116: What happens when multiple climate change hazards collide?
As our climate changes, extreme weather events are becoming more frequent and severe. But what happens when multiple climate hazards occur at the same time—or in quick succession?
In this episode, Jen Roberts and Matt Hannon explore the concept of climate hazard stacking and what it means for climate resilience. How common are these overlapping risks already, and how might they change in a future shaped by more extreme weather? What challenges do they create for communities, infrastructure and decision-makers—and how should adaptation strategies respond?
To unpack these questions, they are joined by Professor Chris White, Professor in Climate Extremes and Resilience at the University of Strathclyde and an expert on multi-hazard risks across systems and society. Chris explains why understanding climate hazards in combination, rather than in isolation, is essential for building resilient communities and preparing for a changing climate.
Links:
- UNICEF’s Children's Climate Risk Report (2026):
- Climate Change Committee report (May 2026) A Well-Adapted UK - The Fourth Independent Assessment of UK Climate Risk
- Book recommendation: The Response by David Shukman “A Story of Fire and Flood in Britain’s New World of Extremes”
Transcript
Chris White: 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.
Chris White: I think that's a healthy thing rather than being a hindrance or something negative.
Jen Roberts: Hello and welcome to Local Zero, the Strathclyde Institute for Sustainable Communities podcast. I'm Jen Roberts.
Matt Hannon: And. I'm Matt Hannon. And today we'll be discussing climate hazards.
Jen Roberts: 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?
Matt Hannon: 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?
Jen Roberts
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 systems and society. Long time listeners will know. We've been super keen to have Chris on the podcast for a really quite some time, and so we're delighted that the stars have finally aligned.
Matt Hannon
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.
Jen Roberts
And of course, wherever you are listening, don't forget to subscribe so you never miss an episode. We're also on YouTube now, so be sure to find us and follow us there as well.
Matt Hannon
We've been wanting to do this episode for quite a while about multiple climate hazards, hazards, 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.
Matt Hannon
And we're saying this right as and feel like we're saying this all the time. But this coming week we're expecting record breaking heat again. London forecast 40 degree heat in the next couple of days. You're just back from Barcelona. Was it even that hot there?
Jen Roberts
No, it was lovely. But do 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?
Jen Roberts
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. Everybody can't cope.
Jen Roberts
It's too hot. We all proclaim, yeah, in Barcelona. 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.
Matt Hannon
And whether you can write, whether you can prepare for 40 degree heat in in a country, in a built environment, you know, a populist that really isn't familiar with these heat extremes and as I say, doesn't have the infrastructure, the technology, even just the cultural practices and knowhow of how to deal with this, even just like what we dress and where we work.
Matt Hannon
Yeah, but this, this comes this, this record breaking heat this coming week hasn't happened as we 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 heels of a report from Unicef, which spoke to how half of the world's children are exposed to at least three climate hazards.
Matt Hannon
Now, what kind of hazards are we talking about? These are heatwaves, storms, floods, droughts, you name it. You know, it's it's it's sand and dust storms. Half 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.
Matt Hannon
Well, experience more than six of these hazards. Six they they experienced the whole lot. Yeah. It's not an insignificant number of people.
Jen Roberts
Yes. No. And it is worth remembering and maybe reminding people that young people are vulnerable category. So we're talking about heatwaves, those particularly vulnerable in heat waves are the young and the elderly. So it's not that this is this isn't you know, it's not okay anyway, but it's extra not okay when we're talking about the extremely vulnerable.
Jen Roberts
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 I think it is also worth, you know, when we both were talking about that report when it first came out, the fact that actually it's, you know, it's almost every child, including those from high income countries, is exposed to at least one hazard.
Jen Roberts
So this is affecting everybody and everyone is at risk. And I think that's important. It's important to let that settle.
Matt Hannon
And I think it's worth unpacking why we're talking about multi hazards now. So if I maybe let's just do this sort of very academic thing. Let's list the hazards. Right. So so we know what we're talking about here said 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.
Matt Hannon
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.
Matt Hannon
So, Jen, it was your inspiration, I think, speaking to Chris 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 these, these hazards amplifying one another.
Jen Roberts
Yeah. Well that's all we're going to get a chance to talk about that today. And I know it's been sort of circling around. We've discussed before about climate adaptation on the pod. And we've discussed these, these different types of climate hazards or climate risks and some of the terminology I think we're going to be able to get into with Chris today, because I think he'll keep us right as well.
