an index called the human development index, which combines education and combines health, indicators, as well as gross national income per capita. And really interestingly, if you look at the human development index and how it changes with access to energy, what we find is once you get to 100 gigajoules per person per year, there's almost no improvement whatsoever in terms of the human development index. So from my perspective, indices such as the human development index called HDI is a much better measure. And they're really exciting new indices coming along that also measure other factors like how empowered people feel to improve their life or how much support they feel they get from their society. So just to follow up on that, that's for the human side. Are there similar measures for the environmental side for the planet? Well, well, you know, that is that is a great, great question. You know, I'm not familiar with one, Chris Spield, who has got on this call maybe. I think I certainly think we need one because obviously there are multiple factors affecting the planet, losses in biodiversity, changes in air quality. So there are many water scarcity, changing impacts from climate. So yes, it would be wonderful to have an index that would capture the global state of health. There has been a lot of work in developing a gross ecosystem product that's the parallel of GDP, but one that acknowledges the value added to economies and to people's lives by ecosystem characteristics. And it's being developed primarily by the natural capital project at Stanford and being deployed increasingly around the world and is under the spotlight, I'd say by organizations like the World Bank, what really want to have a good insight into the full range of implications of our development pathway for the ecosystems, for the people, for the economies. So to follow up, Chris on this, just the scale of energy that is needed that Sally just talked about, it seems likely that there'll be many gigatons of greenhouse gas emissions in the next few decades that'll happen. What happens, tell us, tell the audience, what happens when we inject CO2 in the atmosphere? How long does it remain in circulation? Why is removal of atmospheric carbon so important? The simple reason that removal of CO2 is an important issue is that warming from carbon dioxide that's injected into the atmosphere is essentially permanent, at least on a scale of thousands of years. I think we all would like to believe that the solution to climate change, to restoring something less than they are now, is to simply stop emissions. But that doesn't work. That stabilizes temperatures at more or less the level they are within a few decades when we stop emissions. The reason that the warming from CO2 is essentially permanent has two components. One is that CO2 lasts a long time in the atmosphere and about 20% of any CO2 we inject in the atmosphere is still there a thousand years from now. But an even more important factor is that currently the amount of heat that's left in the atmosphere is a strong function of how much of the heat goes in the ocean and most people know that historically, with climate change to date, more than 90% of the extra heat is in the oceans and the ability of the oceans to take up this extra heat has a lot of leverage on how much of the energy is left in the atmosphere. Over time, CO2 gradually dissolves in the oceans as the oceans turn over and they essentially bring historic water up to the surface. But that same process that is allowing the oceans to essentially get filled up with whatever the CO2 level in the atmosphere is, also was allowing it to get filled up with heat. The oceans get to be less and less effective at taking up a fraction of the heat from the atmosphere, leaving more in the atmosphere. So the function of those two things together is it makes warming from CO2 essentially permanent. That means if we want to prevent future emissions from heating the atmosphere or if we want to cool the atmosphere, the only option is to remove CO2 and to amplify the natural processes that historically have removed some fraction, and we need to do better than that if we actually want to manage climate change in a way that produces temperatures. So what you're saying is that it's not just a matter of scale, magnitude, it's also a matter of rate because we are emitting at a rate which is much faster than what the natural system can handle and thereby we need to increase the rate of removal more than the natural rates. Did I get that right? You know a way to think about the natural carbon cycle is that in general it's it has operated very close to equilibrium. There's a large amount of uptake every year from plant growth and there's a large amount of release every year from decomposition. And to a first approximation those are historically balanced. The entire magnitude of the imbalance in atmospheric greenhouse gases is a result of human actions, the combustion of fossil fuels, and the clearing of forests. And so when we talk about solving climate change the natural cycles aren't going to do very much to help us because they tend to operate so much in close to equilibrium. We can take advantage of a set of technologies that we call natural climate solutions to amplify the effectiveness of the natural side of the cycles but the core responsibility for addressing the problem has to focus on the human emissions. It's also important for people to remember that we're already receiving what you might think of as a giant subsidy from nature for our CO2 emissions over the last several decades of every ton of CO2 that's emitted to the atmosphere from fossil fuel combustion. Almost 30% is currently taken up by ecosystems on land and remaining about 25% is dissolved into the ocean. So only about 45% currently stays in the atmosphere and if we want to address climate change what we need to do is deploy an additional family of technologies so that the part that stays in the atmosphere is even less than that 45%. So let me switch to Ajay who as you heard is from Shell. Ajay why is an energy business such as Shell interested in atmospheric carbon removal? Great thanks Arun and really delighted to be here. Let me try to answer that question by kind of framing it first kind of under the broader strategic ambition that we have at Shell. As Sally mentioned you know we're looking at a doubling of the energy system over the next several decades so one of the strategic ambitions that we have as a company of course is how do we maintain our investment case to be a world-class investment case which means that everything that we do in our conventional business which is not going to be going away anytime soon because we're going to continue to have to provide energy to the world needs. How do we ensure that that is operating at top quartile so we continue to have the cash to be able to even think about how the energy system of the future is going to evolve and what role we could play in that. The second thing is that we are not afraid of the energy transition we actually want to thrive in it. We just need to figure out what is the most relevant part of the energy system that's going to evolve where we can play the most critical role in there and the third piece is around the societal license to operate you know there is a tremendous you know push from various segments of society which are beginning to understand that the issue of climate change is real and Shell has you know accepted the role of global warming and the need to keep temperatures less than two degrees C for many decades and as you know a couple of years ago we had also come up with a scenario called the Shell sky scenario that looked like that looked at a world where we want to get to net zero emissions over the next you know 40 to 50 years and the question was is this technologically and economically possible and our answer to that was absolutely it is it's what's lacking there is the will to be able to do that and how do you put in the public private you know partnerships to be able to get there and there are a number of ways you know in which we will go about to achieve that ambition and certainly that means you know a massive further penetration of renewables it means you know we're going to also see the net carbon footprint that needs to go down substantially from our existing businesses but we have also gone a step further where we've kind of said that we have an ambition to become a net zero business by 2050 and if you're going to