2022 Festival of Science

Do you want the planet to be blue or red-hot? Climate change is already here: natural disasters, heatwaves, melting ice, rising waters... The environmental crisis is impacting our daily lives and our biodiversity. With the new IPCC report and the next COP 27 in Egypt, the climate and ecology are in the news. But do you know those who are leading the fight against climate change? Facing threats of a planetary upheaval, researchers and scientists are seeking solutions and taking action. To mark the 2022 Fête de la Science, we are putting the spotlight on them. Wherever you are in France, come and meet them, on October 7-17, 2022 in mainland France and November 10-27, 2022 in French overseas territories and internationally. This Fête de la Science will be an opportunity to bring generations together around the major issue of climate change. Come and meet our scientists, whatever your age! Let's talk about the climate. 

Hello. Is climate change inevitably leading to more frequent or severe natural disasters? In the years and decades to come, will we be more exposed to heat waves, forest fires and marine submersion? And above all, what solutions are available to limit these risks and adapt to them? We'll be talking with our guests from the BRGM on this show, which is airing live from the Grand Gallery of Evolution at the Natural History Museum in Paris. Here we go! To answer all these questions, I am joined by Gilles Grandjean. 

-Hello, Gilles. 

-Hello. Thanks for coming. Just before this broadcast, we heard you go a little bit into the subject we'll talk about. You are the director of a scientific program called "Natural Hazards "and Local Resilience." We'll talk about resilience, because after the facts, we need to talk about solutions. You work at the BRGM, the French geological survey. In my mind, the BRGM studies what's above and below the ground, but that's actually not all. You study all natural hazards. Yes. We have looked, since the institution was founded, at what's above and below ground. But it's a very complex, very varied environment. We use geology to try and understand it. There is also water underground, so we look at hydrogeology, water resources and water quality. The ground is also used to producegeothermal energy, so we also look at energy issues. And, of course, we look at the minerals underground in terms of resources. And the ground and underground are environments that interact with the biosphere. That's why we look at the natural risks this environment can pose to the way our societies live. OK. So we'll talk about the impact of climate change on natural hazards. We'll start with one you obviously study in depth at the BRGM. I won't say it just yet. We could sum it up with one word, or one name: Xynthia. You know it, but we asked our fellow citizens to find out if this mystery word brought back any memories. Let's listen. 

-Xynthia? 

-Yes. No, I don't know. A name, maybe. Or a plant. I don't know. I'm not sure, no. A tornado... A... A tsunami. A hurricane? I'm not sure. Yes, it was a storm. A storm in the Charentes. It destroyed everything, a whole town, a whole region. We're from central France, from Lyon. A lot of forests were damaged. There were floods, deaths, victims, flooded homes... Many people were out on the street. Houses were blown away or flooded, submerged by the water. The effect of the high tide plus the storm made it wash over them. As I recall, it was the first time that a residential area was abandoned due to the consequences of climate change. What do you think of that? It's not a poll, obviously. You can see it stuck with people. Everyone remembers the storm and the effect it had on homes, buildings and coastal flooding. Those are subjects we work on a lot. Valérie Masson 

-Delmotte talked about that earlier. Ocean levels are rising, at a rate that goes beyond what humans can counter by managing infrastructure. So that, plus tides, plus a hurricane that was born in the tropics and died on the Atlantic coast, led to a major coastal storm. For those who don't remember... It depends on the generation, because sometimes we forget natural disasters. This happened in 2010. Winds reached up to 200km/h. There were 23 deaths in France and many victims in towns that were submerged by the ocean. In La Faute-sur-Mer, in Vendée, there were 29 victims. There was a combination of events, it must be said. Scientifically, what happened? Yes. Currently... There is the rising sea level, which can rise more, for example, due to a high tidal coefficient... 

-Meaning a strong tide? 

