speaker-1: Hello and welcome to Local Zero, the Strathclyde Institute for Sustainable Communities podcast. I'm Gem Roberts.
speaker-2: I'm Matt Hanan and today we'll be discussing climate hazards.
speaker-1: Our climate is changing fast. Climate risks are becoming more frequent and more severe and new risks are beginning to emerge as well. But what happens when multiple climate hazards occur in the same place and time? Or what happens when they occur in close succession?
speaker-2: And how common are multiple climate hazards or climate hazards stacking for short? And how might it change as climate extremes become more pronounced? What does it mean for climate adaptation and what changes are needed to support resilient communities and a climate resilient society?
speaker-1: Now to explore these questions, we're joined by Chris White, professor in climate extremes and resilience at the University of Strathclyde and an expert in multi-hazard risks across system and society. Longtime listeners will know we've been super keen to have Chris on the podcast for really quite some time. And so we're delighted that the stars have finally aligned.
speaker-2: But before we get into the discussion, a quick reminder to follow Local Zero on LinkedIn to stay up to date with the podcast and share your feedback and suggestions. Just search for Local Zero podcast.
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speaker-2: if you wanted to do this episode for quite a while about multiple climate hazards, hazard stacking, whatever you want to call it. This is about climate change when the rubber really hits the road and not just one problem emerges, not just two, but many, many interlocking, I want to say complementary issues. And what I mean by that is that they can kind of amplify and make things worse. And we're saying this, right? As, I feel like we're saying this all the time, but. This coming week, we're expecting record breaking heat again. London forecasts 40 degree heat in the next couple of days. You're just back from Barcelona. Was it even that hot there?
speaker-1: No, it was lovely. But you know what, yesterday and the weekend I spent cycling around, ⁓ you know, the Dunoon and Bute, the kind of the Argyll and Bute area in Scotland and on the ferry back over, everyone was talking about how it was just too hot, too hot. And I did ask a couple of people how hot was it because I'd been on my bike, I didn't have any stats or in fact, everything, all my batteries and everything had died. And it was only this morning that I found out it was 24 degrees. And it made me laugh a little bit because I was like, in 24 degrees, basically in Scotland, we have a catastrophic meltdown and everybody can't cope. It's too hot, we all proclaim. In Barcelona, it didn't feel, it was about that warm. It didn't feel anywhere near as much partly because I was probably expecting it and ready for it and prepared for it. And that's one of the things that we're going to be probably talking about today as well is how to prepare for these sorts of conditions.
speaker-2: And whether you can, right? Whether you can prepare for 40 degree heat in a country, in a built environment, a populace that really isn't familiar with these heat extremes. And as I say, it doesn't have the infrastructure, the technology, even just the cultural kind of practices and know-how of how to deal with this. Even just like what we dress and where we work. this comes, this record-breaking heat this coming week hasn't happened as we are. as we're recording, but the expectations are a Met Office red warning has just been issued for pretty much all of central southern England. And this comes hot on the heel of a report from UNICEF, which spoke to how half of the world's children are exposed to at least three climate hazards. Now, what kind of hazards are we talking about? These are heat waves, storms, floods, droughts, you name it. know, it's fires, it's sand and dust storms. Half of the world's kids. And this was the stat from that report that really blew my mind. They expect that 123,000 children, I'm assuming this is in during their childhood, not lifetime, will experience more than six of these hazards. Six. They experience the whole lot. That's not an insignificant number of people.
speaker-1: It's not, and it is worth remembering and maybe reminding people that young people are a vulnerable category. So when we're about heat waves, those particularly vulnerable in heat waves are the young and the elderly. So it's not that this isn't, you know, it's not okay anyway, but it's extra not okay when we're talking about the extremely vulnerable. And to be fair, probably that statistic around half world's children, I wonder how that translates into half the world's elderly, however you define that cut off exactly. And think it is also worth, know, when we both were talking about that report when it first came out, the fact that actually it's almost every child, including those from high income countries, is exposed to at least one hazard. So this is affecting everybody and everyone is at risk. And I think that's important. It's important to let that.
speaker-2: And I think it's worth unpacking why we're talking about multi hazards now. if I maybe let's just do this sort of very academic thing, let's list the hazards, right? So we know what we're talking about here. So the UNICEF report, coastal floods, droughts, extreme heat, fires, heat waves, river floods, sand and dust storms and tropical storms. Now, what we're saying is it's not just one of these. It's not just a drought or a forest fire or a flood. It's the fact that these things can all happen. in and around the same time in the same place. Now we're maybe getting into some bigger kind of theoretical concepts around complexity theory systems thinking this idea of where you're trying to connect different causes or causal factors and impacts, but actually they can amplify each other and make things a damn sight worse. So Jen, it was your inspiration, I think, speaking to Chris, a colleague of ours, about to take this on, but why should we be talking about multi hazards and this notion of kind of stacking or... or has it amplifying on
speaker-1: Yeah, well that's what we're gonna get a chance to talk about that today. And I know it's been sort of circling around with we've discussed before about climate adaptation ⁓ on the pod. And we've discussed these different types of climate hazards or climate risks and some of the terminology I think we're gonna be able to get into with Chris today, because I think he'll keep us right as well. We're not the experts. But here we're starting to learn more about what happens when these things happen either in close succession or at the same time. And I think also some of the things we've been exploring on the pod is how you define these sorts of hazards and how localized they can be. So we've had so many questions ourselves. I know that we've talked about it when recording and not recording. ⁓ Just to understand this a little bit more and to understand how how they're encapsulated, but also how well these event series are understood, how well they're catered for and to how prepared.
