Science Friday - Degrees of Change: Building Materials. Feb 28, 2020, Part 1

Episode Date: February 28, 2020

In order to slow a warming planet on track to increase by 2 degrees celsius, nearly every industry will be forced to adapt: airlines, fashion, and even the unglamorous and often overlooked building materials sector.  Just like the farm to table movement, consumers are increasingly thinking about where the raw materials for their homes and cities come from, and how they impact climate change. And in response to this concern, the materials sector is serving up an unusual menu option: wood. “Mass timber” is the buzzword these days in the world of sustainable building materials. Architects are crazy for it, engineers praise its excellent structural properties, and even forestry managers are in support of its use.  Of course cutting down trees to curb carbon emissions seems counterintuitive at first. And there are skeptics who doubt whether wood is strong enough to build future city skyscrapers.  Frank Lowenstein, Chief Conservation Officer with the New England Forestry Foundation and Casey Malmquist, Founder and CEO of timber company SmartLam North America, join Ira to explain why the hype over mass timber’s potential to mitigate climate change is the real deal.  And as the popularity of sustainable mass timber rises, big carbon-emitting industries like steel and concrete are facing pressure to address their role in the climate crisis. One steel company out of Sweden is aiming to make it’s product carbon-neutral by 2026 by replacing coal with hydrogen in the steel-making process. And other researchers are hoping to make concrete more sustainable by using ingredients that would actually trap carbon inside the material.  We hear from Martin Pei, Chief Technology Officer of European steel company SSAB, and Jeremy Gregory, Director of the Concrete Sustainability Hub at MIT, about how the traditional building materials sector is going green.  Plus, architect and structural engineer Kate Simonen of the University of Washington talks about the need for more sustainable building materials to construct homes for an estimated 2.3 billion more people by the year 2050. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Because we are in a climate crisis, we open the next chapter of our series, Degrees of Change. Our series explores the challenges of a changing climate and how we as a planet and a people are adapting to the crisis. This hour will be talking about the connection between building materials and the climate. Can the construction industry become carbon neutral? Why not get involved in our coverage? Please, sign up for our climate newsletter at at Science Friday.com slash degrees of change. But first, we're going to check in with the gatekeepers, the decision makers, the controllers

of the purse strings. Earlier this month, someone with some pretty big purse strings, Jeff Bezos of Amazon fame, pledged in an Instagram post to spend $10 billion of his money on climate issues, starting something called the Bezos Earth Fund. Joining me now to talk about that. Another recent climate news is climate journalist Emily Atkin, founder of the Heardons, The heated newsletter. Welcome back Science Friday. Hi. Thanks for having me. Tell me about this new contribution idea. Oh, yeah, Jeff Bezos. What did he, what did he do? And why did he put, what, $10 billion into this fund?

$10 billion. It's a lot of money. So he announced last week, actually, that he was creating the Jeff Bezos, you know, Earth Fund. And over the next 25 years, he said he'd contribute $10 billion of his own money to invest in an adaptation. mitigation, climate solutions. It's a very big philanthropic effort, and it's going to, it is very generous, but it's going to do a lot for Jeff Bezos personally as well as hopefully for the planet. Are there any particulars, any details of where and how that money would be spent?

Oh, no. No, he's like, I'll tell you later. Basically, it was just an Instagram post of a picture of the world and him just being like, I'm going to give some money to the world. And actually, that's the most interesting part about it because, you know, with $10 billion, Jeff Bezos is basically going to buy a lot of solutions to the climate crisis. He's basically going to set the agenda for a lot of how we approach this problem that affects everybody. So he doesn't say what he's going to do. I mean, he could make a choice that a lot of people, you know, climate change isn't a simple. thing about is it real, is it not? There's a ton of ways that we can approach solving the

problem. And by putting $10 billion into it, Jeff Bases is exercising quite a bit of control over that situation. So we'll have to just wait and see how that shakes out. Let's move on. We're almost at Super Tuesday. The primaries are heating up. And there is still no real climate questions at the debate. They don't ask those questions as much, do they? No, this is the second debate out of 10 where there was no climate questions asked, the one the one in South Carolina this week. And that's sort of, you know, that's disappointing just given the urgency, severity, complexity of the problem of climate change and also just the general public interest. You know, Democratic voters consistently rate climate change as their number two issue except for