Jen Roberts
We're not the experts, he is. 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 a how you define these sorts of hazards and how localised they can be. So we've had so many questions ourselves.
Jen Roberts
I know that we've talked about it, you know, when recording and not recording. And just to understand this a little bit more and to understand how how they're encapsulated, I mean, I don't I don't know how much we're going to get into with Chris today, but also how well these events series are understood, how well they're catered for into how prepared.
Matt Hannon
How well they're communicated, how do you communicate these hazards. And I just said, we've got a red, 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, it could knock out power station, you know, or you might disable the East or West Coast Main Line in terms of rail, or your local hospitals are unable to function because people can't get to work.
Matt Hannon
So that's, that's, that's 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, and I said this before the recording, I think people can just about bend their head around a single hazard. And what that might do, I still don't think that means they could be prepared.
Matt Hannon
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. And I think until people recognise that, I can kind of, I don't know, conceptualise that, how can we start to act against the true costs of climate change?
Jen Roberts
And I think also to consider with whom is the responsibility to act? Yeah. And there will never be one singular person. But, you know, it comes to things like the West Coast Main Line not operating. It's very clear that's Network Rail and the West Coast Main Line 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.
Matt Hannon
And it comes back to this notion of resilience. You know, we've done episodes on infrastructure before. I think what one thing we haven't talked a lot about, an hour colleague Ian Cairns, as part of the Strathclyde Institute for Sustainable Communities, is writing a piece at the moment about what maketh a sustainable community. What keeps coming back is that either one of the ingredients or actually one of the kind of characteristics or outcomes of that is about a more resilient community, a bit of a kind of a contested term in some senses.
Matt Hannon
But ultimately, when things start falling apart around you, and those organisations are authorities who are normally responsible for keeping whatever it is health care 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 neighbour and vice versa?
Matt Hannon
At what point do you need to have these 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.
Jen Roberts
You may not. Yeah. You don't see so often in suburbia, perhaps you definitely exist. Yeah. You're right. And I think the other thing that's really interesting to explore here with that definition of sustainable communities, is that that's typically requires living within planetary boundaries and safe planetary limits. And we understand now that we have overshot various planetary boundaries in various planetary limits.
Jen Roberts
So there is perhaps I mean, we're putting a maybe a bit too much on our conversation with Chris today. I suspect this will cascade.
Matt Hannon
He'll have all the answers. Don't worry.
Jen Roberts
Yeah. And so I think it's again in future episodes around, is it even possible to have a climate resilient, sustainable community? Yeah. Given the context of operating within planetary boundaries and how many of those have been overshot or broken down?
Matt Hannon
Yeah, yeah, because it's almost like that, that those natural capital stocks in the ecosystem services they provide are your way of riding out the bumps in the road. But if you've actually if the climate has ravaged, 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 I don't want people to be listening to this.
Matt Hannon
I'll just turn this off. This sounds extremely depressing. And, you know, I think there is a point, just a pure pragmatist standpoint for me is that we need to be able to connect these because we need to understand what. 5, 10, 15, 20 years looks like in order to start planning for this stuff. So, you know, unless you're going to shuffle off this mortal coil pretty quickly, you should even just from an individual standpoint, care about this.
Matt Hannon
But for for friends, loved ones, it is about how we start making it's preparedness and it's about policy decisions. It's about from the very smallest community or individual all the way through to Westminster, Whitehall, Holyrood, Brussels. These decisions matter and I honestly think we're still looking at stuff through the lens of individual singular hazards.
Jen Roberts
But this is what we'll find this.
Matt Hannon
Out exactly his perspective. Hopefully we'll be able to connect the dots for.
Jen Roberts
Me, connect the dots. And also with all of this, you know, climate is incredibly uncertain and climate projections is 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. What do the we've got numbers and narrative equals change right.
Jen Roberts
So first of all what do we know. And then that narrative of what okay what do we do with this. Yeah I agree that this is for listeners who are thinking this might be also extremely academic and very jargon based. We're going to do our best to bust the jargon and do our best to to also really unravel not just what's the current knowledge and state of the art, but also what's next for this, this area of of work and policy and, and then bringing it back down to our everyday lives.
Jen Roberts
Everything we're about. 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?
Matt Hannon
Yeah. And the bigger picture 100%. Yeah, right.
Jen Roberts
I think we might need like three hours with Chris. So should we bring him in?
Matt Hannon
Yeah. He’s cleared the diary.
Jen Roberts
Let’s get started.
Chris White:
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.
Jen Roberts
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.