become a net zero business by 2050 it's not just about the emissions that come from your production and your operations but it's also from the end use of the products that our customers use so I think even the first company in 2017 to go out and say that when we talk about net carbon footprint it includes the emissions of the end use of the products and the only way that you can get to a net zero business is by thinking about technologies like what Sally and Chris have mentioned which includes net negative emission technologies and so that's kind of you know a big driver for us when we think about this much more holistically of achieving both you know the climate change ambitions as well as getting to a net zero emission business. Thanks Ajay so now that we have set the stage for the dual challenge of needing more energy in the future as well as the need for atmospheric carbon removal let me switch to Chris now and let's go a little deeper. The word of atmospheric carbon removal can be divided into two interlinked categories. One is natural climate solutions that harnesses the natural cycles of CO2 and the other is engineered or hybrid solutions. There is a paper that came out in 2017 in the proceedings of the National Academy of Sciences led by Bronson, Griscombe and 31 other authors that laid out all the options for natural climate solutions. So Chris give us an idea of the most promising options and the likely challenges that it will face. Sure well Arun the critical starting point is that plants and trees and grasses and shrubs and crops are a wonderful advanced technology for CO2 uptake. The process of photosynthesis using energy from the sun to fix atmospheric CO2 and to carbohydrate more plant is something that evolution has been working on for more than a billion years, works efficiently and in contrast to all of the engineered technologies the infrastructure for photosynthesis is self-assembly. You plant a seed and it grows into a plant and a bunch of plants grow into a forest without need for a large amounts of human intervention. That means that photosynthesis can operate at very low cost relative to the engineered solutions but the challenge with any of the solutions that depend on photosynthesis plant growth to remove CO2 from the atmosphere they take large amounts of land area and they take large amounts of water and nutrients that things that everybody understands you need in order to grow plants. So in order to take full advantage of these natural climate solutions basically what we need to do is increase the ratio of uptake of atmospheric CO2 by photosynthesis relative to the loss from harvesting and wildfires and decompositions and Griscombe and his colleagues looked at every place in the world where we have the opportunity to you could think about as doing a better job of managing ecosystems and they came up with a maximum potential kind of independent of cost but focusing on all the areas that we don't need for food protection, food production or for urban areas or other necessary land uses. It came up with a really big number they argued that we could in principle deploy photosynthesis based or natural climate solutions for about 23 billion tons of CO2 per year. About half of current emissions and more impressively they calculated that if we had a hundred dollars a ton that we could spend on deploying these solutions we might still get a little bit better than 10 billion tons of CO2 per year. So a really substantial amount of the carbon problem could be managed through these natural climate solutions if we're willing to make the kind of commitment that's represented by a hundred dollars a ton carbon price. So I was when reading the paper I was struck by the fact that the lowest hanging fruit in terms of scale and low cost on the order of you know less than 100 or maybe tens of dollars of ton is the increase in food productivity. What is the deeper connection between food and carbon removal and you know the follow-up to that would be you know there's a lot of interest in this plant-based diet and things like impossible foods and beyond meat. Do they make sense and if so at what scale should they be? Well a striking feature of our greenhouse gas budget overall is that about a quarter of greenhouse gas forcing of climate comes from food agriculture and other land use. Some of that is methane from cattle and wetlands. Some of it is nitrous oxide from fertilizer management and quite a lot is still from deforestation which is occurring especially in the tropics. So there's a definitely a big footprint of a specially meat-based agriculture a forcing of climate change and any decrease in preference for meat could make a real difference in that. When we think about natural climate solutions that are related to agriculture there are really two kinds of solutions that look like they make a lot of sense. One is changing agriculture so that it can store more carbon in the agricultural fields and doing a better job with soils and no-till agriculture is an example of a way to increase the organic matter in soils. But an even more powerful set of approaches is what you have implied Arun at an involves increasing the productivity of our existing ag estate so that we don't need so much land and can return some of that land to forest and other natural ecosystems that have the potential to store dramatically more carbon. And this is a very tricky challenge. We've already spoken about the expected increase in human population and the expected increase in food that that is going to entail. But at the same time we're have had a history of dramatic successes in increasing the productivity of our agriculture lands and I think a realistic but ambitious goal for the future is to be able to meet the food needs of the of the growing human population without increasing the amount of land that's used for agriculture. Personally I'll be surprised if we can dramatically decrease the amount of land we need to use for agriculture unless there's a societal shift in the preference for meat and it's intriguing to see the popularity of the meat alternatives like impossible and beyond meat and it also it will be intriguing to see if in the future as societies get to be more and more wealthy the the demand for meat-based diets continues to increase. I think that if we were to say what's the what's the cheapest healthiest step that we could all take in order to address climate change shifting that dietary preferences way high on the list. So so Chris what you're saying is that we need sort of using a historical analog we need another green revolution of the form of Norman Burlog that happened in the 1960s. In addition a change of diet to its plant base would be the combination of that could be very powerful. Go ahead. Well I was just going to say that the queen revolution has been totally transformative in providing sufficient calories to meet the world's needs and we we will be doing all we can if we can sustain the kind of productivity increases the one to two percent year on year increases in ag outputs that we've seen over the last half century a major challenge for the future is figuring out how to sustain those productivity increases especially in the context of a changing climate that in many cases is making habitats less suitable for reliable food production. Just to the audience I know that a lot of questions about that reference for the paper I will put that when the student section comes on but I just want to move on to another question for Chris. There is more carbon in the soil than in the atmosphere and oceans combined you can correct me if I'm wrong. We are living in the golden age of biology with gene editing tools that are being not only developed but applied to agriculture. Couldn't we use modern biotechnology to not only increase food productivity but also put more carbon in the soil by for example deeper roots with higher lignin content. So tell us a little bit about soil and what are the uncertainties about soil do we really understand them and is that a viable option going into going on the future. Yeah let me let me just say one thing there's way more carbon in the oceans and there is in soil um several orders of magnitude more carbon in the oceans and when we talk about the historical carbon cycle the the big big players are of course the ocean and and the amount of carbon that's in rocks but it is it is in fact true that there's substantially more carbon in soils than there is in either the atmosphere or in above ground