speaker-2: how well they're communicated. How do you communicate these hazards? I was just said we've got a red warning from the MET, okay? But that doesn't capture necessarily some of the hazards we're talking about here, drought, fire, flood, and nor does it communicate what impacts they will have, right? Because it could, for instance, could knock out a power station, you know, or you might disable the East or West Coast mainline in terms of rail or your local hospitals unable to function because people can't get to work. That's crazy hard to articulate that, but ultimately that's where we've got to get to because I think most of the time, I think people can just about bend their head around a single hazard and what that might do. I still don't think that it means they could be prepared. If there was a forest fire approaching my house, I'd have no frame of reference whatsoever to that, right? But at least I could kind of imagine that. What I couldn't imagine is the sequencing or connectivity between that and a whole host of other natural hazards. and the implications they have. I think until people recognize that and can kind of, I don't know, conceptualize that, how can we start to act against the true costs of climate change?
speaker-1: And I think also to consider with whom is the responsibility to act. And there will never be one singular person, but know, it comes to things like the West Coast mainline not operating. It's very clear that's Network Rail and the West Coast mainline that are responsible for that. When it comes to other aspects of responsibility, you know, it's that communication piece and that kind of preparation piece becomes extra, extra valuable and important.
speaker-2: And it comes back to this notion of resilience, bit of a of a contested term in some senses. ultimately, when things start falling apart around you and those organizations or authorities who are normally responsible for, you know, keeping whatever it is, healthcare or electricity, whatever it is, whatever these critical services are, there's also something else you've got to fall back on. And I do think there's a really interesting question here about the role and relative importance of community resilience in terms of managing these. Because at what point do you need to turn to your neighbor and vice versa? At what point do you need to have this kind of safety net? And you see this when you and I travel to not just across the UK, but particularly when you're in the highlands and islands, you see a sense of resilience. You just don't get in suburbia because you know,
speaker-1: You don't see so often in suburbia, perhaps. It definitely exists. You're right. I think the other thing that's really interesting to explore here with that definition of sustainable communities is that that typically requires living within planetary boundaries and safe planetary limits. And we understand now that we have overshot various planetary boundaries and various planetary limits. So there is perhaps, I mean, we're putting maybe a bit too much on our conversation with Chris today. I suspect this will cascade.
speaker-2: He'll have all the answers, worry.
speaker-1: I think this will come up again in future episodes around, is it even possible to have a climate resilient, sustainable community given the context of operating within planetary boundaries and how many of those have been overshot or broken down?
speaker-2: Yeah, because it's almost like that those natural capital stocks and the ecosystem services they provide are your way of riding out the bumps in the road. But if you've actually, if the climate is ravaged, you if it just destroys your crops or dries up the river, then how do you move through that? So yeah, I guess what I want to also say is that I don't want people to be listening to this. I'll just turn this off. This sounds extremely depressing. And, you know, I think there was a point just pure pragmatist standpoint for me is that We need to be able to connect these, because we need to understand what five, 10, 15, 20 years looks like in order to start planning for this stuff. you know, unless you're going to shuffle off this mortal call pretty quickly, you should even just from an individual standpoint care about this. for friends, loved ones, it is about how we start making this preparedness. And it's about policy decisions from Westminster, Whitehall, Holyrood, Brussels. These decisions matter. And I honestly think we're still looking at stuff through the lens of individual singular hazards. Exactly, his perspective hopefully will be able to connect the dots for me.
speaker-1: So this is what we'll find this out. connect the dots and also with all of this, climate is incredibly uncertain and climate projections is those that we can have confidence and full confidence in some statements and probabilities, but less confidence in others. And so I think also getting a handle of, actually, how much do we know about this already? We've got numbers and narrative equals change, right? So first of all, what do we know? And then that narrative of what, okay, what do we do with this? ⁓ I agree, For listeners who are thinking this might be also extremely academic and very jargon based, we're gonna do our best to bust the jargon and do our best to also really unravel not just what's the current knowledge and state of the art, but also what's next for this area of work and policy and then bringing it back down to our everyday lives. Everything we're about at Local Zero Podcast is climate action at the local level. So what does this mean for you, me? those around us, those elsewhere. What does it mean for those on the ground?
speaker-2: Yeah, and the bigger picture, 100%.
speaker-1: Yeah, right. think we might need like three hours with Chris. So should we bring him in? Yeah, let's started.
speaker-0: I'm Chris White. I'm a professor of climate extremes and resilience at the University of Strathclyde in Glasgow. I study extreme weather phenomena and how that interacts and affects our society and in particular our critical national infrastructure.