Chris White:
We are indeed. It's a bit of an inside job today.
Jen Roberts
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 all align.
Jen Roberts
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, because even then when you introduced yourself, you're talking about hazards, you're talking about risks, you're talking and infrastructure. So I think there's a few things we'll be getting dug into today that I've not really had a chance to ask you about before.
Jen Roberts
So 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.
Chris White:
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 so this is a this is a perfect opportunity. All right. I'll try and unpack it a little bit to to start with I want to start, if I could with what a hazard I know that's, that's, that's that's really really straightforward.
Chris White:
But a hazard is really the centrepiece of what the sort of work that I do, a hazard in this context and the 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 word climate and hazard together, that's really what that means.
Chris White:
It just means an artefact of extreme weather. Probably that will be an 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. A risk of causes, a very difficult thing to quantify. We all do it all the time. We all make our own assumptions and risk assessments.
Chris White:
Do I take an umbrella out on the basis of what the weather forecast says today? We're doing our own level of trying to understand risk, but from a science perspective, risk has a quite a specific definition. And risk is actually a three way equation, three ways for discussion really that goes between a hazard. So that as I said a moment ago, that's the flood the the the drought, the storm.
Chris White:
But there's two other components to that, which is in a very formal way is exposure and vulnerability. And there it’s important that you have to look when you think 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.
Chris White:
It could also, of course, be people. And often when we're dealing with climate risk, which 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 the most that's 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.
Chris White:
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 the changing climate, and then how can it affect us, our way of life, our transport, our networks?
Chris White:
And what can we do to to be more prepared and more resilient to, to those types of phenomena?
Jen Roberts
Amazing. Yeah, that's super helpful. Thank you. I think then what 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.
Matt Hannon
TM. Copyright. That's you heard it here first. It's an inside scoop.
Chris White:
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.
Matt Hannon
You can come on as a second or third author, Chris. Absolutely. Fine.
Jen Roberts
Honestly, I to me it conceptually I think makes sense of what it is that you work on. But 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, what is a compounding or cascading?
Jen Roberts
Was it would it be hazards, compounding hazards? What is it exactly. Just expand on what you do.
Chris White:
Okay? All right. So yeah we're getting into into the territory of lots of definitions, often meaning again the same sort of thing. And and it gets a bit complicated. I'll try and break it down as really simple, as easy as possible. So we tend to think of things quite singularly and often in silos. So take for example a flood.
Chris White:
Right. We know that a flood we can be caused by a 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. Could be flash flooding, all sorts of types of flooding. But ultimately it's they all sit in the realm of hydrology. Now, hydrology is a is one subset of a broader climate piece or climate discipline.
Chris White:
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 the storm actually is a really good example of that.
Chris White:
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 of another, coastal nation perhaps, or surface water flooding. So the space that I tend to work and I wouldn'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 modelling and the predictions of the climate hazard and risk space, which is recognising that many things connect with other things.
Chris White:
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 now, a drought we will probably tend to think of as from how it affects us.
Chris White:
You know, 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 perhaps low levels of rainfall over a period of time. The soil, the water in the soil, soil moisture needs to be somewhat depleted, past river flows low and of course, increasing demands.
Chris White:
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 recognising 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.
Chris White:
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. Yeah. So perhaps if I start actually with the second one of those two, the triggering one. We've seen globally and happens in, in so many places, we have really extreme rainfall will then increase the likelihood of landslides and landslides of course can be deadly in the parts of the world are very susceptible to landslides, two fundamentally different mechanisms.
Chris White:
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 got to be really wet. And of course we have a steep slope for a landslide to occur that wouldn't occur without the rainfall part of it, but they're often again thought about in different ways. One one’s in that geological space, one’s in the hydrological meteorological space.
Chris White:
So the 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 ready 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.
Chris White:
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 have to think back to 2022, where we had the really extreme temperatures, in particular in the southeast and around London, and we saw for the first time 40 degrees in the UK, which for someone like myself, who has been studying climate for longer now than I want to recognise, the idea of having 40 degrees in the UK felt like middle of the century, end of the century type stuff.
Chris White:
And 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, you know, people that are vulnerable to to temperatures.
Chris White:
But some of the most significant impacts that happened during that event, of course, were the temperature, but is also the accompanying wildfires that came with them. And it was that part, that interaction between not just one hazard, but and now a multiple set of hazards that really, of course, caused certainly some of the most visceral visual impacts that we saw from that event.