plants and and we don't usually think about the soils as the big player in the carbon cycle. The reason for that is that the turnover of soil agatic matter tends to be quite slow it's on typically on a scale of of several centuries but there's been a huge amount of interest in some of it at the stage of speculation but some at the stage of real experimentation that if we could simply increase the fraction of current primary production that that stays in the soil on a year by year basis by a by a fraction of a percent it could make a big difference in building climate solutions in in removing CO2 from the atmosphere and the there are a whole bunch of kinds of steps we can take one of the the most attractive features of steps to increase soil carbon is that they also tend to increase soil fertility and provide the kind of win win that we look for especially in natural climate solutions so steps like decrease tillage growing crops that have higher yields potentially genetically engineering crops so that they're less susceptible to that the residues are less susceptible to decomposition that the important thing to remember about soil organic matter is that it's not mostly about the stabilization of dead plants it's about a huge biome of microorganisms bacteria fungi and that when we talk about soil organic matter it's usually the the the bodies of these fungi and bacteria that are the the bulk of the material and then their waste products and so we can't just turn a switch and say okay we're going to make different plants and they'll stay in the soil much longer but we are beginning to get enough of an understanding of the richness of this below ground ecosystem that we can begin to start tweaking it my my personal sense is that even though we should be putting a lot of attention on asking what could be done there the the fact that soil carbon pools tend to go up and down relatively slowly means it's going to be hard to get high rates of flux into soils on the global scale so when you step back from all the complexities and the opportunity in national climate solution is that sufficient to address atmospheric carbon removal at the scale that we need or what are you I mean are you optimistic are you pessimistic well what are the uncertainties yeah so let me say that probably the most important natural climate solution that we have access to that we haven't spoken about today is is slowing and then stopping the cutting of forests especially tropical forests and there are tremendous benefits in terms of habitat biodiversity air and water quality that can come from slowing tropical deforestation and in many cases the financial resources that are necessary to do that are not all that great especially if they're coupled with political will as we saw for example in brazil in the early years after 2000 but still if you add up everything that we can expect to accomplish with natural climate solutions even with the abundant co-benefits that we expect to be able to obtain we'll still only be taking a slice of the overall climate challenge and and a slice probably less than a quarter of the total amount of co2 removal that we'll want to do during the 21st century so as is the case with almost everything in climate change we need to look at a portfolio of natural climate solutions as part of a broader portfolio of co2 removal technologies which are only part of the portfolio of climate change solutions thank you chris let me move to sally now and um this is a good way to transition to hybrid solutions and both sally both you and chris have collaborated on bioenergy with carbon capture and storage becks describe what it is and why does it seem promising and are there any rnd or infrastructure challenges that are that are relevant for this technology okay terrific yeah so you mentioned this is a hybrid solution becks bioenergy plus ccs and when we say it's a hybrid solution what we mean is that we're using nature to capture carbon dioxide from the atmosphere by growing trees or growing grasses or or agricultural crops where we can use the residues we can then harvest those that biomass and we can use it to generate power much like you would have a coal plant you can burn the biomass after you burn the biomass and produce electricity for example or heat for industrial applications you can put on a chemical scrubber that will separate the carbon dioxide from the from the flue gas you can then take that captured gas and you can pump it back deep underground you could put it into an oil reservoir gas reservoir or you could just put it into a geologic formation that was filled with salty water and that it would retain it and the idea behind geological storage is that it's essentially permanent storage of the carbon because you put it so deep under the ground surface and you've put it into a formation that effectively traps it so it will remain there forever so so that's the the basic idea of the technology you know this is something that we could do today all of the components are known you know we we know how to you know grow grow and harvest crops we know how to burn them we know how to capture carbon we know how to store it underground so I mean said that though that's not to say there aren't challenges for example and that is for example how do you affection effectively and efficiently get all this biomass and transport it to a someplace where you could put it into the facility to convert it to energy biomass has very low density energy density so that transportation can be quite a challenge so so we've taken a look in the United States and around the world at what is the potential for biomass energy plus CCS and in particular in the US we took a look at what if you just took all the ag residues and forest residues and waste and if you use that for bioenergy plus CCS what would be the potential there and it turns out in the US today it's almost 400 million tons per year so that's quite substantial however we then said well what about is it co-located with a good storage site or not and we found that when we apply that screen we end up with about 100 million tons per year which is significant that represents all by itself represents about 25 percent of the total contribution of CCS that we may need in the United States to to meet our decarbonization goals if you look out to 2040 where you start having dedicated energy crops that get number gets significantly higher you could you know imagine getting into the half a half a gigaton per year so so very substantial so in terms of the challenges I think it's a challenge of scale most bioenergy plants are quite small they're on the scale of you know 50 or 25 to 50 megawatts per per year we would like plants on the scale of a gigawatt per year like a big coal plant then we can be very efficient in the capture and storage of this process so so there's you know usually we're thinking about upscaling but you know can we downscale all these processes could we actually efficiently and economically run these a very small scale I think that's an issue you know and at the end of the day if we're evolving to using bio bioenergy crops all the trade-offs that Chris has mentioned between land use for food land use for ecosystem preservation and all the other services those are very serious issues that need to be addressed so if we decide to go forward with this in a very large way we're going to have to clearly understand the impact of any incentives we might create on on land use because we certainly wouldn't want the the unintended consequence of greater conversion of wild lands for example for this use when those wild lands are already providing very valuable services either system services up and quickly with a just a way to think about it when we talk about ambitious deployment of BEX sort of at the scale that makes it have a big dent you know addresses something like a quarter of current emissions we're really talking about a land area of dedicated biomass energy crops that would be comparable to the land area we're currently using for all crops so potentially doubling the scale of agriculture if that's the direction we wanted to go and there are as Sally says serious questions about whether we have that much extra land available so moving on to the next topic Sally and before that we're going to have a quiz so this is the third and the last quiz there is a lot of excitement about direct air capture to capture one ton of CO2 from the atmosphere using DAC roughly how much energy in gigajoules is required by today's