speaker-1: So Chris, we should probably start by acknowledging and maybe letting our listeners know that we do work together and we are in the same department in fact.
speaker-0: We are indeed. It's a bit of an inside job today.
speaker-1: Indeed. However, I mean, we've been working on a couple of things together. I know we've got a few more irons in the fire and ideas, but lamentably, I would say we've never had a specific conversation around your work and exactly what you do. I'd love to say that I've been saving that for the pod for the last 12 months or however long we've been trying to get you on the pod and trying to get our dates to align. But to be honest, I'm really excited to find out a bit more about exactly what you do and some of the terminology actually. How about I ask the most basic question to start with? What actually is climate risk and what's climate hazard? I think that'd be really helpful for us to get a good baseline on that before we go any further today.
speaker-0: Thanks. I think it's a perfect place to start. And isn't it funny that we interact all the time really with each other and yet do we have time to actually discuss what do you do and how do we do it? So this is a perfect opportunity. right. I'll try and unpack it a little bit. I want to start, if I could, with what's a hazard? I know that's really straightforward, but a hazard is really the centerpiece of what the sort of work that I do. A hazard in this context and... work I do is something that's driven by weather or climate. So a flood or a storm or a heat wave, that's the hazard. Something hazardous, something that is likely to cause an impact. So when you put the words climate and hazard together, that's really what that means. It just means an artefact of extreme weather probably that we can experience and that could cause us some level of impact. But the other half of that, or the other part to that is the risk bit. And risk, course, is a very difficult thing to quantify. We all do it all the time. We all make our own assumptions and risk assessments. Do I take an umbrella out on the basis of what the weather forecast says today? We're all doing our own level of trying to understand risk. But from a science perspective, risk has quite a specific definition. And risk is actually a three-way equation, three ways for discussion really that goes between a hazard. as I said a moment ago, that's the flood, the drought, the storm. But there's two other components to that which is in a very formal way is exposure and vulnerability. And there is important that you have to look when you're thinking of risk of all three of those together. So exposure is what's exposed, what is in harm's way. There might be something physical like a bridge or electricity pylon or a train line. It could also, of course, be people. And often when we're dealing with climate risk, really we're interested in people, keeping people out of harm's way and not impacted. So exposure is something that could be affected by the hazard. And then the third bit is the vulnerability. And that's the most intangible, actually the most difficult part of that risk. equation or triangle really as it tends to get represented, which is how susceptible is someone or something to those two other components. And it means then risk is a very dynamic thing. It always shifts and changes. You'll have a different, one event can affect different people in a variety of different ways. So when I tend to use the term climate risk or climate hazard, I'm probably blending the two together, but really I'm in a very general sense trying to understand What drives our weather? What are the hazards that come from weather and in particular a changing climate? And then how can it affect us, our way of life, our transport, our networks? And what can we do to be more prepared and more resilient to those types of phenomena?
speaker-1: Amazing. Yeah, that's super helpful. Thank you. I think then what I know that you're an expert in is in compounding and cascading hazards. And you just talked about, you know, blurring sometimes the phrases together. I was made aware that I've completely made up a new phrase, which is climate hazard stacking that Matt and I are now very happily using because to
speaker-2: TM copyright, that's, you heard it here first. It's inside scoop.
speaker-0: On the back of this, I think I'm going to go and write a paper using that exact term because I haven't seen it before and it's quite neat.
speaker-2: You could come on as a second or third author, Chris. That's absolutely fine.
speaker-1: Honestly, to me, it conceptually, I think makes sense of what it is that you work on. But I don't know that actually, because we've never had this conversation. I've invited you on the podcast to understand your work more. So would you be able to tell us a little bit about like, is a compounding or cascading? it be hazards, compounding hazards? What is it exactly? Just expand on what you do.