Chris White:
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. Yeah. If you want a powerful message of what climate change is, is and what it's bringing, that's it.
Matt Hannon
I've actually got goosebumps from what you're referring to, because I remember seeing- It was one of those moments. There's 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 bit discombobulated because I seeing this and there were these houses that had just been raised, these cars that were on flames.
Matt Hannon
It was an aerial shot, and I just assumed I was looking at California until I realised these were kind of, you know, post-war 1950s kind of semi houses, a little white plastic furniture in the guard, Vauxhall Corsa on the driveway in flames. It's like, this isn't California. This is this is the south east of England. And you're quite right.
Matt Hannon
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 I want to 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, it might be an insurance company, it might be somebody putting on a major event like Glastonbury or Wimbledon or whatever it is.
Matt Hannon
We need to get on top of this. So we are prepared for all eventualities. So, so two questions in that is this is this a kind of a new or more popular phenomenon. And to who's coming to you with these questions.
Chris White:
So two- 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 she I've got to answer my own question. No they're not that we're very good at creating terms new terms new scientific terms.
Chris White:
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. So the over the last, I would say 20 years or so, there's been a- certainly the last 15- a movement from just thinking about things, generally speaking, in that single way through to, you know, we need to be thinking about about these in a more real world system kind of kind of way.
Chris White:
And events like the 2022 heatwave 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 was a busiest day since World War two.
Chris White:
Wow, 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, this podcast. Today is the first day of amber and tomorrow will be red weather warning for London for again, very similar temperatures that were forecast for 2022.
Chris White:
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, in the calendar year from the 22 year, we're in June, not July.
Matt Hannon
Which which kind of organisations might be reaching out to you or colleagues now or what I'm trying to get at is who, who? And Jen made this point in the 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.
Matt Hannon
But who 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.
Jen Roberts
Would be everybody.
Matt Hannon
Or everybody.
Chris White:
Yeah. I was about to say what Jen just said, which is everybody. Well, perhaps I can find a middle ground in there, which is it should be everybody. And I like, explain what I mean. So I'm an engineer. Jen and I are in a civil engineering department. I did some engineer as a background, so. So a lot of my work is actually about translating this sort of work or the sort of science, as you often through an engineering context.
Chris White:
So I use the words of critical infrastructure. So at the beginning critical infrastructure to me is our built environment, the power networks, transport, roads, water supply. It's I tend to think about the things that we rely on and that connect us actually. So that's what we want to mean by critical infrastructure. So therefore it means a lot of the people that I tend to work with or I think use the words who comes calling on me for advice or research is probably typically critical infrastructure owners, but that's more of a product or an artefact of who I am and where I work.
Chris White:
The reason I said everybody, everyone's responsible. If you expand that to us, us now as people, everyone as people, communities will live on streets and roads and in houses, in towns and cities and villages. Yes, we all rely on critical infrastructure. And there's a good way of analysing this from a large scale perspective. But the everybody bit comes into, I think increasingly we all have a responsibility or increasing recognition that we have a responsibility to prepare ourselves for these types of events.
Chris White:
Now, that puts a lot of emphasis and onus on us as to be aware, and I'd like to think that some of the work, a little bit of the work that I do, helps to raise awareness of the challenges, but also hopefully trying to provide at least an idea of what some of the solutions are. And I can reference Australia as a really good example of this.
Chris White:
So I have an Australian passport so I can put my Australian hat on now at this point and say culturally, and this is 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 than you can possibly think of.
Chris White:
And so it's a it's a tough country. And so to survive, I think as a society, as a culture, it's ingrained that self-reliance and that preparedness in the culture. So everyone, or at least certainly people I knew, everyone had a bushfire plan. Everyone knew what to do with the 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.
Chris White:
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 what I need to do this, or someone's going to clean up and mop up afterwards, or is going to build that road better, or move that train line to a different place because of it.
Chris White:
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 native. It's not going away anytime soon.
Jen Roberts
Yeah. I was thinking actually in this, this run of, 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 it had some really specific, actionable nuggets of information around how to keep your house or your flat or your office cool.
Jen Roberts
And I was I was sharing it on not to lecture or to promote the pod, but actually just to be the guys. You might be interested in this because of the conversation that you've been having. And I was thinking there because there is this cultural, this expectation that this kind of lack of awareness of proactive action, actually taking responsibility, but also being proactive in reducing the risk of something.