best approaches 0.07 0.7 7 or 70 7 gigajoules that is in fact the most popular answer that is the right answer according to the laws of nature thermodynamics the minimum energy required to capture CO2 at 400 ppm or something million is about half a giga joule today's systems operate at 7 gigajoules per ton of CO2 almost 90 percent of which is heat so to capture a giga ton of CO2 a giga ton of CO2 we will need 7 exajoules of emissions carbon emissions free energy so Sally does direct air capture make sense to you if so what are the r&d challenges what are the scalability and infrastructure challenges are there more cost effective and scalable approaches okay great question so so direct air capture is really exactly what it sounds like is that you'd have essentially a large machine that would take air it would move through air through that machine you'd have some kind of chemical scrubbers inside that machine that would take the carbon dioxide out of the air and then you could again store it underground for example so that's the idea of direct air capture in principle it's very similar to capture from concentrated emission sources like power plants or cement plants or steel plants because again it's basically a chemical scrubbing technology the challenge however is that if we think about air we've got about 0.04 percent CO2 molecules in in the air okay so it's not very much so it's very very dilute in the atmosphere even though it's building up it's still very dilute and just to put that in perspective a coal plant will be about 12% CO2 a natural gas plant will be about 4% CO2 cement maybe 30% so so you can see this 0.04% is is a challenge and that um is very low concentration okay so what's the issue with that well number one is that the more dilute a source the fundamentally more energy it takes to capture it so if we compare for example capturing CO2 from air to capturing CO2 from a coal plant it's the very best we could do is would take three times more energy and we already know that capturing CO2 from a coal plant you know takes about say 20% of the energy that would otherwise be used to produce electricity so so it's significant and now we're saying okay well we need to triple that you can see right away that that's a challenge the other challenge is that what we know from experience is the more dilute the source that we're trying to capture from the less efficient the process is overall okay it's just harder and harder to make efficient you need much bigger equipment and so forth so you take those two things together the fundamental thermodynamic limits and and and the fact that you have less efficient processes at least from my perspective I say as long as we've got concentrated sources of CO2 I think it's preferable to go after those now having said this that you know which one would say well why would we do this now it may very well be in the long run we're going to need to use direct air capture to take the CO2 out of the air and really the competition are these natural climate solutions that Chris talked about and it turns out that if you look at a plot of land if you look at say an acre of land actually direct air capture is quite efficient for removing removing carbon dioxide relative to what what an ecosystem may be able to do and again you can do it year in year out and so forth and and then the other benefit is if you use direct air capture and you have the CO2 and you put it underground you can be very confident that it's not going to come back out you know if you put it again like a mile or a kilometer but beneath the ground surface so there's a real benefit in terms of permanence if you've captured from air and stored it stored a deep underground. So I'm going to come to Ajay soon but before I go there Sally say a little bit about other engineer techniques you know there's there are ideas of seeding the ocean with iron to create an algal boom a bloom that are weatherization of rocks how effective cost effective are these how scalable what are the risks involved do we really want to mess with the oceans or is that safe I don't know tell me yeah well you you know you're getting definitely from the sort of tried and true you know bags direct air capture natural climate solutions we know a lot about so as we're moving into some of these other solutions and you you mentioned two one is a technology called ocean fertilization and the second one is mineralization we actually know much much less about those but to say first a little bit about ocean fertilization so if you look at oceans around the world what you can find is that there are critical nutrients that limit the biologic productivity of the ocean and it was actually fascinating in part they discovered this because they would look when there would be a big dust cloud that would come from Asia for example over the Pacific and they would look at the ocean underneath these dust clouds they would find this enormous bloom of biological activity and gradually they connected the dots and they they figured out that iron was actually this rate limiting nutrient and then these blooms were in part due to the fact that the dust provided iron to to the ocean so their interest grew in this trying to make this an engineered solution so there have been a number of experiments in the southern ocean particularly which is a very appealing place to do this and indeed if you put iron in the ocean you will get a big bloom of biological activity which of course it takes carbon dioxide out of the out of the ocean and then the ocean can absorb more from the atmosphere so that part is known the question though is what is the fate of that that that that co2 and and ideally what you'd like is to rain down to the bottom of the ocean and be deposited you know in an organic matter on the floor but what is known is actually that there's a tremendous amount of cycling that takes place in the near-surface ocean so that how much of that bloom of organic matter actually ends up being exported and really creating efficient removal is very uncertain and it turns out it's very complicated it depends on a lot of things like is it stormy weather is it is the other issue with that is if you have this massive bloom of of biologic collectivity you can actually run the risk of creating anoxic zones in the ocean so now you've got a school of fish they're swimming into this region and you know then that's very potentially nutrient depleted and and you know would there be effects but i think that the the bottom line is there just many many uncertainties about that so just briefly on another technology you mentioned is the idea that you would take minerals so it turns out that magnesium silicates is a good example rocks like olivine that if you expose them to the atmosphere they're going to react with a carbon dioxide and they're going to make a magnesium carbonate for example and this is this process is as old as geologic history actually it's called weathering it's a very well known process so so the idea is well if you could take these rocks and you could crush them up so they had a high enough surface area and you could put them where they would be exposed to the atmosphere we know that they will take carbon dioxide out and they'll convert it to rocks that are very stable so that's an interesting idea there are challenges though you have to mine all of these magnesium silicate rocks you need to grind them to a pretty fine size so you have enough surface area so they're going to react quickly and and and exactly how fast this will take place and how the rate of reaction depends on the physical environment where they're located these again are many uncertainties so I think there's a very very interesting area there have been discussions about putting these materials into into into agricultural settings which may actually also provide some other nutrients or soil benefits so I think it's really early days for for those technologies and I think we need more research and and it's beginning to happen thanks Ali let me now move to Ajay you've heard all the options the challenges the uncertainties and opportunities on the natural climate solutions on the hybrid solutions as well as the director capture or other engineered solutions and this there are options that okay now apply a business filter to this and tell us why this is important to you what do you see in this what's the time scale what's the magnitude what are the investments that are needed when would that happen so tell us the business perspective