speaker-0: Okay, all right. So, ⁓ yeah, we're getting into the territory of lots of definitions, often meaning again the same sort of thing, and it gets a bit complicated. I'll try and break it down as really simply and as easy as possible. we tend to think of things quite singularly and often in silos. So take, for example, a flood. We know that a flood can be caused by variety of things, riverine floods, rivers going out of bank and flooding surrounding areas. can be heavy rainfall on flat or impermeable surfaces causing surface water flooding, can be flash flooding, it's all sorts of types of flooding. But ultimately they all sit in the realm of hydrology. Now hydrology is one subset of a broader climate piece or climate discipline. But we tend to think of things in that kind of singular way because it's easy to understand, it's easier to manage, it's easier to communicate if you're talking about something singularly. But the real world doesn't think of things in that way. It doesn't just think about a flood. It doesn't just think about a storm. Often they interplay and interact with each other. And a storm actually is a really good example of that. So a storm can have a variety of different phenomena attached to it, but Typically it might be high winds, heavy rainfall, high likelihood of flooding of one type or another, coastal inundation perhaps, or surface water flooding. So the space that I tend to work in, I won't use the word expert, that's your words, but the space that I work in is actually trying to bring that reality into the understanding, the modeling, and the predictions of the climate hazard and risk space, which is recognizing that many things connect with other things. So let's look at it firstly perhaps then from the hazard perspective. Hazards can interact with each other in so many different ways. So I just mentioned storms there. Storms I think is a really good example because almost by definition they have different components to it. But think about other types of events that we see, say a drought. A drought we will probably tend to think of as from how it affects us. We don't have much enough water, so water shortages. But a drought from a hazard perspective actually needs a combination of lots of different things. It needs typically past low levels of rainfall over a period of time. The water in the soil, soil moisture, needs to be somewhat depleted. Past river flows, low. And of course, increasing demands. There's lots of dynamics in there as to what a definition of a drought is. So again, the sort of work that I try and do tries to look at it actually from the real system perspective is recognizing that these hazards don't typically they don't happen in isolation. They aren't single things. But it expands one step beyond that though. That's things that perhaps might co-occur at the same time or the same place. Even more tricky are events that happen perhaps in sequence. Something that happens and then something else or something that might trigger something else happening. So let's start actually with the second one of those two, the triggering one. We've seen global ins and in so many places we have really extreme rainfall. will then increase the likelihood of landslides. Landslides, of course, can be deadly in parts of world. They're very susceptible to landslides. Two fundamentally different mechanisms. A landslide, of course, has to have the right conditions, let's say, for a landslide to occur. So saturated soils, so the ground's going to be really wet, and of course, it's going to have a steep slope for a landslide to occur. But that wouldn't occur without the rainfall part of it, perhaps. but they're often again thought about in different ways. One's in that geological space, one's in the hydrological, meteorological space. So the sequencing part there, the timing and how things might occur one after another or trigger something become really important. And I think in the last 10, 15 years or so, there's just been this increasing recognition that if we are really to... to really tackle the challenges that we are facing very rapidly from climate change is we have got to move ourselves out of thinking about things in the singular, a flood or a storm. And actually we need to think how are we experiencing these events and how are we going to experience these events far more in the future. So I can give a good example, a very recent example of these interactions between hazards We're going have to think back to 2022, where we had the really extreme temperatures, particularly in the southeast and around London. And we saw for the first time 40 degrees in the UK, for someone like myself who's been studying climate for longer now than I want to perhaps recognize, the idea of having 40 degrees in the UK felt like middle of the century, end of the century type stuff. of course, suddenly 2022, 40 degrees in London. Now that was predominantly, as it was forecast, a heat event. It's all about the temperature, super high extreme temperatures and the effect on perhaps infrastructure, how that might affect transport and power. And of course, from a human health perspective, how it affects us, people that are vulnerable to temperatures. But some of the most significant impacts that happened during that event, of course, were the temperature, but was also the accompanying wildfires that came with them. And it was that part, that interaction between not just one hazard, but now a multiple set of hazards that really caused certainly some of the most visceral ⁓ visual impacts that we saw from that event. You can't see a heat wave, you can obviously experience it, you can't see it. a wildfire and a wildfire on the urban fringe in and around London. If you want a powerful message of what climate change is and what it's bringing, that's it. ⁓
speaker-2: you got goosebumps from what you're referring to because I remember seeing it was one of those moments as certain things I remember seeing on TV twin towers one Japanese tsunami and then I remember vividly 2022 because I remember Dagenham being in on the news and there was wildfire that kind of swept through and I was just a discombobulated because I'm seeing this and these houses had just been raised these cars that were on flames it was an aerial shot And I just assumed I was looking at California until I realized these were kind of post-war 1950s kind of semi-houses, the little white plastic furniture in the guard, Vauxhall Corsa on the driveway in flames. It's like, this isn't California. This is the Southeast of England. And you're quite right. We're into new territory. So I think this then brings me onto my question, which is this notion of multi-hazards or hazard stacking or hazard cascading. Chris, is this something that's... I don't want say new, but is it much more popular as an area of research or more generally, is it something that practitioners are coming to you with, with concerns and saying, look, for whatever reason, you know, it be an insurance company, might be ⁓ somebody putting on a major event like Glastonbury or Wimbledon or whatever it is, we need to get on top of this so we are prepared for all eventualities. So two questions in that, is this a kind of a new or more... popular phenomenon and to who's coming to you with these questions.
speaker-0: So two really good questions in there. The new part, maybe there's a subtle sub-question in there actually, which is, are these types of events different? Is a multi-hazard event fundamentally different to a single hazard event? And actually, I'm going to answer my own question. No, they're not. We're very good at creating terms, new terms, new scientific terms, that might often mean the same thing. So they're not new per se. The new part is the recognition that we need to be thinking about hazards in that more complex, interconnected, real world way. That's the new bit. over the last, I would say 20 years or so, there's been certainly the last 15 a movement from just thinking about things generally speaking in that single way through to No, we need to be thinking about these in a more real world system kind of way. And events like the 2022 heat wave fires are a very good example of exactly why. That caught everyone largely by surprise, I think. The temperatures were well forecast, the fires less so, and it was known that there was a high chance. But the fact that the London Fire Brigade was overwhelmed on that day. and it's had its busiest day since World War II, is enough of a wake up to say we have to be fundamentally rethinking how we deal with these types of events because we often feel like I'm at such an air of negativity when I'm talking about my work. But the reality of our future is actually what we're seeing now. As we're recording this podcast today, it's the The first day of amber and tomorrow will be red weather warning for London for again very similar temperatures that were forecast for 2022. We could easily see conditions that are either ready for fires and certainly for super high temperatures. But this is a month earlier in the year, the calendar year from the 22nd year. We're in June, not July.