-A strong tide, yes. There's also the fact that the weather event carries... It's a depression, as the name suggests. Yes, but you have to explain. We don't know. What does a depression do to the sea? A depression on the sea creates a local rise in the sea level, since there's less weight from the atmosphere pushing down the sea level. So the sea level rises. So that, plus the tide, plus the strong winds that created a very big swell caused what we call shipping water, which was able to pass over the dike protecting homes. Dikes even broke in some places. Yes. Given the strength of the waves, dams broke in some places, as you see there. Could this kind of marine submersion multiply or intensify with climate change? I think so. People now are well aware that the effects of climate change are beginning to be a part of their lives. We saw it this summer with droughts. We'll talk about that. But yes, we are expecting these events to become more intense and more frequent. They won't always happen in the same places, fortunately. But we expect to see these types of events on a regular basis. These kinds of events... You're not a meteorologist, but do they come from the Atlantic? Are they... Wasn't this the aftermath of a hurricane, for example? Yes. Hurricanes have a life cycle, so to speak. They're born in very warm water in the tropics, in the West Atlantic. We recently saw the effects of a hurricane in Florida. 

-Of course. Some of these large weather events move northward, driven by winds, and head to northern Europe. Fortunately, they lose their strength along the way, but they still come to die on our western European coasts. And if these hurricanes get stronger... The related phenomena will be more intense and more dangerous. Flooding is the biggest risk in mainland France, but there are several types of flooding. Some are linked to torrential rains. In 2020, we had the storm Alex, which had a disastrous impact in the Alpes 

-Maritimes. How do you explain what happened? That was another type of phenomenon that is... A few years ago, we called them Cévenol episodes, because they were very localized south of the Massif Central. Now we call them Mediterranean episodes. Does that mean the area is getting wider? Yes, and that's due to the rising temperatures in the Mediterranean Sea. It's a sobering thought that this summer, the inland sea broke all the temperature records. There was a heatwave in the sea itself. And in the fall, that warm air goes north to the south of France and meets cold air masses moving south, due to the change of season, from the north. That meeting of cold and warm air creates terrible thunderstorms. Another type of flooding we know less about is runoff flooding. Yes. We saw that in 2016, when it affected the Centre region, east of Paris and Paris, a little. That is due to very localized thunderstorms and the fact that the ground can get waterlogged at certain times of the year. Then rainwater can't seep into it, so it literally runs off. It runs through the whole watershed, and the further downstream it flows, the larger the water mass, and the greater the risk of flooding is for homes downstream. OK. You work at the BRGM. You're in Orleans. This summer, you suffered... I was even going to say as... What did you think as a resident, first of all? Were you surprised? 

-Yes, by a hailstorm. 

-Huge hailstones. Huge hailstones, the size of tennis balls. 

-Had you seen that before? 

-No. 

-Never? 

-Never. And as far as you remember, in Centre 

-Val de Loire? 

-No one had seen that? 

-Very rarely. It was a surprise. It was very sudden and fast. It caused a lot of damage to roofs and cars. OK. Is that also a risk... Is global warming contributing to these hailstorms? Can we say that? Yes, absolutely. The problem with global warming is that the overall warming of our planet is creating an energy build-up in the atmosphere and oceans, and that energy has to dissipate. And the way it dissipates is by confronting air masses. And those confrontations between air masses, cold air and warm air, create thunderstorms. The greater the contrast, the more violent the storm. How do we get hailstones as big as tennis balls? Because the clouds they come from are gigantic compared to what they were 50 or 100 years ago. Hailstones form high in the atmosphere. They take a long time to fall. And as they fall, hailstones clump together and create balls of ice that can become very large. Another thing we had this summer was forest fires. Forest fires, yes. 

-That's also... 