great no thanks thanks Arun and really interesting to hear Chris and Sally just talk about you know what are the both the technology pieces as well as kind of the underlying issues and challenges associated with making it happen I'd like to kind of tide back to kind of you know the whole title of this session which is around gigaton scale so for us scale is perhaps the number one issue that we look at so when we talk about BEX for instance then the bioenergy part for the feedstock is one part of the equation the CCS part is the second bigger part of the equation and I think that is kind of where there's a lot of interest and attention being paid we are very active in a number of CCS projects around the world but you have to kind of step back and take a look at why isn't CCS more prolific than what we currently have that's what less than 40 million tons a year of carbon that is currently being captured in various projects around the world if you think about that sky scenario the two-degree sea world of getting to net zero in the next 50 years then we are projecting that you need 10,000 projects of about a million tons per annum you know so that's kind of the size of a project that we have in Canada called quest where for the last four years now we have been sequestering CO2 and so that just kind of put I throw that number out just to put our arms around this the scale of the problem we are talking about potentially needing one quest like project that needs to be commissioned pretty much every 15 days for the next 30 years so when we think about these types of options that's kind of the lens that through we look at it that how do we practically get to that point where we can start doing stuff and stop talking about it theoretically a lot of things are possible but how do you get to the implementation phase of these projects the other part that Sally talked about with direct air capture is a very intriguing problem for us in the industry because I think if you think about it from the point of view of would you do everything all the negative emissions that you need to you know get to would all of that come from direct air capture and that's a non starter however does direct air capture have a role to play as a building block towards creating synthetic fields so that's another area that's of keen interest currently in the industry when you talk about sustainable aviation fields so for example there's a pretty strong appetite from the aviation industry to see what would it take to get to a so-called green fuel and one of the things that's been getting a lot of excitement and attention you know internally inside Shell as well as a lot of other places globally and academic institutions as well is this whole concept around power to liquids you know if we truly believe that with the penetration of renewables continuing at the pace at which it is continuing then is the world in which we can assume that we can get to 1 to 2 cents a kilowatt hour generally ubiquitously you know a condition that can be fulfilled if so then can we actually think about you know generating hydrogen at scale through kind of large-scale electrolysis so you can generate green hydrogen and then can you use techniques like direct air capture to capture CO2 from the atmosphere and once you have your feedstocks of hydrogen and CO2 together you can synthesize a molecule of interest including an aviation fuel for instance so it's like how big of a market is that going to be it's a pretty huge market when you think about you know the fact that I don't believe for any time to come people are going to stop flying and also I don't believe the era where hydrogen powered air travel or battery powered air travel is imminent so when you think about it from that lens then again it ties back to this whole concept of negative emission technologies because you can think about you know coming up with more efficient means of making your jet fuel or a slow conversion to low carbon fuels for the aviation sector to just you know stay with that example you can think about what is the energy source that is used the so-called indirect emissions the so-called the scope to emissions to make that aviation fuel but then thirdly when you do accept that you will have liquid hydrocarbons if you can make it through a synthetic pathway that's fantastic but you know for the interim period where you are still continuing to use you know non-synthetic fuel then how do you offset the emissions that still come from the burning of that fuel and again that's where you know the natural climate solutions piece again comes together so I just offer that as an example to kind of think about how does a business think about it you know we are not trying to say that there's one silver bullet we have to do all of that but it has a very significant role in kind of how the whole energy system in the future will transform so if there is one or maybe two government signals predictable long-term signals that a business like Shell would need tell us what those are yeah I think the one thing that the business wants is some sort of price certainty so you know so we have been kind of very strong advocates for a long time around carbon pricing you know so agnostic at this point about what kind of mechanism that might be whether it be a cap and trade or a carbon tax but there needs to be a carbon price signal and that can really trigger a bunch of other products to actually get into the marketplace that that's one aspect another aspect I'd say is is policy frameworks around measurement and monitoring you know that's another very significant piece of the puzzle whether you're thinking about methane emissions or CO2 emissions or in fact you're talking about natural climate solutions because one of the things that Chris talked about is around forestation and a forestation and carbon credits that you could get as a consequence of that the only way that these will be considered to be credible offsets if there is a mechanism you know by which you can validate you know that how if you're going to be capturing CO2 and claiming a credit for it that there is a means to say that yes this is a viable credit for the next 30 50 years so putting in some sort of a mechanism guidelines to be able to do that and a framework to be able to do that those I think would be two very powerful signals so that would come from a policy perspective. Thank you Ajay. Now let's start the student section for the dialogue let me introduce E.J. Bake who is a PhD student in the Department of Energy Resources of Engineering incidentally she is also the lead author of the P&AS paper on BEX that that she co-authored with with Chris and Sally so let me bring let's bring E.J. let's welcome E.J. to the stage. Hi Arun thank you very much for inviting me to be here today thank you for the panelists for what's been a great discussion so far I really look forward to sharing some questions from our students here at Stanford today so the first question is for you Ajay and it kind of kind of builds upon the the discussion you are having with Arun just now but who really pays for atmospheric carbon removal and why and in thinking about Shell's plan to become a net zero company by 2050 could you briefly go over the role of private sector and public sector money in both catalyzing action but also sustaining what will be a potentially enormous industry as you mentioned will atmospheric carbon removal will be considered a public good at some point we'd love to hear thoughts. Thanks that's a great question E.J. I think my short answer to your question would be that it is going to require both it's going to require both public and private companies to work hand in glove together Shell is very actively thinking about you know what types of investments does it need to be need to make over the course of the next 20 30 years as we you know aspire to become a net zero business but that means that we also have to fundamentally rethink not only just the product mix and the product you know a suite that we offer to our customers but also we need to be thinking about how do we enable our customers also to decarbonize so you can only become a net zero business if the customers to whom you are selling your products are also equally invested in making their products a net zero so when we think about our own ambition then what we recently said is that doing everything that we are you know wanting to do we have a very aggressive target of reducing our net carbon footprint by 65 percent by 2050 