health care. And it's even rising in the priority for just regular voters. this. George Mason, Yale poll just came out that said when choosing a candidate for all voters, climate change is the fifth most important priority. And when choosing a candidate for liberal Democrats, it's the first most important priority. So we should be seeing these questions, I think, as a journalist, but we're just not right now. Considering that all the Democratic candidates are in favor of some kind of a greening, what pointed question should they be asked? What would you like to hear that? What questions would you like to hear them answer? Oh, there are just so many questions we could hear. I would love to hear them answer. I mean, Bernie Sanders is the frontrunner right now, actually. And one question that I would love his campaign to be forced to talk a little bit more on is their position on a carbon tax, which a lot of economists say would be one of the most effective ways to combat climate change. But there's also a lot of people, especially in the environmental justice community, that say that solution is unacceptable. And Bernie Sanders hasn't given a really clear answer on where he stands on the idea of one.

So there's that. I mean, I would love to hear what they, what the candidates think about, even just billionaire philanthropy when it comes to climate change. Should these, should solutions be more democratic? I think that would give us, or should they be, should we be depending on very rich people out of the quote unquote goodness of their hearts? I think that would, I think that would give so much more insight on how they would solve the problem. I actually did an open thread discussion on my newsletter where I just said, what would you ask? And, you know, we got 70 different people with different questions. I mean, there's no

shortage of material. Yeah, so just saying, you know, I would support some kind of Green New Deal is not telling us very much. That doesn't really mean anything. Yeah. Speaking about the climate, there is a new study out this week about the media and climate coverage in 2019. Tell us a bit about that, please. Oh, boy. More bad news, huh?

Well, it just depends on how you look at it. You know, climate coverage on broadcast news networks increased actually 68% over last year. Unfortunately, it's still made up less than 1% of coverage on the major news networks. So that's less than four hours total of climate coverage over the span of a year. So again, the coverage of the climate crisis in our general journalism, outlets is just not reflecting the urgency or the severity, complexity, or public interest of the problem. We still have such a long way to go. Why are they so unconnected?

If all the surveys are showing how interested people are in climate change, why are they showing so little regard for that opinion? Personally, I think it's because especially in mainstream traditional news outlets, you know, I've worked in these outlets. there's a, you don't want to, if you have to really cover climate change in a compelling way, you have to really admit that there's a problem that's very urgent to solve and you have to have this sort of, you have to come from a place that's not really grounded and level and, you know, quote unquote balanced. So I think it's really hard for some of these entrenched news editors to admit that they have to come at this problem at a place where they have to just reject one side of our debate in America, that climate change isn't real and doesn't deserve being solved.

But once you do sort of admit the truth of the problem that like that there's so much, that this is a problem we should solve, there's so many interesting stories to tell. So I think there's just a block. But I also think that I do think we're moving past it and I see it every day. Yeah. Yeah. It's also the question of having to spend money to hire more people to cover it. But we won't go that way because that's what I remember when I worked in that business.

Let's go on to there's news this week about I thought something really interesting. A big oil sands project in Canada that might not be going ahead now. Yeah, there's a big oil project called the Frontier Development in Canada that just got out of nowhere. The company just said we're not even going to be pursuing this project anymore. And it's kind of crazy because, you know, this had been a fight in Canada. among climate activists and oil people, pro-o-o-oil people for like years and years. And ultimately, it seemed to really come down, and it's a big political debate, but ultimately it just seemed to come down to the economics of the situation where just oil prices are low.

They're going to remain low. Oil is sort of increasingly seen as a bad investment. Fossil fuels in general are kind of seen as a bad investment, especially really dirty ones like oil sands, which I know a lot of people in America don't know about, it's arguably even dirtier than coal, this type of fossil fuel production. And that's actually how things get changed, don't they, when big business decides that it's just not profitable to do something. You can say you can use all the ethical or moralistic, you know, it's the planet, it's our kids, but it comes down to just the money. And that's when the spigot, so to speak, gets turned off.

Right. And you are seeing that increasingly, you know, there was a big story a couple weeks ago on CNBC, this, this, very, you know, this investor guy was just like, I'm done with fossil fuels. Like, I'm, I'm not here to make friends. I'm here to tell you how to make money. And I can't tell you to invest in oil and gas stocks anymore because we got new managers in town, you know, and there's been so much news about financial managers, asset managers, just saying they're moving away from fossil fuels. And that's partially because of activist pressure. Finally, we, this is an interesting story also. We all know about the Greta, but there are some conservative groups are trying to create, and promote a sort of anti-Greta teenager?