Jen Roberts
And this leads me back around to something I'm really interested about. You touched on earlier around the wildfires that came with that, the 2022 heatwave and that's, you know, are we talking now about natural hazards? Often when we think about flooding and fight, we think we use the word natural hazards. My background is in earth science, in environmental science.
Jen Roberts
And are we talking about natural hazards? We always think about earthquakes, volcanoes and so on. I think there's something really interesting here. When we're talking about climate change, the probabilities have become a 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.
00:35:44:10 - 00:36:06:14
Jen Roberts
But if we link back to that, 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 man made or is it a bit in between? And does maybe our classification of of hazards need to need to change a bit?
Chris White:
Wrapped up in there was a was a really good question.
Jen Roberts
In not known for my conciseness, am I?. Sorry.
Chris White:
I suppose by definition, you know floods are going to occur. Heatwaves are going to occur no matter what we do or don't do. And so that's hence the term natural and natural hazards is a term that's being used and being used for, for quite, quite a long time.
Chris White:
The climate part to that, the climate change part then changes the likelihood of something happening or perhaps 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.
Chris White:
Does that then change it from a natural to a non-natural hazard? No, not really, because it's still a flood or a storm. It just has changed the likelihood. So then to go back to the bit I had at the beginning, this 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 that the dynamic.
Chris White:
You might have the same amount of people or exposure, but now suddenly we've got a heightened risk and a likelihood.
Matt Hannon
Chris, we've talked about multi hazards new seminal term hazard stacking. And but you also I think made reference to hazard cascading. And I wondered whether we're talking about something different here.
Chris White:
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 word 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.
Chris White:
But the cascade part, as she 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 a bit simpler. So take the London Heathrow power outage, that happened in 2025, not driven by a climate event.
Chris White:
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.
Chris White:
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 are trying to get to the airport, the transport networks that are all relying on that, that airport operating, that type of event was a significant event for Heathrow and of course the surrounding area and people travelling.
Chris White:
That's a good example, let's say, of a cascade, a cascade of impact, something that affects something else. And 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.
Chris White:
That's the direct part. So the cascade risk or cascading risk or impacts moves, perhaps, 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 on everything working and just on time type of deliveries.
Chris White:
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. And in there there's been work being 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 central, the centrepiece.
Chris White:
If you lose power, the the likelihood of impacts going from, let's say, local scale to 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, losing the ability to have power. And then think about all the knock on effects of that.
Chris White:
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 they impacts us, it's even more complicated when you're starting to bring in the cascade and the interdependencies between our, our systems and our networks.
Jen Roberts
How well- So, I mean, yeah, I can say- I mean, my head's already starting to hurt a little bit, but how 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, you know, the science is pretty well known?
Jen Roberts
Maybe the models handle this very well? maybe they don't? Maybe that's what you need to work on? And where is the kind 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?
Chris White:
I hate to answer this, but it's both of those two. Actually, I think I think people are trying to tackle that challenge from both perspectives. So we can go back to the the last couple of UK climate risk assessments, the Climate Change Committee, every 3 to 4 years to 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 risk sit.
Chris White:
And it 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 highlighted, those risks, but we haven't really got to grips with it yet. And so it's been tackled from two ways, right? One is, of course, that recognition and the potential how do we manage them.
Chris White:
But to get to that point actually and this is perhaps where it becomes more of a semi research type of activities, how do we evidence them? How do we know what these interconnections are? Even even the simple thing of what's the evidence of them. So I'm a academic so and I love data and analysing 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, for a power system or a telecommunication system.
Chris White:
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 connected that piece of infrastructure, and is it reliant on this? They're not built in that way. I mean, half of our infrastructure is built in the Victorian time. So yeah, they're not they're not wired in that way.
Chris White:
So a big gap, a big area of open research. And this is probably one of 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. What where are the critical points in the system where the weak bits?
Chris White:
This comes back to that risk exposure of, you know, where are the weak bits in there, where are the most susceptible. So when something like a heat wave and pass, the potential for a fire occurs where where the likely impact is 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?
Chris White:
To come back to the 2022 example here, we saw what 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.
Matt Hannon
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.
Matt Hannon
You know, people know the risks, but they're not really incentivised to do much about them because they're not picking up the tab for them. So that's 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?
Chris White:
I try to be as positive as possible and answer this, this question.
Chris White:
I 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 the how they interact with each other, all the effects that that those hazards can have.
Chris White:
From a cascading perspective, there is a strong scientific community pushing that agenda forward. But I'm 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 organisations to be moving forward in this. It's another thing to actually then really implement.