-Of course. Are they getting worse? Yes. It's a... It's a big problem, because drought dries out biomass. So the vegetation and trees are under severe water stress, and the amount of dried plant matter is much higher than when there is no drought. So a tiny spark can ignite trees, vegetation and undergrowth, because the plant matter is dry due to the water shortage. OK. And heatwaves. And heatwaves, of course. For the BRGM, that... It's quite a big risk. Fred, you said flooding was the biggest expense in terms of natural disasters for public authorities. The second is geotechnical drought. When soil that has a certain amount of clay content dries out, it contracts and decreases in volume. If a house is built on it, it will be affected by the change in the soil and crack. We never talked about this, but it will affect a lot of people. What do you call those movements? Shrink-swell. We're going to be hearing more and more about shrink-swell. Probably due to the drought this summer, yes. OK. Let's go back to marine submersions with an example of a French town that is already being forced to adapt: Miquelon. We'll discuss that specific case with a colleague of yours, a young researcher you wanted to invite. This is "Team Spirit." Hello, Xénia Philippenko. Hello. How are you? I'm fine. We went through the catalogue of disasters. It was important to explain them in order to understand how they happen. You're a PhD student at the BRGM and the physical geography laboratory. Yes. You're researching social and institutional adaptation to the coastal risks of climate change. Is it social science research? What kind of research is it? It's research in social science. I'm a geographer and I'm interested in perceptions of climate change and the acceptability of adaptation solutions, because once we have identified the risks, the question is: what do we do? How do we adapt? How are we going to implement solutions? Of course, people and institutions will have to face those questions, and it's not easy. That's what interests me. As we can see, Gilles, on the issue of climate change, every field and discipline, every kind of science, is overlapping and has to work together. They have to work together. We're doing multidisciplinary research projects, because to be able to apply adaptation strategies or make an area resilient, scientists can give advice and guidance and help make decisions, in some cases, but local stakeholders have to act on it. That's the whole problem with risk culture, which you know well, Fred, that will have to be solved in the future. Xénia, we'll talk about how it's perceived by decision-makers, who may need to be educated a little more. Xénia, you're looking particularly at the town of Miquelon. Let's look at the French archipelago of Saint-Pierre-et-Miquelon, in the North Atlantic, off the coast of Canada. Let's see it on a map. The town of Miquelon is located right on the water. Yes. It's located on a pebble ridge connecting two islands, the island on the north of the map, Le Cap, and Grande Miquelon to the south. The town was founded there, historically, because it's a fishing village. So... The fishermen settled as close as possible to their workplace, the sea. But it's a problem now because they are surrounded on both sides by the sea. And since the 2000s... How many people live there? 600 in Miquelon. 6,000 people live on the archipelago. It's a small population, but they're at risk. So this town, Miquelon, has been increasingly exposed to storms since the 2000s? Yes. We were talking about storms that come from hurricanes that land on the French coast. In Saint-Pierre-et-Miquelon, there is the same phenomenon, but they have even more tail ends of hurricanes, or tropical storms, which arrive... For example, they felt the aftermath of hurricanes that hit the Caribbean and Florida recently. And of course, there are more and more. These storms are becoming more intense and more frequent, so they're causing more and more damage. Is this town of Miquelon in danger of disappearing? Well, eventually, with the rising sea level, that's a concern, because as I said, it's a town that's right on the water. So they'll be the first to be affected by rising sea levels, on top of all the effects we've been talking about: surges, storms, etc. So for them, the question today is: where are we headed? 

-So they've decided... 

-Don't reveal everything. 

-I won't. 

-We'll... Don't reveal everything. You said "eventually." What does that mean to you? That's the big question. Even scientists don't have a definitive answer, because it depends on the situation we put ourselves in and the greenhouse gases we emit. The more we emit, the worse the situation will be. So it depends partly on that. Today, "eventually" is in the fairly long term. In other words, the town risks disappearing not in 20 or 30 years but more like 100 years. 

-But it has to adapt before. 