Yeah, they sort of took, sorry, it's just so ridiculous. They took, you know, the, what's been working for the climate movement, which has been, you know, this figurehead, this person who's really inspiring, and they're sort of paying to create their own version of it, but of like a far-right young, sort of childish-looking woman who says climate change is not real, and oil is great. It's very weird. And she's going to be speaking at a very conservative conference coming up. At CPAC, yeah. So that'll be interesting. Her mother is a lawyer for the German far right group.

Very controversial German far right group right now. She's being paid by the Heartland Institute, which is a climate denial think tank funded by the Mercer's, billionaires. And it's an interesting way for them to sort of admit that, you know, that they really need a counter strategy. The youth are very important for the climate denial movement to influence. And so this appears to be their attempt. It reminds me when the conservatives used to say, why don't we have a conservative Saturday night live thing? Because if they can do it, we could do it. Yeah, I guess they would have to pay people a lot more to be on that show.

because, you know, Greta's not being paid to do what she does. Interesting. Thank you, thank you, Emily, for taking time to be with us today. Have anything really cool coming up your covering? Yeah, actually, next week my newsletter is doing a full week devoted to how the fossil fuel industry is influencing different public school curriculum around the country. So I'm excited for excited. I don't know if that's – I'm interested to see how that goes. Yeah, it's a good story.

You come back on and talk about it, okay? I would love to. Emily Atkin, climate journalist and founder and author of The Heated Newsletter. Thanks for taking time again to talk for us. You're welcome. When we come back, excuse me, how major construction industries like wood, steel, and concrete are rethinking their role in this era of climate change. Different kind of wood construction. You know, skyscrapers made a wall out of wood and also new kinds of concrete and steel.

You know, a lot of CO2 is used in this industry. they're talking about how they can cut back on that and maybe even lock up CO2 in the wood in the buildings. Interesting stuff. Stay with us. We'll be right back after this break. This is Science Friday. I'm Ira Flato. Continuing with our degrees of change ideas in order to slow climate change in a world on target to warm by 2 degrees Celsius, nearly every industry will be forced to adapt. The airline industry, the fashion industry, even the unglamorous and often overlooked building materials sector, one of my favorite industries. And it's just like the

farm table movement, consumers are increasingly thinking about where the raw materials where their homes and their cities come from and how they impact climate change. And in response to this concern, the material sector is serving up an unusual menu option. Timber. We're not talking about your two-by-fours here. We're talking about boards and panels of wood that are glued together to make ultra-strong building blocks and beams, out of which you can make an entire building without steel. Mass timber, it's called. It's a buzzword these days in the world as sustainable building materials.

Architects are crazy for it. Engineers praise its excellent structural properties, and even forestry managers are in support of its use. So we asked you, would you consider living in a timber city if it meant reducing your carbon footprint? And you've answered. Here's David from North Carolina. He had this to share. I thought about this question and decided that I would.

But I also thought about living in a city that's mostly made of stone and cinder blocks, bricks. Then I remembered that the process of creating cinder blocks has a massive carbon footprint, as does cement. But we also heard from people like Pallucid in South Jersey. Who thought of this question? We need to grow more forests, not chop them down for cities. Not only that, I'm sure that there are better materials and stronger for building cities in the face of the turbulence of global warming. It is strange when you think about it. Why would cutting down trees to build homes be a greener way of building?

And Ken would really be sturdy enough to hold up something like a city skyscraper? Here to help answer these questions and explain why mass timber is geared. up to be the building material of choice to fight climate change are my guests. Let me introduce them to you. Kate Simonin is Director of the Carbon Leadership Forum, an associate professor of architecture at the University of Washington. Welcome to Science Friday. Glad to be here.

Frank Lowenstein, Chief Conservation Officer with the New England Forestry Foundation. Welcome to Science Friday. Thank you so much. Casey Malmquist, founder and CEO of Smart Lamb, North America, a cross-laminated timber company. Welcome to Science Friday. Greetings from beautiful northwest Montana. Nice to have you. And we also want to hear from you, our listeners out there. Have you worked

with mass timber or cross-laminated wood or use them in your home? Our number 844-8255 is our number. You can also tweet us at the SciFRI and let us know what you think. Frank, let me begin with you. Let's address the elephant in the room. Cutting down trees will help fight climate change? How do you explain that? Well, it's important to recognize that just like all of us, trees have a have a life cycle and they have a maturity. And so we

really need to keep our forests. You know, we have the forests of the world store as much carbon as all of as is in the atmosphere already. So if we lost all the forests, we would have a big problem. But the individual trees within the forest are eventually going to die. and when they die, some of the carbon is incorporated into the soil and some's released back into the atmosphere. So wood buildings are potentially a way to harvest the trees when they're mature and lock that carbon up for hundreds of years more. Kate's a minute. Is mass timber movement exciting to you as an architect? Yes. All buildings are exciting to me as an architect. And using materials in new ways and in experience them is part of the creative process of designing and building. So yes.