speaker-2: Which kind of organizations might be reaching out to you or colleagues now or what I'm trying to get at is who, and Jen made this point in the kick around, who is responsible for managing these risks? And that is a massive, massive question, because it totally depends on which sector and which region you're in, but who is having to come to terms with the multitude and the connectivity between these hazards? And I'm hoping you're not going to say nobody. Because that would be-
speaker-1: Everybody.
speaker-2: Or everybody, yeah.
speaker-0: I was about to say what Jen just said, which is everybody. Perhaps I can find a middle ground in there, which is it should be everybody. I'll explain what I mean. I'm an engineer. Jen and I are in a civil engineering department. I did civil engineering as a background. So a lot of my work is actually about translating this sort of work or this sort of science, actually often through an engineering context. So I use the words of critical infrastructure. So at the beginning, Critical infrastructure to me is our built environment, power networks, transport, roads, water supply. I tend to think about the things that we rely on and that connect us actually. So that's what everyone would mean by critical infrastructure. So therefore it means a lot of the people that I tend to work with, or I think you use the words, who comes calling on me for advice or research, it's... probably typically critical infrastructure owners, but that's more of a product or an artifact of who I am and where I work. The reason I said everybody, everyone's responsible. If you expand that to us, us now as people, everyone as people, communities, we'll live on streets and roads and in houses, in towns and cities and villages. Yes, we all rely on critical infrastructure and it's a good way of analyzing this from a large scale. perspective. But the everybody bit comes into, think, increasingly, we all have a responsibility or increasing recognition that we have a responsibility to prepare ourselves for these types of events. Now that puts a lot of emphasis and onus on us to be aware. And I'd like to think that some of the work, little bit of the work that I do helps to raise awareness of the challenges, but also hopefully trying to provide at least a an idea of what some of those solutions are. And I can reference Australia as a really good example of this. I have an Australian passport, so I can put my Australian hat on now at this point and say culturally, it's just one example of a country, but culturally hazards are very upfront in Australian society. It's just that sort of country because it's exposed to pretty much every climate and weather hazard and more that you could possibly think of. And so it's a tough country. And so to survive, think, as a society, as a culture, it's ingrained that self-reliance and that preparedness in the culture. So everyone, or at least so many people I knew, everyone had a bushfire plan. Everyone knew what to do with a flood when a flood occurs. Everyone knows that there's a body responsible, the state emergency services typically, that deals with that and helps in the preparedness and the response side. Now bring that back to the UK. We don't have that connection. We don't have that awareness. I think we are in that sort of way of thinking of someone's going to come to our help. Someone's going to tell us when I need to do this, or someone's going to clean up and mop up afterwards, or it's going to build that road better or move that train line to a different place because of it. And the reality is... Yes and no. Yes, some of that is happening and will happen and the movement for more resilient infrastructure, yes. But I think we all have a part to play in building that resilience, that self-resilience to these types of events because again, I'm going to sound very negative, it's not going away anytime soon.
speaker-1: Yeah, I was thinking actually in this run of warm weather or hot or over hot weather that we've had recently, I have shared on an episode from the Local Zero Pod around adapting our homes to climate because in that it had some really specific actionable nuggets of information around how to keep your house or your flat or your office cool. And I was sharing it on not to lecture or to promote the pod, but actually just to be like, guys, you might be interested in this because of the conversation that you've been having. And I was thinking that because there is this cultural, this expectation that there's kind of lack of awareness of proactive action, actually taking responsibility, but also being proactive in reducing the risk of something. And this loops me back around to something I'm really interested about. You touched on earlier. around the wildfires that came with that, 2022 heat wave. that's, know, are we talking now about natural hazards? Often we think about flooding and fight. We think we use the word natural hazards. My background is in earth science, environmental science. And we talk about natural hazards. We always think about earthquakes, volcanoes and so on. I think there's something really interesting here when we talk about climate change. The probabilities have become a lot much. much higher on experiencing these due to climate change. Are these still natural hazards or are they not natural? And this is a very long way of asking that question, but if we link back to that issue with fires in and wildfires in London, how much of those wildfires were, you could really come down to human behaviour or were they wildfires that were instigated naturally? Were they natural hazards? Were they manmade? or is it a bit in between and does maybe our classification of hazards need to change a bit?
speaker-0: wrapped up in there was a really good question.