that's not going to get us to be a net zero business what'll allow us to get to a net zero business is then if those products are also by the end customers you know also certified to be net zero products and so that's going to change the mix of also who are going to be the customers of the future because you eventually want to get to a point where even where you're even selling your products to customers who are philosophically aligned with kind of where you want to go you know as a company so that's kind of one aspect to your question I believe that there will continue to be a need in many areas as we want to increase the rate at which we have a penetration of renewable energy technologies or negative emission technologies for government to play a role to incentivize you know deeper penetration of these so there are certain schemes of course that you're familiar with you know whether it be the 45q to incentivize ccs you know ccus applications I also believe that in the case of hydrogen for the next 10 to 15 years as hydrants beginning to get a lot more center stage it's going to continue to need a nudge from you know from the government to say yes this is something that is interesting they're going to have to work together to build an infrastructure to make this vision come to fruition but I don't believe that this is something that's going to have to last forever you take a look at what's happening in europe with offshore wind yes the first revolution was kind of you know incentivized with subsidies and the like but all the auction sales that are taking place right now are subsidy free so I think it's kind of a you know it's not an easy answer to the question it's kind of you know it requires both parties to gel together you know everything from large government as well as to the retail customer you know with nature-based solutions for example we have a program going on in UK and the Netherlands at the present time and it's going to go to other parts of europe and the rest of the world soon where you know as you go to the gas station to fill up gasoline you can pay an extra penny per liter which is then used to offset you know all the emissions that might be caused by the end use of that fuel so I think there's kind of depending upon the scope and scale of the problem there are there's different answers to that question but it is eventually going to require both parties to work very very closely together thank you Ajay that was great the next question is actually kind of building up on some things you mentioned Ajay is for Sally what do you think needs to change for the near term deployment of atmospheric carbon removal you know there was some mention of you know subsidies and technology costs and you know California is a great example where there is currently almost a $200 per ton of low carbon fuel standard credits and perhaps almost $50 per ton in 45q credits that can be gone provided for atmospheric carbon removal technologies and so you know what else might we need to really spur the development in the near term valley great question thanks you know I think that direct air capture is you know really in its early days so what we need now are some demonstration projects at scale and you mentioned in California the low carbon fuel standard which is now valued at about $200 a ton as long as your offsetting for example transportation related emissions which you know and that's getting to be at the level where this may actually be affordable I mean exactly what this cost people don't know you know in time it's believed that it could get down to maybe $150 a ton or so so their $200 would be very attractive but right now it will probably be more than that but but I think a demonstration at scale would be very very helpful but it turns out if you are for example using direct air capture and your goal is to offset emissions you need to sequester it right you can't just have a carbon neutral cycle that that would really count in terms of it being being a removal so there are a lot of institutional issues that remain unresolved for example if you decide the store CO2 underground you know who owns the pore space it's generally believed that the surface surface owner will have the rights to those pore space and and one would need to negotiate and access agreements or lease with them but that's not fully codified so that would be very helpful it's also turns out that in many cases there's a regulatory multiple regulatory jurisdictions which would oversee some of these projects and you know and that will probably always be the case but in the very early days where you're doing first of a kind project if it takes you years and years to get all the permits you need to to transport the CO2 and to uh injected underground it could be a huge disincentive because we don't want to wait years and years so so some kind of a public-private partnership that wouldn't bypass any of the rules but it would just expedite the execution on on all of the regulatory issues though those those things would be extremely helpful so I think you know large-scale demonstrations will be the really the next critical step in evaluating this technology and seeing what will be necessary for it to get to scale. Thank you Sally that was great this is the last question from the student section and it's for Chris so New York passed one of the most ambitious climate goals in the US yet and that was to reach a net zero economy by 2050 but interestingly New York chose to go with 85% direct emissions reductions and 15% emissions reductions to be satisfied with carbon removal technologies such as negative emissions or direct air capture so based on this policy measure how should we think about the appropriate proportion of direct reductions versus negative emissions you know is there a risk of relying too much on negative emissions technologies in the future and if so how how large is that risk? Really good question we're in an era now where we can't specify with a high level of confidence what the proportional contribution of each technology to eventual decarbonization will be and I think that you've heard compelling calls from from Sally and Ajay for active experimentation to explore each of the technologies see what kind of potential there is see what kinds of unexpected limitations there might be. There is a deep risk with all of the carbon removal technologies that we've not yet spoken about and it's a risk that it provides a potentially false hope that we can solve this problem by working harder on late carbon removal later in the in the century but we can continue to have rapid utilization of fossil fuels in the near term because in the long term we will turn a switch and all of these direct air capture becks natural climate solutions will come into their own and essentially solve the problem and I think we really need to work very very hard to assure that that can kicking ethic doesn't take over in this space if we want to solve the climate challenge we need to be working as hard as we can now on each of the technologies including direct emissions reduction and utilization of CO2 removal technologies the idea that the eventual mix might look something like you know 85 emissions reductions 15 percent CO2 capture it doesn't that doesn't sound wildly out of line with what we might expect I think in the near term there are some kinds of CO2 removal technologies that are ready to deploy and avoided deforestation is a good example but there are also some limits to how far those can go especially on the natural climate solution side and we need to be attentive to the to the full set of social and political and economic issues that are likely to come up in the future as well as the pure technology ones so the the mix is important we need to make sure that we don't put too much emphasis on any particular technology and we especially need to avoid this mentality where we where we essentially kick the can down the road by assuming inappropriately we will be able to deploy vast amounts of of carbon removal technology in the future back to your revenue oh thanks thanks CJ for a wonderful discussion now we're in this in the Q&A from the audience and I must say that this has been the most active audience with a lot of questions I'm not sure we can get through all of them but we're trying to group them and working hard behind the scenes trying to identify the ones that could that could highlight some of the issues that we discussed earlier so the and so we'll try to go through as many as