And well, so what in particular is exciting to you about this kind of timber? Well, there's two things that are exciting. One thing that is exciting is that it is new methods of expressing building materials. So tall, tall wood buildings give a different expression of building. The other thing that's exciting is that wood does demonstrate the potential for biological materials to take carbon out of the atmosphere and store them in long-life building products. Casey, you started the first cross-laminated timber company in North America. For those of us who can't see what a piece of timber is like, and can you explain how you make the material, what it looks like?

Yes, fundamentally, it's fairly simple. We take primarily 2x6 and 2x8 boards that we buy direct from mills. We lay them up basically in layers that, run perpendicular to each other. We can go up to nine layers thick, which is approximately a foot thick. Our operation, we can do a panel up to 11 feet wide and 52 feet long. All of that, those layers are connected with a very high-tech, but very safe, innocuous adhesive. It's all bound together under a hydraulic pressure to form a solid plate of structural timber. When all of those individual boards are combined, we end up with a structural element

that is equal in strength to concrete and steel for a similar profile. You know, I'm thinking when I look at it and when you talk about it, I'm thinking of a massive piece of plywood. Would I be far off on that? No, there's been the term plywood on steroids. troids tossed around. It is similar in design, you know, as an engineered wood product, and it's kind of relying on the same principles. Is the lamination actually make it stronger than building with steel?

Yeah, pound for pound, the wood fiber is stronger than steel, and it has a lot of sort of unique characteristics. One of them that I really like is what's called ductility, is particularly when compared to concrete, is concrete is very brittle, and when put under pressure and when it fails, it ruptures catastrophically, where wood has this ductility,

sort of flexibility and strength. You know, imagine watching a tree in a windstorm, that tree is arching across the sky several feet. That strength is not because of its rigidity, but in fact because of its ductility. And that sort of material property translates into some of the benefits you get out of constructing with it. You know, when people here have a wood constructed building,

the first thing that comes to mind is fire, right? How fireproof or how fire resistant would this construction be? Well, that's an interesting question. I'm very counterintuitive, and we've done extensive testing to prove this out. But when you mask timber together, it starts to behave very differently. And think about it if you're an outdoors person. When you try to create a fire, you typically have to carve the wood up into very small pieces, create surface area, and that will combust rather easily.

But when you mass it together, it's trying to lighting a log with a big lighter. You won't be able to get that combust. There's a very simple process called a charing process where that combustion takes place on the very surface of the wood. It gets in, you know, an eighth of an inch and loses its combustion source in self-extextime. distinguishes. Ironically, wood actually behaves better in catastrophic fire conditions than concrete or steel do, and that would actually get stronger in temperature where concrete and steel actually get weaker. Frank Lowenstein and remind me of a big redwood forest trying to light a redwood with a match,

right? Yeah. Yeah. I've certainly been on many a camping trip where I've put too big of a log on the fire and waited for it to catch from the little things I had burning and nothing. happened. Are forestry managers in favor of this kind of material building? Forestry managers, particularly ones who are in it primarily for as a product, as opposed to a lot of the small private landowners who may own forests for heritage reasons or because they love trees. But the guys who are in it and the gals who are in it for a product, they're for any use that's going to give them a new market. Let's go to the phones. 844-7-24-8-255.

Dave from Delevin, Wisconsin. Hi, Dave. Hi, I appreciate your time. I love wood. I love the concept. I think you briefly touched on one of my concerns, and that would be the toxicity of adhesives used and any other chemicals for, well,

I was going to say, fire retardant or other products, but I appreciated the comments you just made about how it behaves under those conditions. Has this stuff been tested for off-gassing over the long haul? Let me ask my guess. Casey? Yes. So our adhesive is a single-part polyurethane resin.

It is non-VOC, no volatile organic chemicals, does not off-gass, has no formaldehyde. It's basically, I mean, it's kitchen grade. You could eat it, not recommended, but it, yes, has. very, very innocuous properties. And Casey, haven't all the manufacturers now, aren't they using a similar adhesive? The majority of them are using them, yes, and a lot of that is guided by fire code. There are additives in that to promote fire resistance. And, yeah, so virtually all their producers are using that.