speaker-1: I'm so
speaker-0: I suppose by definition, floods are going to occur, heat waves are going to occur, no matter what we do or don't do. Hence the term ⁓ natural hazards is a term that's been used for quite a long time. The climate part to that, the climate change part, then changes the likelihood of something happening, or past the severity of something happening. So often after big events, there's an analysis done, there's a couple of scientific groups out there that do what are called attribution studies. How much of this event was caused by climate change? That component that says, well, this event was now three times more likely because of climate change, as in what we have done. Does that then change it from a natural to a non-natural hazard? No, not really, because it's still a flood or a a storm, it just has changed the likelihood. So then to go back to the bit I had at the beginning, the risk triangle of hazard, exposure, vulnerability, it just means it shifts the likelihood of those things occurring a little bit, or it just changes the dynamic. You might have the same amount of people or exposure, but now suddenly we've got a heightened risk, likelihood. ⁓
speaker-2: Chris, we've talked about multi hazards, this new seminal term, hazard stacking. But you also, I think, made reference to hazard cascading. And I wondered whether we're talking about something different here.
speaker-0: Yeah, we are and we're not. Again, science loves a good term and likes to distinguish, to make it possible to calculate things and make estimations. But the cascade in this context has quite a particular meaning. So hazards can trigger each other. So that's the kind of physical interactions between hazards, how something might affect something, maybe make something more severe. But the cascade part actually talks a bit more to the risk side of things, which is how the impacts or how the risk really propagates through our interconnections. And that sounds very abstract but I'll try and make it bit simpler. take the London Heathrow power outage that happened in 2025. Not driven by a climate event in this case, it was a substation that lost power. Now in theory that should have been a single event lose that source of power, Heathrow would have switched over to one of its other two sources of power, no problem. But what happened is there was a knock-on series of effects, a cascade of impacts. One thing triggered something else, and before Heathrow knew it, then at that point they lost power. They had no option to regain power in a quick space of time. And so the impacts, of course, at that point, direct impacts were significant. You lose ⁓ a national, international airport the size of Heathrow. that has significant impacts for people trying to fly. But then of course you can go further out again. All of the supply chains, the people trying to get to the airport, the transport networks that are all relying on that airport operating. That type of event was a significant event for Heathrow and of course the surrounding area and people travelling. That's a good example, let's say, of a cascade. A cascade of impacts something. that affects something else. Sometimes those impacts can be quite intangible actually. They can be disruption. How do you quantify disruption? It can be really challenging versus say something that is very obvious. A house burns down or a bridge is taken out by a flood. That's the direct part. The cascade risk or cascading risk or impacts moves as my area of work, which is that understanding of multi-hazards, very much then into the risk and impact space. And now we really are talking about real world because we all live in a very interconnected world, increasingly so, of course, with communications and digital networks and reliance on everything working and just on time type of deliveries. Cascades then can be really disruptive. You have one thing that takes something out, has a knock-on effect and it has a much larger problem. in there, there's been work, we've done bits and pieces of this, but in there, there's work that shows that certainly from an infrastructure perspective, of course, it's power. It's electricity, communications as well, but it's power that is that centerpiece. If you lose power, ⁓ the likelihood of impacts going from, let's say, local scale too much broader city-wide, nationwide potentially scale of impacts. We saw Spain and Portugal lose power for a couple of days. Again, not climate related, but we saw that in also 2025. That's whole countries losing the ability to have power. And then think about all the knock-on effects of that. So cascade in the work that I do is trying to make those... those connections. So if my work wasn't complex enough trying to understand the physical interactions between the phenomena and how that impacts us, it's even more complicated when you're starting to bring in the cascade and the interdependencies between our systems and our networks.
speaker-1: How well, so that, mean, yeah, can say, mean, my head's already starting to hurt a little bit, but how well understood or how well handled are these multiple or cascading risks? It actually makes me think of our colleagues in management science thinking kind of operational safety and things like that. Are these things that actually, know, the science is pretty well known, maybe the models handle this very well, maybe they don't, maybe that's. you need to work on. Where is the of the main uncertainties at the moment or the direction of travel for your work? Is it in that understanding the risks of these or is it about managing those or understanding those cascading risks?
speaker-0: I hate to answer on this, but it's both of those two, actually. think people are trying to tackle that challenge from both perspectives. So we can go back to the last couple of UK climate risk assessments. The climate change committee every three to four years do an independent study. They assess risk and then they basically provide that to the government for the government to make an informed decision on where climate risks sit. And over the last couple of iterations of that, it's recognised that cascading risk is a real blind spot, a real area that everyone knows is a high risk. We see more and more events that are re-highlighting those risks, but we haven't really got to grips with it yet. And so it's being tackled from two ways, right? One is of course that recognition and the potential, how do we manage them? But to get to that point, actually, and this is perhaps where it becomes more of a semi-research type of activity is, How do we evidence them? How do we know what these interconnections are? Even the simple thing of what's the evidence of them? So I'm an academic, and I love data and analyzing data. But imagine trying to map a whole system of infrastructure owner-operators, all with their own interests, their own reasons for being. Take a water system versus a power system. or a telecommunication system. They're all there to do the job that they're supposed to do, but they're not really there to understand how does this piece of infrastructure connect to that piece of infrastructure and is it relying on this? They're not built in that way. mean, half of our infrastructure is built in the Victorian time. yeah, they're not wired in that way. So a big... gap, a big area of open research, and this is probably what I'm spending most of my time at the moment, is actually working with, say, critical infrastructure owner-operators to help to understand and map not so much where their assets are, but where those dependencies are. Where are the critical points in the system? Where are the weak bits? This comes back to that risk exposure of vulnerability. Where are the weak bits in there? Where are the most susceptible? So when something like a heat wave and perhaps the potential for a fire occurs, where the likely impact's going to be, and if something did impact that area, what would be the knock-on effect? So if you lose power in one place or you lose water in another, then what would that affect? Again, to come back to the 2022 example, here we saw the water pressure was low. People were running out of water. How do you fight a fire if you don't have water? Now two completely different pieces of infrastructure or mechanisms but heavily reliant of course on each other.