possible so short answers would be terrific so Ajay the first question is for you what role does sequestering CO2 from hydrogen production in a plane to Shell's business plan or is Shell trying to produce only renewable energy or fuels without natural gas and oil no no thanks thanks for that question no very much so blue hydrogen and green hydrogen are going to be very much part and parcel you know of the package I believe that blue hydrogen is going to be around for a while to come electrolyzers based hydrogen green 2d green hydrogen products are beginning to get a lot more into the mix of things there are some major projects that we've announced recently in Europe with an ambition to get to kind of you know from 200 megawatt scale kind of electrolyzers to a gigawatt scale electrolyzers really beginning to think about generating hydrogen at scale but the dominant source of hydrogen is still currently coming in from steam based reforming smr based technologies how do you combine that smr with ccs so you can truly get to you know a point where you you have an alternative to generate hydrogen at scale so that it truly becomes and fulfills its promise that's been around for many decades to become part of you know a genuine energy vector so we are looking at it not just at the green hydrogen production that's a significant part of the business but blue hydrogen is very much part and parcel of the mix second question carbon emissions from food waste and if I don't know if who wants to so there's a significant carbon emissions what can we do to reduce that and would that would that make a difference I can give the quick stats around the world about 40 percent of the food that's harvested doesn't get eaten in poor countries most of the losses are between the farm and the distributor in the rich world most of it's between the distributor and the and the and the customer and things that's just not eaten so if if there were a way to address that 40 percent of food that's wasted we could potentially decrease the land required for agriculture by 40 percent and deploy an ambitious set of natural climate solutions or forest restoration that there there's there is definitely a there there but decreasing waste is a is a hard challenge it's in the poor world it's things like spoilage and insect attack and in the rich world it's it's finding a way to match the portion sizes in restaurants to what people really want to eat and I think it's it is an important area for a dedicated focus realistically I think we're only going to make gradual progress on it if we could have food waste in the next three decades by the by the middle of the century that would be an amazing accomplishment and it would really contribute to our portfolio approach to solving the climate challenge right we talked a lot about agriculture or just photosynthetic mechanisms of plant trees etc as a forest station and so that while that is true we're also finding the climate to change and so there are heat waves there are droughts there are in the fires so is there something we need to think about in terms of looking at you know forestation or agricultural practices to develop those resilient photosynthetic organisms that can sustain during the climate change you know that a real challenge with all these natural climate solutions is that the carbon needs to stay in the ecosystem in the forest or the soil or the grassland essentially forever for the solution to make sense and as we've seen in California and around the world increases in disturbance are making that increasingly difficult so if we do want to see durable solutions on the natural climate solution side the most important thing is to limit the amount of climate change that occurs most of the ecosystem processes will continue to operate in the historical ways if we limit warming to 1.5 or 2c above pre-industrial if we got much warmer than that we will almost certainly see an increase in the kinds of disturbance events like the massive California wildfires that are releasing large amounts of carbon to the atmosphere are there prospects for engineering ecosystems to be more resistant to these to these carbon releases it I guess it's possible but I don't think that's where we should be making our investments I think we should be making investments in limiting the amount of climate change so that the traditional historical ecosystem processes can continue to operate right next question this was Sally if you reduce our atmospheric carbon dioxide from 400 ppm to 300 ppm let's say we were able to do that is there enough underground carbon storage capacity yeah the the underground storage capacity for CO2 is immense there have been a number of global studies and indicating that you know up to 10,000 gigatons you know maybe possible and it can even certainly be more because those assessments didn't include for example offshore formations if we look sort of practically what we may expect between the now now in the end of the century 2,000 gigatons of CO2 would be an enormous amount of sequestration and there appeared to be no fundamental limitations to to doing that now that's not to say it's available everywhere you know that just like all natural resources that they tend to be have higher accumulations in some areas and lower in other areas so if we want to do this at scale we can't expect that every country is going to be able to do this some places like Japan for example are primarily volcanic rocks and and are not terribly suitable but there's some parts of the world like the Middle East and North America with with vast resources the other thing that I haven't mentioned is there are studies now trying to look at putting carbon dioxide into volcanic rocks in particular they're doing this in Iceland and the idea there is instead of storing carbon dioxide as a supercritical fluid under high pressure and so forth that you could actually react the carbon dioxide with the rocks in situ meaning underground and convert the CO2 to minerals if it turns out that can be done reliably and at the significant rate that would vastly increase the total capacity even beyond the enormous potential we have today but probably more importantly it would make it that you could do this in more parts of the world and India is a very good example it's underlined by a massive amount of volcanic rocks and right now they don't have great alternatives in more traditional options for sequestration so if we can show this would work that would be very beneficial for places underlined by volcanic rocks actually let me just follow up with Ajay on this given the magnitude of carbon management do you think oil and gas industry will become a carbon management industry in the future and if so do you have the capacity to to put carbon storage underground yeah so suddenly I think the oil and gas industry has the breadth of knowledge and capacity to be able to do this at scale I don't think there are many industries that can actually do this and as Sally rightly pointed out we don't think that the pore space is the limitation you know there is a plenty of depleted oil and gas reservoirs also anywhere from 700 to a thousand gigatons of capacity that is available there also the oil and gas industry knows how to do things at scale again we come coming back to kind of where we started we know how to deal with co2 co2 pipelines have been around for a long time there's thousands of kilometers of our pipelines dedicated for co2 service that have been around we know how to inject this we know how to ship it we know how to transport it so yes I do believe that the oil and gas industry is actually pretty well positioned to play a pretty central role to kind of you know just tackle this and yeah whether it's going to become solely a co2 business or not I don't think so I think it'll be a piece of the overall puzzle but I do see a significant role for us in there right the next question is for Chris given that oceanic carbon fluxes are not included or claimed in IPCC GHG reports due to high uncertainty do you see that as a problem how might CDR efforts be evaluated in terms of net removals instead of gross removals Chris the oceans take up a lot of co2 now there is no question and you know sadly already addressed the the question of whether we might use ocean fertilization to increase net fluxes yeah one of the things that I think it's super important to keep in mind is that we currently receive essentially a giant free subsidy from the oceans and from ecosystems on land taking up