We have a few tweets and a call coming in, O'Keemo tweets. I've worked with laminated wood structures in the south, and it's a solid building material for most structures, i.e. towers less than 12 stories or so, as long as they use sprinklers. Jackie tweets, I've been using paralam, a form of mass timber in my sculpture. It has a very beautiful and unique texture. It's easy to work with, and it's cheap. How tall can you make the structures, Casey?

Well, that's up to the architects and the engineers. The tallest building that I'm aware of right now in place is an 18-story building. There are designs out there for buildings exceeding 30-stories, which I think will come online here fairly soon. That's all an engineering issue, but that can be resolved, again, with inherent strength, and in combination with other materials, including concrete and steel. Kate, you're an engineer, a building engineer. How tall do you think you can get these? Well, there's always the question of how tall you can get something.

I think there's a little bit that it's important to recognize how tall should you or what's the best use of material for the right spot. So an ultra-high high-rise with wood columns would start to become ridiculous in terms of the size of the columns themselves. And then there's the issues of, lateral stability, how does it hold up for wind and earthquakes? So I think, you know, what architects and engineers are excited about is having another material in their toolkit and being able to choose the materials that are right for the project. So I guess I'd advocate for, there's a lot

of potential for taller buildings out of wood, but we shouldn't just be narrowly focused on that it has to be all wood. Diversity is good. Yes. Let's go to the phones, Albert in Miami. Hi, Albert. I hear the waves. Hi there. Yes. Yes, I just wanted to bring me to your attention. I'm with third wave volunteers. We were responding to Hurricane Dorian in the Bahamas and the Abaco Correst there was pretty severely damaged and we noticed it. We started to ask some questions and partnered with University of Miami, Perkinson, Will, architectural firm. We're kicking off a large-scale mass wood project utilizing the felt abaco pine that's in the Bahamas based on the old Bahamian clapboard house builds, which were built by the original boat builders in the Bahamas.

It's been a useful project, and in the Bahamas, they seem to have weathered the storm better than many concrete homes. Thanks for that call. That's a really interesting point. As climate change progresses, it's not only something we want to prevent, but it's actually a threat to forest. You're seeing rising mortality, things like the fires in Australia, but also beetle kills, the hurricane that was mentioned in the Bahamas. And so we're going to have trees that have been damaged or killed, and what are we going to, what use are we going to make of those? If we can turn them into mass timber, use them instead of concrete and steel, which both require right now massive amounts of fossil fuels to produce, that's a good thing for the climate. It's a good use for the material.

I'm Ira Flater. This is Science Friday from WNYC Studios. And that's an interesting point that you make because you can use, you know, wood that normally would not be available in construction, right? Casey, you could make small, use smaller, less desirable pieces of wood. Well, there's a little bit of a myth with that. So small diameter in our world is probably 12 inch diameter and greater because we do have to get, to the dimensions of 2x6 and 2 by 8. And also the inherent strength of that wood is important. That translates directly to the strength of the finished product. So we are somewhat selective in getting, we can't use garbage wood to make a high-quality product. But we do, this does not require old growth material, does not, you know, require massive trees.

What we're trying to focus, all of our product is produced from sustainable forestry practices. So all of this is, you know, basically it is that farm-to-table concept is we only are able, you know, we're only going to consume what we're able to produce. One last tweet came in from Julie who says, Can reclaimed barnswood and timbers be used for larger building projects? Can you make those into this kind of wood, Casey? Typically not, no. You know, Barnwood would not have all of our product has to be graded and rated for structural properties.

So some of that reclaim probably would not, unless we use it for a face material for aesthetic purposes. But structurally, again, it has to be a graded structural material. Frank, you're happy with the way this direction is going and using the forest? way? You know, I am. I think this is a key part of the solution to climate change, and we have such a crisis in front of us. You know, more than 10% of the world's emissions of CO2 come from producing steel and concrete. So we're going to need to cut that, just like we need to cut the emissions of every other sector of society. This is a great way to do that if we can use wood instead of steel and concrete. Well, the folks in the steel and concrete industry,

are also coming up with trying to be more sustainable. And we're going to talk about that right after their break because they have some interesting ideas that we'll get into. But I want to thank my guests who we've had on my guest this hour. Kate Semenon, Director of Carbon Leadership, Foreign, and Associate Professor of Architecture, University of Washington, Frank Lowenstein, Chief Conservation Officer with the New England Forestry Foundation,