-Yes. Not at the last minute. What are people and elected officials in Miquelon doing to adapt and face the threat? That's what you went there to research. You'll tell us the story. You did a sociological study. Before you tell us about the choice and the decision made by the people there, we asked some fellow citizens, If the place where you live" was threatened and at risk, "would you be willing to move?" Let's hear some answers. I wouldn't be living there to begin with. I'd do my research first. If I found out, I'd move. It depends on the risk. In France, we're safe. If there was a polluting factory, yes, probably, but because of nature? I don't think so. I'd think twice before buying a house by the sea. I'd calculate where the sea will be in 2050 first. I would ask the public authorities to do something to stop the process. But if there were no solution and no choice, I'd do it. If it's constant, like the fires in California, yes. That would make me think, but for now, no. Moving means changing your life too. In Guadeloupe, we have seismic risks and more and more cyclones. So we're prepared. All we can do is protect ourselves. We're not going to move. It depends on what you call "moving." To a new neighborhood or a new city? If I lived by the sea and my house was going to be swallowed up, I'd have to leave. But if I didn't have to, I'd wait and see. That's how humans are. Until it happens, you hope it won't happen to you. You need to see global warming to believe it. I want to live in the mountains. That way, I hope I'll be safe. Is living in the mountains a good solution? There are risks there too. Yes, maybe from... We've seen that, with the risks of glaciers breaking off in the Dolomites, etc. What did you think of that? It wasn't a poll. But I saw you smile a few times. Yes, some of those answers make sense today, at least for me as a geographer. It's true that when you buy a house on the coast, by the sea, you should look at where it's located. What are the projections? Is there erosion? Storms? Submersion? But unless it is expressly prohibited, isn't there the temptation to go back... Earlier we were talking about Xynthia and La Faute-sur-Mer, where houses were completely engulfed. I'm exaggerating, but didn't people... Do you have any information about that? Did people want to go back to their homes? That's the most complicated thing. People have no regrets. The most emblematic example is the houses on the chalk cliffs in Normandy and northern France. We know the cliffs are retreating and we can't hold them back. The ocean will be stronger in the long term. So if a house is located right behind the cliff, there's no solution. We have to ask people to relocate somewhere else. They could move 3km away... Yes. ...and continue to enjoy the region, but at some point, you have to step away. This summer we saw campgrounds start relocating and moving back a bit from the coastline. Yes, exactly. That shows that strategies and adaptation policies are starting to be put in place and are being accepted. They're being put in place, which was not the case 10 years ago, when there was a lot of reluctance to change the zoning in a city because of a natural hazard. Awareness is growing in the right direction. Yes, fortunately. Back to Miquelon. What's happening today? What are residents doing? What choices have they made? When I started my thesis in Miquelon, we had been talking about climate change and coastal risks for a while. But there was a tricky issue there: the coastal risk prevention plan, a document that obliges towns to ban, among other things, construction in certain areas that are dangerous or threatened. This town is one, of course, so residents can't build anymore. What happens when you can't build anymore? What future do you have? So residents were pretty upset about the measure. Then in 2018, there was a storm. Like in France, where Xynthia was a kind of wake-up call and a shock, there was a storm in 2018 in Miquelon, with 180km per hour winds that caused flooding from high water table levels. The water didn't come from above but below. So homes flooded. 

-It caused... 

-A shock. A realization that this was going to affect them. So people decided not to wait but to act. They began a very dynamic, positive process. They decided to move the town to higher ground, somewhere near the original town but where they would be safer. And rebuild it? Yes. It raises many questions. Do you rebuild everything from A to Z? What do you do with the old homes? It's a place where people are very attached to their history, culture, heritage, and especially buildings. What do you do with those homes? Do you move them from the old town to the new town? Yes. It's... If they're fishermen, they can't be too far from the sea. On an archipelago, the sea is never far away. That's true. But yes, they can't be too far away, though the economy is no longer only based on fishing. So they made the decision to move? Yes. They've already started the process. At the beginning, in the first stage, I asked them which solution they preferred. I was surprised to learn that 89% of them were in favor of gradually moving the town, even though they hoped they could protect the current town as long as possible, understandably. Gilles, you talk a lot about resilience. What is it? There are many definitions in different scientific communities, whether it's geographers, risk engineers, etc. But in general, it's a human system's ability to face a series of crises and each time overcome them, because they learn along the way to react to the crises... Is it adaptation? Yes, it's a kind of adaptation. It's really finding societal and economic functions that won't always be endangered by successive crises. Among the adaptation strategies we often hear about are nature-based solutions, or NBS. Do you have any specific examples? What are NBS? The BRGM has worked a lot on nature-based solutions in two environments: coasts and mountains. On coasts, we have some very good partnerships, like with the ONF. For example, to keep dunes from moving too much, like due to winds, and taking with them sand that is needed to manage coastal erosion, we are testing replanting solutions that will allow plants to keep the dune in the same place. That's one way of doing it, rather than putting in dikes and concrete or retaining walls, for example. In the mountains, it could mean widening the floodplain to make room for the river when it floods so it stops eroding the banks and causing landslides on adjacent mountain slopes. Those are just a few examples of nature-based solutions. They're common sense. Using today's scientific knowledge. Yes, because it requires doing studies to see if the solution will be sustainable. You have to study it and then nature does its job. Yes, but the work you do as a scientist must be known to decision-makers, because they're the ones who will say, We don't need a dam but to work" "with the trees and the sand dunes." They need that knowledge. You need to share that knowledge and be heard. Yes. That's why, in our research projects, we're increasingly including specialists like sociologists, who will allow us to interact with those stakeholders, with elected officials, citizens and organizations, and bring them into a project. The idea is to get them on board and engage them from the start so they understand the problem, to get them to change and participate in implementing a solution. Are things changing? You said everyone has become more aware in the last 10 years. Are things changing? Yes. Well... The research projects I follow show that there's more and more permeation, or collaboration. We're co-constructing solutions. It's happening more and more, yes. So you're working with decision-makers and citizens. Participatory science is important to you. You do that a lot at the BRGM. I've seen something great on the coast. You put your smartphone on a stand. Maybe we can see some pictures. It's called... 