speaker-2: So on that point about managing these risks, in your mind, this maybe goes beyond some of your research, but it will certainly speak to how people use your research and others. What are some of the challenges in actually taking forward this evidence and implementing solutions or strategies to manage these risks? You know, there are so many times when you'll hear, let's take more broadly about environmental externalities. know, people know the risks, but they're not really incentivized to do much about them because they're not picking up the tab for them. So that's not speaking to this issue particularly. But are you seeing any particular drivers to do this or even barriers to this? People taking for this evidence and doing something useful with it.
speaker-0: I'll and be as positive as possible when I answer this question. am seeing lots of national level, Scottish level, UK government level, international, you go across to Europe, organisations that are all trying to get to grips with these sorts of challenges. The recognition that we need to be thinking about more about things in the round, hazards in how they interact with each other. all the effects that those hazards can have from a cascading perspective. There's a strong scientific community pushing that agenda forward, but it's also seeing that from the government and the leadership perspective. Of course, the delivery of that is probably really, of course, where the challenge lies. So it's one thing for lots of organizations to be moving forward in this. It's another thing to actually then really implement. I often ask myself this question, what's my role in this? I'm just one academic, a researcher, and I work with and hopefully do some okay work. I see my job in there in how to manage these types of events as kind of flying the flag as to why, why we should care about this, why we should be thinking about our hazards and our risks in this way. Because we are obviously in a time where we are seeing these types of events frequently, more severely, and that's not going to change. I think slowly and surely we'll see a movement more towards this. Certainly in the last 10, 15 years I've seen those terms of compound, cascade, multi-hazard become quite commonplace. I've seen the Met Office now in the last couple of years starting to use this is a multi-hazard event. And I'm secretly quite pleased that it's risen to that level of the agenda where it becomes a bit more commonplace. Still haven't heard climate stacking by the way.
speaker-2: No, you soon will Chris, it'll be on billboards everywhere. Just in terms of where you're seeing this being managed well, is there a secret source that you're kind of... you're seeing, you mentioned Australia, you've mentioned Europe, less so the UK. It might be something you're like, leave it with me, I'll come back to you on this. is there something, I'm thinking breaking out of these of sectoral or disciplinary silos, this kind of connectivity from local right through to national, international, that is kind of joined up thinking spatially. There's so many things I would guess that you would need to have a much more joined up, forward thinking. proactive way of managing these multi-hazards, but is there anything that occurs to you there?
speaker-0: give you two sources for hope. One is we're part of Forum, which is the Climate Ready Infrastructure Scotland Forum, CRiS Forum, not named after me, which is the coming together of the vast majority of Scottish infrastructure owner-operators. So again, it's in the critical infrastructure space. So from the very large operators, network rail, Scottish water, Scottish power. through to some of the smaller regional networks and infrastructure owners. These groups have come together, there's a few universities themselves and a couple other universities that are involved in this, come together very from the bottom up, from the ground up to actually understand quite singly where are the shared risks and responsibilities, recognizing that they all tend to cause operating silos because they're mandated to or they're required to for their business models. Now that forum coming together hasn't been dictated from the Scottish government involved, but it's come from the other way. And that is showing such promise of bringing people together in an open sharing forum to then come together to say, where are our shared risks and what can we do about it? Which moves from the understanding to the management kind of space. Now Scotland is just the right size, right? It's big enough to make a difference. is small enough to make those sort of things manageable. I recognize you can't do that everywhere, but it is a really good example of if you get the right groups of people, the right people in fact, in a room, you can actually make a real difference. But I recognize, of course, that's one slant. That's the critical infrastructure. You would need to repeat that or expand that at the individual level, the household level, the government level. hopefully there's a... by definitions about interconnections, there's a space there. The second example is something that's a bit more abstract, and maybe you've been reading this as well, but I've been reading David Schochman's book, The Response. If you haven't read it, I would urge you and anyone that's reading this to go and read that book, because it accounts, it gives a ⁓ brilliant ⁓ explanation and set of examples. of exactly the sorts of events that we're talking about. It mentions the 2022 heat and fire. It looks at extreme weather and how it's impacting us and how people have experienced it. And of course, it's talking about how we will experience this, of course, in the future. Now in there, there's some brilliant science, but it's written, of course, more from the perspective of its real people. And I'm very envious of that book because it does a 10 times better job than I would ever do about communicating the sort of work that I and many, many others do. I would put it in the category of vital reading because if you really want to know about what climate is, what kind of risks and hazards are and how we are and will experience them in the future, it's one of the best resources and best books that I've come across recently. there's hope in that.