Casey Momquist founder and CEO of Smart Lamb, North America, a cross-laminated timber company. Thank you all. Very taking time to be with us today. As I say, when we come back, we're going to talk about the concrete and steel industries in the face of competition from timber, how they are responding to the pressure of climate change and to evolve to becoming more green. They've got some interesting answers. If you'd like to talk about it, our number, 844-724-8255. You can also tweet us at Cy Fry. Maybe you're in an industry. We'd like to hear from you. Stay with us. We'll be right back after the break. Friday comes from Bloomberg Philanthropies Beyond Carbon, moving the United States toward a 100% clean energy economy. Learn more at BeyondCarbon.org. This is Science Friday. I'm Iraflato. Our degrees of change series continues, and we're talking this hour about how the building materials industry is

responding to climate change by reducing its carbon footprint. Big industries like concrete and steel are finally responding to the threat of climate change by making these materials carbon neutral or at least curbing emissions sustainably and substantially. Steel is one of the biggest carbon emitters in the world, not only because it's energy intensive, but because it relies on burning coal as part of the chemical manufacturing process. So is there an alternative? It's a tough problem to solve. But at least one steel company is looking to overturn hundreds of years of tradition by using

something else, hydrogen. Earlier this week, we spoke with Martin Pei, chief technology officer for SSAB, one of the largest steel companies in Europe. He told us for hundreds of years the process for making iron used in steel has been the same. Iron oxide and iron ore is combined with coal in a chemical reaction that creates iron

and emits CO2 as a byproduct. Hydrogen can do in principle of the same job chemically. hydrogen then can combine with oxygen from iron oxide. And then from that process, we get iron in a solid form instead of liquid form. And then the byproduct will be water. But one of the big hurdles in scaling up this process is getting enough hydrogen. Coal we know is abundant. Hydrogen has to be made.

Hydrogen can be produced by using green electricity. CIT can separate the hydrogen from oxygen atoms containing water. And then we can use hydrogen to make solid iron from iron ore. Then the solid iron is melted together with recycled scrap. Then we can make the high-quality steel products that we are making today. Martin Pei is chairman also of the board for a new company that was created to work on this technology called hybrid. and they're aiming to have carbon-neutral steel ready for market by 2026. Still with us to talk about building materials and building is Kate Simon-N-N,

director of the Carbon Leadership Forum and Associate Professor of Architecture at the University of Washington. What do you think, Jake, how is the steel industry doing with this carbon-neutral idea? Oh, it's tremendously exciting that we'll see across the building sector from steel to cement, to even carpet, manufacturers are really innovating not just about being more efficient, but also transforming how they, how the chemistry of how they make products with the goal of reducing carbon emissions and ideally figuring out a way that carbon is sucked from the air and turned into long life building materials. Of course, that problem that he talked about is, well, can we get enough hydrogen? Can we make hydrogen sustainably and green? so we don't take more energy to make that energy? Well, that's a tricky question.

I'm not a chemist. But, you know, what I do see is that there is growing collective momentum about both the urgency of this issue and the potential for really positive solutions. So not one industry or one individual can have all the solutions, but if we work together, you know, the hydrogen fuel production and the steel production and how we design and build, build, The building sector might be surprising to know is responsible for over 40% of global greenhouse gas emissions.

And if we look at new buildings built today, as much or more than half of their impacts will be from the material production. And we need to build more to have a healthy, happy world for everybody. So we can't just stop building. We need to figure out how to build and have the building be part of a climate solution. Yeah. And of course you're not talking about, as you said in the last segment, there is room for every kind of building material. You're not talking about, or no one I think is talking about totally doing away with concrete or steel, but reducing it. Using all of the assets that we have very efficiently

at their highest best use. So yes, everything. All right. Let's move on to concrete. One of my favorite topics, concrete offers another challenge to fighting climate change. The production of cement and then concrete releases a large amount of carbon dioxide. And one person who knows a lot about how the concrete industry is tackling this issue is Jeremy Gregory, a civil and environmental engineering researcher, executive director of the Concrete Sustainability Hub at MIT. Welcome to Science Friday. Thank you. I'm delighted to be here. For people who don't know how carbon-intensive concrete making is, the process, give us a little thumbnail sketch. Well, as many people know, concrete is made up of cement, which is like a powder that you mix with water and then sand and gravel. So

concrete is the mixture of those four ingredients. Now making cement relies on digging up limestone from the earth, heating it up to very high temperatures, and then turning it into this powder that we call cement. So actually on a per unit weight basis, concrete is pretty cheap and has a low and environmental impact. But the issue is that we use more, we use concrete more than any other material in the world except for water. So on a per unit weight basis, it has a low impact, but because we make so much of it is why we should really be focusing on it as an opportunity to lower greenhouse gas emissions. And are there experimental methods or methods that are being used to lower the CO2? There are lots of opportunities available today to lower the CO2.