-It's called... 

-SnapCoast. Yes. Tell us about it. It's an idea that originally came from Australia. We install stands on parts of the coastline suffering from erosion and ask citizens to place their phone on the stand, take a picture and scan the QR Code next to it to send the photo to a server. It doesn't take much effort from people, but they're participating in the study. And for scientists, it's a way to measure changes in the coastline with lots of data and observations. So it's very useful. You have to encourage people. As citizens, it forces us to ask ourselves questions. We wonder why we're being asked to take a photo. Let's end with the SAMCO project. Does that name ring any bells? SAMCO, yes. It was a project funded by the French National Research Agency where we tried to study, in a number of Pyrenean and Alpine valleys, what the risk could be in the distant future, as Xénia said, like in 2100. That meant choosing climate scenarios based on more or less severe global warming. But the risk is not just the hazard or the weather phenomenon. It's also the challenges. We had to know how the valley could change by 2100, so we co-constructed it with valley residents. It enabled us to produce predictive maps based on whether the valley's citizens and local authorities pictured a more industrial, tourism or agropastoral future for their valley, and to compare the resulting risk maps. OK. For citizens, a very important site that the BRGM contributes a lot to is Géorisques, which is slowly expanding to cover everyone, so they know the environment they're living in. It's really important. So visit Géorisques. Time flies, and it's already the end of this program. Xénia, thank you very much. Thank you both. Thank you, Gilles, for being with us. Good luck in the future. We'll try to help you too, with your research. Thank you for watching. We'll see you soon on another show about climate change and the solutions we can try to find today to change things. See you soon. 

BRGM AMBASSADOR WHAT IS THE FÊTE DE LA SCIENCE TO YOU? 

The Fête de la Science is a chance for scientists and civil society to come together. I think it's important for people to understand what researchers do in laboratories and research institutions. It's also an opportunity to meet young people and spark an interest in our careers. 

CAN YOU SUM UP YOUR JOB IN ONE SENTENCE? 

As a Scientific Director, it's my job to explore research related to natural hazards and organize that research into research groups within my institution, and then to promote their work so that all the benefits can filter down to civil society. 

SHOULD WE BE WORRIED ABOUT THE CLIMATE?

That's a big question. The latest IPCC report mentions a growth in the intensity and frequency of weather patterns. Of course that has an impact on climate-related risks, and we do expect in the near future to have more flood-related disasters along coastlines, along with hailstorms and landslides. 

ANY STORIES TO SHARE?

It's more something I saw. When you see a disaster firsthand, you really get a sense of it. I have a vivid memory of the 2016 floods in the Loiret region, close to BRGM, where, due to oversaturation of the soil, several houses collapsed into the karstic cavities below. That's something that sticks in a researcher's memory.