Chris White:
And, and I often ask myself this question, what's my role in this? I'm just one academic research and I work 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 more frequently, more severely, and that's not going to change.
Chris White:
So I think slowly and slowly and surely will see a movement more towards this. Certainly in the last 10 or 15 years I've seen those terms of compound cascade, multi has 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 secretly quite pleased that that it's risen to that level of the agenda where it becomes a bit more, a bit more commonplace.
Chris White:
Still haven't heard climate stacking by the way, but.
Matt Hannon
Know you soon will Chris. It will be billboards everywhere. Just in terms of where you're seeing this being managed well, is there a secret sauce that you're kind of that you're seeing? You mentioned Australia. You've mentioned Europe, less so the UK, it might be something you like. Leave it with me. I'll come back to you on this. But is there something I'm thinking breaking out these sort of sectorial or disciplinary silos, this kind of connectivity from local right through to national international, this kind of joined up thinking spatially.
Matt Hannon
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.
Chris White:
I'll give you two sources.
Chris White:
For for for hope. One is selfishly but it's a local thing that we're doing here in Scotland which 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 as a few universities.
Chris White:
Myself 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 singularly where the shared risks and responsibilities, recognising that they all tend to cause operate in silos because they're mandated to or they're required to for their business models. Now that forum coming together so it's not hasn't been dictated from Scottish Government.
Chris White:
It's 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 to the management kind of space? Now Scotland is just the right size, right?
Chris White:
It's it's big enough to make a difference. It's small enough to make those sort of things manageable. I recognise 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 recognise, of course, that's one slant, that's the critical infrastructure.
Chris White:
You would need to repeat that or expand that at the individual level, the household level, the the government level. But hopefully there's a cause because by definition is about interconnections. There's a, there's a there's a space there. The second example, it's a bit more abstract, but and maybe you've been reading this as well, but I've been reading David Shukman's book, The Response.
Chris White:
And 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.
Chris White:
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 a very envious of that book, because it does ten times better job than I would ever do about communicating the.
Chris White:
Sort of work that.
Chris White:
I and many, many others others do. But it's I would put it in the category of vital reading, because if you really want to know about what climate is, what climate 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.
Chris White:
So there’s hope. There's hope in that.
Matt Hannon
Thanks for the hot tip.
Jen Roberts
There's two hope sauces in there. So yeah. Thank you. I mean, to be fair, I think that maybe I should leave the university and start a spin out company for Hope Sauce, because I think we could all do with 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.
Jen Roberts
But perhaps just one more, Chris, if you can, 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.
Jen Roberts
So becoming a increasingly aware of this as a 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 a 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 we try and keep that hope source element, dollop them both on our plate and add a bit more.
Jen Roberts
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 another very first questions.
Jen Roberts
And what can I listeners do to engage more on this?
Chris White:
A very.
Chris White:
Very good question. A very, very difficult one to answer in some ways because you going back to the we're all responsible. We all own the risk kind of thinking. I think I think there are some 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.
Chris White:
We can maintain our buildings. So when we do have extreme rainfall, you know 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 recognise. 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.
Chris White:
These are all such small things. But if if we're all incentivised to 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, you know for a reason, but we could all make those those small bits and pieces.
Chris White:
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 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?
Chris White:
These are known challenges and people are looking at it. I think the challenge, of course, is making that, 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 but I think that there are elements in there of that we can do and a bit of hope.
Matt Hannon
Yeah. Thank you Chris. Well that- What a 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. Thank you.
Jen Roberts
You 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 for a long time, and I know that our listeners would be really fascinated by what we've been discussing with you.
Jen Roberts
So thanks so much for giving up your time and talking to us about such a pressing topic. It seems unpleasantly timely given what 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.
Jen Roberts
So I feel I feel a bit like I've had a good dose of of hot sauce, hot hope sauce.
Matt Hannon
Hope sauce, yeah.
Chris White:
Good.
Matt Hannon
Brilliant. Well thanks again, Chris.
Chris White:
Thanks very much. Thanks to both of you for having me on.
Jen Roberts
Well, that was a bit of a tour de force, as 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, which is great, because I really enjoyed that, and I think it'd be great to really unpack some of those things a bit more.
Matt Hannon
100%.
Jen Roberts
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 a share button right now to send them a link to the episode.
Matt Hannon
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 as a review. It really helps more people discover Local Zero.
Jen Roberts
And 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.
Matt Hannon
Thanks for listening and we'll see you next time.
Jen Roberts
See you next time.