two of cement and concrete. Some of them are about using what we call supplementary cementitious materials. Their waste materials, such as fly ash from coal-fired power plants and slag from steel production, those can be ground up into powders that can be used as a binder like cement and the concrete. So those are pretty simple things that are available today. But there are also some exciting opportunities about technologies that are being developed and also in the marketplace today that use captured carbon dioxide from industrial sources,

such as cement plants or power plants, and using them in the production of concrete or aggregates. And what's exciting about that is with some other opportunities, we can then create concrete that has a net zero or even negative carbon footprint. And so capturing that carbon dioxide from one source, putting it into concrete, and then it's permanently sequestered then in the concrete.

So that's a maybe newer, exciting opportunity. That is interesting. I never heard about that. We hear about CO2 being locked up in wood, but not in concrete. Yeah, yeah. I think it is something that's an opportunity that people don't talk about. And like I said, you know, there's a lot of researchers that are looking at if carbon capture is an important part of our greenhouse gas mitigation strategies, what do we do with that captured carbon? And a lot of people look at sequestration, geological sequestration, you know, deep in the earth. But those are problematic because the carbon dioxide can often leak back out.

Whereas what's interesting about this, using it in concrete is that, you know, like I said, it's permanently sequestered. And studies have been done show that by value and then also just by pure mass, if we can put that captured carbon dioxide in concrete and aggregates, we can make a real significant dent in greenhouse gas emissions. Kate, do you think, you know, the public is looking for things that are green? You know, they're shopping for green clothing. And do you think that if they had a choice between a greener building and one that's just built the way it is now, they would opt to buy or live in something like that? I think it's the responsibility of us as design professionals to show people what is truly possible.

and that's buildings that perform really well and that are part of climate solutions. I think that it's incredibly inspiring to see the youth movement around engaging on this topic. I've worked with middle school and high school students who are looking at creating information about the carbon impact of building materials and spreading the news. I expect that we're going to see a rapid transformation of understanding of the importance of buildings in climate. and a willingness to engage in really testing out new solutions. Let me go to the phones to David in Springfield. Hi, David.

Welcome to Science Friday. Oh, thank you, Ira. And thank you for what you do. The thing I'm not hearing come up here with these guys, and maybe your concrete guests can address this. But like right now in France, they're developing hemp crate, and they've actually finished some buildings made out of our concrete hemp mixture. They're developing hemp wood now to build the fiber products that your other guests are speaking about.

And I just don't think cutting down trees is a way to fix the climate. All right. Let me ask my thanks for that call. What about hemp as a building material, Kate? Well, there's a lot of interesting materials that are really agricultural waste products. So the straw and materials like hemp that are fast growing and reusing, bamboo. So bio-based materials really do need to be looked at from a whole system's perspective and what happens in how they are growing. So forest management and how long their typical rotations are and where are we taking?

You know, the best use would be things that are dead or dying already. But there are, you know, there's a broad range of opportunities here. Jeremy, can I go to my local homes, you know, fix-it store? buy a bag of this new kind of concrete to cement? You can't go to the local fix-it store, but there are a lot of concrete producers that are already using these technologies that incorporate captured carbon dioxide into the concrete.

The other thing, I think that's pretty basic, as Kate knows very well, the architects and engineers just have to start asking for it. And I think it's sort of a really basic thing that when it comes to a lot of construction, we just don't ask for what's the environment mental footprint of your concrete. And I think that's something, it's just a really basic first step we got to do. We got to show there's demand. Can I add into that? Yes, please, Kay.

And that asking is not just the rule of the professionals. That's the asking of the public. So the public can ask these questions and that helps drive change. Owners are more owners, particularly owners who are making large-scale global climate commitments are starting to ask these questions. These questions will need to be asked by everybody. So if I go to my Lowe's or my Home Depot and I say, I would like you to find a way for me to build with the cement made out of the, you know, sustainable cement, they would listen and maybe that would help move the wheel a little bit, okay? Yes.

When I talk to manufacturers, they are discouraged by the lack of people being excited about their innovation. Lows and Home Depot and the people that are selling you, your flooring all need to be asked. They may not have an answer right now, but if enough people ask, they will figure out how to move their market. Our number 8447248255. Let's go to Orlando. Steve, hi there. Go ahead, Steve.