speaker-2: for the hop tip.
speaker-1: There's two hope sources in there. So yeah, thank you. I mean, to be fair, think that maybe I should leave the university and start a spin out company for hope source, because I think we could all do a good dose of that right now. But it sounds like, I mean, I was going to ask, I mean, to me, that's a perfect point to end that discussion. But perhaps just one more, Chris, if you can possibly bear it any longer, is thinking about that kind of what we then do with this at the local level. ⁓ Because I'm aware, for example, I mean, I think the answer you just gave around that equipping yourself with knowledge, whether that's through reading books or listening to podcasts like this, so becoming increasingly aware of this as a challenge ⁓ and how it might impact you. I'm also aware that, for example, community councils are maybe having to tackle things like community climate vulnerability assessments now that are... You know, they are about evaluating extreme weather and climate shifts in a very specific area. So there are things happening at the local level. But if we try and keep that hope source element, dollop them both on our plate and add a bit more, if our listeners are finding some of this maybe a bit worrying because it is, maybe a bit daunting because it is, or perhaps feeling a little bit like no one's really. doing what they need to be doing and that kind of shared risk that you mentioned, that shared risk cuts across all of society, you know, as you loop right back around to one of our very first questions. What can our listeners do to engage more on this?
speaker-0: A very good question, a very difficult one to answer in some ways because going back to the we're all responsible, we all own the risk of thinking. think there are some, this is new, but there are some things that we can all do which is we can, if we have the opportunity and the resource to is we can better equip our homes to deal with high temperatures, likelihood of flooding, can. maintain our building so when we do have extreme rainfall, the water drains better or quicker. We can retain if we have a garden and again it all comes back to money and resource I recognize but if we have a garden you can hold a bit more water in your garden rather than it all going straight into the open sewers. These are all such small things but if we're all incentivized to do that we can all make a slight difference. removing a lot of our impermeable surfaces. Some of our gardens are paved over for car parking. I know these are all real world for a reason, but we could all make those small bits and pieces. But perhaps then how does that connect to the bigger picture stuff? Again, trying to be a little bit more, I don't know, positive, I suppose, is that I know that there are so many activities out there that are trying to... work on this challenge? How do we forecast better? How do we predict these events? How do we deal with them when they arrive? These are known challenges and people are looking at it. I think the challenge of course is making those connections, making it real for people and feeling that people can make a difference and have an element of ownership. I think that's a healthy thing rather than being a hindrance or something negative. It doesn't answer your question fully, but I think that there are elements in there that we can do and bit of hope.
speaker-2: Thank you, Chris. Well, what tour de force and I'm hoping listeners enjoy that half as much as I did because that was really, really great. So you're welcome back. You won't have to wait another 115 episodes to get the next invitation, Chris, because I'm sure after this summer, there'll be plenty more for us to discuss maybe in the rear view mirror.
speaker-1: I just want to kind of just smash apart our diaries right now. I mean, we're all three of us in different rooms, but we are kind of within the same vicinity. So I just want to be like, should we just go meet in a coffee shop across the way and just carry on? But honestly, Chris, we've been desperate to talk to you for a long time. And I know that our listeners would be really fascinated by what we've been discussing with you. ⁓ So thanks so much for giving up your time and talking to us about such a pressing topic. It seems unpleasantly timely. given what's coming down the road. But at the same time, I'm actually feeling a lot more reassured that we have a bit more kind of readiness under our belt than maybe I initially thought when setting out for this conversation. I feel a bit like I've had a good dose of hot sauce, hot tape.
speaker-2: Some hope sauce. Good. Brilliant. Well, thanks again, Chris.
speaker-0: Thanks very much, thanks to both of for having me on.
speaker-1: Well, that was a bit of a tour de force, you know, to use your words, just to really get to grips with that topic. But I feel like we might have just opened a bit of a can of worms. This is great because I really enjoyed that. And I think it'd be great to really unpack some of those things a bit more. Thanks so much for joining us for this episode of Local Zero. I really hope you enjoyed the conversation as much as we did. If you did, then please do share it with a friend, a colleague, or anyone that you think might find it interesting. You can just use the share button right now to send them a link to the episode.
speaker-2: Punch. And if you're listening on YouTube, Spotify or another podcast platform, we'd love to hear what you think. Leave a comment and join the conversation. And if you haven't already, please consider leaving us a review. It really helps more people discover Local Zero.
speaker-1: we are always looking for ideas and perspectives for future episodes. So if there's a topic that you'd really like us to cover, do get in touch by email at localzeropod.gmail.com or connect with us on LinkedIn by searching Local Zero Podcast. See you next time.
speaker-2: for listening and we'll see you next time.