about 55 percent of annual co2 emissions and simply preserving those is is going to take some real efforts there are opportunities for increasing co2 uptake in the oceans but they they tend to be technologically challenging they're they're hard to quantify it's especially difficult to figure out how you would allocate credit for accomplishing each of these and so I'm a big habit of continuing to research how we might increase oceans co2 uptake but I think the idea that the oceans present an opportunity for dramatically changing the overall kind of balance that we've talked about it is relatively small and that the bulk of the effort should be put on the the core set of co2 removal technologies we've been talking about uh flue gas carbon capture and storage direct air capture if we can get the energetics to work out and then natural climate solutions especially the cessation of cutting down tropical forests yes so this one is actually more about the distributional impacts of these technologies we have a wide a range of technologies that we discussed so far could you briefly touch on um and this is open to anyone the potential equity and distributional impacts of any of these technologies that we should possibly be wary about let me start with one thought part of the challenge we face in rapidly decarbonizing is the fact that in poor parts of the world the economic development trajectory is at a point where a full embrace of of non-emitting technologies isn't consistent with the other parts of their infrastructure and society so one of the real motivations for thinking hard about carbon removal technology is to allow appropriate utilization of fossil fuels for the coming decades in poor parts of the world that that don't yet have the the other pieces in place in order to embrace renewable non-emitting technologies and a second factor that's an important equity dimension of all of this is that the difficult to decarbonize parts of the economic system long-distance transport manufacturer of cement and steel are are products that are especially important as countries transition from um non-industrialized to industrialized and so there are real equity implications associated with these difficult to decarbonize parts of the economy i i think that CO2 removal can be an important component of an equity focused climate solutions portfolio great thank you i'll just offer another thought um you know i think that one of the risks we face now is that you know adding carbon management to our energy supply you know will not be free and and and in many parts of the world we can afford to pay more but there are many parts of the world who are still struggling to for the first time get access to energy and there really isn't a substitute for fossil fuels in terms of reliable transportation fuels or or even providing you know 24-7 reliable electricity so i think that in those places that you know the basic energy access is still lacking to support you know comfort health and and and industrialization that that you know that they need the opportunity to build out their energy systems before the same norms are applied to them regarding uh the kind of carbon management we may expect in uh places that are more able to afford uh you know moving towards carbon neutrality sooner rather than later yeah and just just very quickly if i could just add one more thing to that uh totally thanks for bringing up the energy access part because that's kind of a very huge part of kind of how we think about this issue also in terms of equity and access but one other thing that i would add from a technology perspective is as we think about also natural climate solutions i really think it's important to pay attention to what's happening in local markets versus applying a model that works perhaps in the west to everywhere else in the world there is a tremendous amount of local intelligence these are some societies that have been based upon agricultural economies far longer than we have you know they have been forests which have been protected for you know centuries and there is a tremendous amount of technology and know-how and local intelligence that's also going to have to be tapped into as we think about this you know tackling this problem holistically back to you ej thank you aje back to you arun okay thank you and i wish i could ask all the question there are so many this conversation could go on for a long time but let me give this opportunity back to the panelists and maybe you could take a minute each to offer your holistic view of the topic of atmospheric carbon removal and what are your key takeaways let's start in reverse order aje you go first great thanks arun that's been a really great discussion i think at a headline level for me what i would say is that i actually am very optimistic that this is something that we are going to be able to tackle together you know as a society and as a public private academic you know community together i however do think that we've got to be careful in not thinking about any of these technologies as a silver bullet because they don't exist the second part is that we have to continuously be thinking about things in parallel and not in sequence so when we think about negative emission technologies this is something that we have to start thinking about here and now but not as a substitute for the need for deeper decarbonization so i think when we put all those things together i really feel that there's plenty of grounds to be optimistic about the future thanks arun chris well i agree with aje that natural climate solutions carbon removal technologies can be an important part of an overall portfolio but they're only a part of the portfolio and they they probably won't be the dominant component i think the other element that has been a little bit missing from today's conversation is the sense of of urgency and if we are to maintain and limit warming to the range where the impacts are are acceptable where we can deal with them with adaptation we really need to be going many times as fast as we're going now and the sense of finding the accelerator pedal on our portfolio of actions is super important and we can't let distant prospects for CO2 removal take away the focus on the urgency for action now thank you sally yeah um i agree with everything that's just been said i'll just add two more thoughts um by nature uh natural climate solutions and and even engineered solutions for carbon removal you know involve massive amounts of land uh that and once we have anything that involves massive amounts of man there'll be impacts to ecosystems there'll be impacts to people there'll be impacts to the economy so i think as we move forward and think about this new set of solutions we really need to figure out what are those win win win solutions you know winning for the people winning for the economy and and winning for the environment and i i think a world where we study each of the technology and isolation from how it's going to impact the societies and and how it will you know affect people's jobs i don't think we can do that anymore you know going back to adi's point we can't do this in sequence we need to do these in parallel so we need much more engagement than the social sciences in this research um and then finally you know many of these ideas for carbon dioxide removal are really nascent and we really need r&d um you know high quality r&d that looks not only at how you do them but how effective they are how we're going to monitor them how you're going to monetize them and and i think it's time to to to increase the level of investment in the set of technologies ladies and gentlemen this has been a terrific discussion sally chris and adieu thank you so much for offering your thoughts and perspectives and educating us on this important complex issue thank you eija for representing the student community and thank you to all all of you joining us around the world we hope you found today's global energy dialogue informative relevant during these unprecedented times please join us two weeks from now for a conversation with two investors eric toon from break to energy ventures an avic day of the canada pension plan investment board again please register on our website gef.standford.edu and note the time and date wednesday october 14th 9 15 to 10 45 a.m california time we will now conclude our broadcast for today's program on behalf of the entire stanford pre-code institute for energy we thank you for joining us and we will see you next time