Yes, hi, Ira. Hi there. I'm calling you from Orlando, and I design homes here in Florida and around the country, and I've done some in foreign countries too. One of the problems here in Florida is termites. And it's the number one cause of insurance claims here in Florida. Florida, as well as fires and tornadoes. So insurance is a big issue. People who have their homes designed and built out of concrete block save a substantial amount of money when they

build out of concrete block as opposed to wood. This is not to say that we're not going to have any wood products within the project. We have wood trusses. We have wood furring. We have wood interior walls, wood cabinets. And they're all important and necessary within the architecture of the housing industry. But as far as the main superstructure of the house, we try to use concrete block wherever possible, and that saves a lot of money in insurance. And I just wanted to make a comment about that. Well, don't go away because I have a question.

I want to ask you right after I tell everybody that I'm Ira Flato, and this is Science Friday from WNYC Studios. Our guest, Kate Semenon, has been saying, you know, if we want to change things, we have to ask for them. Would you as a construction engineer or someone who builds homes, would you be willing to ask for concrete block that is made out of more sustainable concrete? Well, absolutely, yes. Sustainability of concrete is getting better and better all the time. And one of the things I've noted from specs that I've seen from ACI, the Concrete Institute, is that adding more fly ash to the concrete.

strengthens it, thereby reducing the need for some of the Portland cement that goes into it. And I'm not an engineer. I'm a designer. Well, one of the things that I've noted is that as concrete products have evolved over the last, say, 15 or 20 years, is that it is more and more environmentally stable and sustainable within the design and construction field. Well, thank you for phoning in and telling us about your work. You're just backing up with Jeremy and Katie, say, Jeremy, a guy in your industry. Well, I mean, there are a lot of people who know about the many benefits of building with concrete.

But I think one of the things that Steve raised that is important is that there are different ways that you can make concrete. People sort of think it's maybe it's just those four things that I mention. But there's really almost infinite combinations of different types of binders and aggregate that you can mix together. they will have some trade-offs in terms of different properties that you're looking for, whether it's strength or stiffness or time it takes to achieve some of those properties. But once again, just comes back to asking people to say, not only am I looking for that kind of performance, but I'm also looking for a low environmental impact as well.

So your green concrete, as I'll call it, is as strong and will last as long as what we have now? You mean these more sustainable concrete? Absolutely. Absolutely. Yeah. If not better. I mean, there's a reason that we still have concrete left around from, you know, thousands of years ago that the Romans were making. Yeah, the best, you know, the longest structures that we have, the equites, whatever. Exactly. Exactly. Yeah. A last word, Kate, on concrete? Well, I think that the caller brought up to a really important point is that it depends on where you are and what you're doing, what's the best material to use. And so concrete has opportunities for improvement, steel, wood, all of these materials, we need to be driving towards climate smart, smart, salutes.

solutions as we're building. And it's both the material choice who makes the material and how we configure and even what we build. The lowest carbon footprint building is one that we retrofit and reuse and maintain over long periods of time. Here you have it. Kate Simmons, Director of the Carbon Leadership Forum. Associate Professor of Architecture at the University of Washington, Jeremy Gregory, a civil and environmental engineering researcher, executive director of the Concrete Sustainability Hub at MIT. and special thanks to Martin Pay, CTO of European Steel Manufacture SSAB. We spoke with us earlier in the week.

One last thing before we go. Princeton, New Jersey listeners, Science Friday is hosting Science Goes to the Movies. Circle to your calendar Thursday, March 19th at the Princeton Garden Theater. Come watch this great sci-fi classic attic. Remember that? And then you can stay late for a special guest panel about the science behind the film. Go to ScienceFriety.com slash Princeton for tickets, science Friday.com

slash Princeton, March 19th, Princeton Garden Theater. Charles Berkwis is our director, produces our Alexa Lim, Christy Taylor, Katie Feather, engineering help from Rich Kim, Kevin Wolf, Lisa Gosselin,

B.J. Lineman, compose our theme music, and our Science Friday Vox Pop app. Help us get ready for our next degrees of change. Answer this question. Does climate change make you anxious or sad?

How do you deal with those feelings? Download our Science Friday Vox Pop app wherever you get your apps. We want to know how you're dealing with the climate change. Are you feeling anxious or sad? And how are you dealing with those feelings? I'm Ira Flato in New York.