From extreme to extreme: The future of climate in Nova Scotia

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Jordan We often focus on policy when we discuss the climate crisis, the big levers of government that move or often don’t move and determine just how seriously we are prepared to take our current situation. And we talk a lot about records too, and the headlines they make when something extreme happens. Like in Nova Scotia a couple of months ago, Described as a rolling freight train tonight, these out of control wildfires in Nova Scotia have torched. Tens of thousands of acres triggered mass evacuations and destroyed hundreds of homes, Or in Nova Scotia a couple of weeks ago. This is not a river, but a road in Halifax. It’s a scene of destruction familiar across Nova Scotia After torrential downpours triggered historic flooding, leaving much of the province underwater.

And then come hurricane season, we might well be talking about Nova Scotia again as warmer waters let storms keep their strength longer as they head north. When we focus on these extreme events, though, what we often don’t ask is how they’re connected, how one extreme can beget another and another until it’s not so extreme anymore. And it’s just the new normal, so much. Like two years ago when a devastating fire season followed by an atmospheric river had us wondering what the future held for British Columbia, it’s time to ask what the next 10 years will look like in Atlantic Canada and in Nova Scotia in particular, and what the people and governments there need to do to be ready for it. I’m Jordan Heath-Rawlings. This is the big story. Dr. Kent Moore is a professor of atmospheric physics at the University of Toronto. We are speaking to him right now while he is in Nova Scotia.

Hello, Kent.

Kent Moore Good morning.

Jordan I’m gonna ask you this because, uh, it’s something that I ask everybody we talk to about climate these days. As somebody who knows how these kind of weather events and weather systems can compound on one another, how are you feeling these days about, you know, what you’re seeing all over the place?

Kent Moore Well, you know, we’ve known that as we continue to increase the concentration of greenhouse gases in the atmosphere, we’re going to see more extreme weather. I think it’s probably becoming a bit more extreme, uh, quicker than I thought. I thought we might be in this situation another 10 years or so. But it seems that the climate system is reacting much more quickly than at least I thought, to the changing concentrations of greenhouse gases.

Jordan How does that bode since you were expecting this in 10 years, how does that bode for 10 years from now?

Kent Moore Well, that’s, I think, the concern that a lot of us have. I mean, you know, the Paris accord made a big deal about keeping the increases in the global average surface temperature below one and a half degrees above pre-industrial level. We’re at about 1.1 degrees now. And so this, this kind of quality or quantity of extreme weather, I think is something which I say we would’ve expected probably when we got to 1.5. We’re seeing it a bit lower level.

Jordan What we wanted to talk to you about today though, is particularly what’s been going on in Nova Scotia, but also Atlantic Canada this summer a couple of years ago when, uh, as I’m sure you recall, uh, Lytton, B.C. was destroyed and there were horrific wildfires as well as an atmospheric river out in British Columbia. We were saying that BC was on the front lines of the climate crisis. If I said that this year, that was Nova Scotia and Atlantic Canada. Is that fair?

Kent Moore I think it’s quite fair to say that, yeah. You know, if you think about over the year, uh, there was a hurricane, you know, last fall, uh, where the wildfires and then now this really extreme weather event, uh, the rainfall event. So yeah, it, it seems that Nova Scotia is sort of feeling it this year. I think the thing we gotta understand is that every region of the world is, has some susceptibility. And so this year, you know, it’s Nova Scotia. Next year it’ll be somewhere else, but on average we’re gonna see more of these sorts of extreme events moving forward. And I expect that Nova Scotia for a bunch of reasons, hopefully we’ll get into, is kind of uniquely poised to be one of the kind of areas that’s quite hard hit by climate change.

Jordan Can you give us a sense of just the scale of the rainfall and the floods we saw a little bit over a week ago? Like how big were they compared to what I guess would be a normal range for a summer storm or, or a wet period?

Kent Moore So on average in the summertime, Nova Scotia, this Halifax gets about a hundred millimetres of rain in a, in a month. Okay. That’s a typical rainfall. The summers tend to be a bit drier in, uh, uh, Nova Scotia, uh, just because most of, most of the weather Nova Scotia comes from these large winter storms that move up the East Coast, the nor’easters or whatever. So rainfalls in the summer tend to be a bit lower. A hundred millimetres would would be an average. And so, um, environment Canada estimated that there were locations that got 300 millimetres of rain in about 10 hours. So that’s three months of rainfall. In less than a day you would talk about the atmospheric river in BC I think, uh, hope BC got about 180 millimetres of rain in that atmospheric river. So this was almost twice as large as the amount of rainfall that that happened. I mean, I was here during that event and it thundered lightning where I was for about 10 hours. It was just insane. I don’t think I ever, that continual level of kind of thunderstorm act activity. And, you know, I come from Toronto, which has a lot of thunderstorms, but that was really off the charts. And, and so I think it really was a, just an amazing event. I think the last time that there was out amount, rainfall was a hurricane back in 1971. So, so it really is a, you know, it is an event which, which may only happen once every 50 years. So it was pretty, it was pretty epic

Jordan While you were there watching it, is there a moment when you’re watching something like that, which obviously you’re, you know, professionally interested in as well, where it goes from like, wow, this is really interesting and this is really cool to I can’t believe we’re seeing this kind of, uh, this kind of rain too. Like, oh boy, this is a little worrisome.

Kent Moore Well, you know, it happened at night, so it wasn’t clear how much, I mean, I could hear the rain falling, but it wasn’t clear how much was falling as often. Sometimes you can get thunder without thunder and lightning without much rainfall. So, so to me, I, unfortunately it happened at, at night. I would’ve loved to have seen it, frankly, just serve as a, like a busman’s holiday kind of thing. But we did check the basement. I went down the middle of the night and checked and checked the basement. There was, there was no flooding in, in the basement. And then really when it sunk in was the next morning, uh, we got up, my son lives in Halifax, and we were driving in to see him and we’re on the end of a very narrow gravel road. And the road had been washed out where we were, and then driving on the main highway into Halifax. For some reason, they hadn’t closed it yet when we were on it. And, and we saw some just amazing, you know, half of the road had been washed away in, in parts. Wow. And now the road’s closed and, and they of course are, uh, repairing it. So I don’t think it really sunk into me until the next morning until I saw the damage on the, on the 103. And then you hear about, you know, the people that were lost you know, the extreme flooding and Bridgewater, there’s still a couple of bridges that are out in Chester. There was a bridge that was out as well. So I don’t think it really sunk into me how much rain actually fell until the next morning when I could start seeing some of the damage. And our lake level we’re on a lake, and the lake was up probably about three feet. Wow. Which was just insane. I mean, I’ve never seen the water go up that, that fast. And so it was kind of after the, after the fact that I just realised how extreme it really was.

Jordan: Did the volume of rainfall have anything to do with the wildfires in the past month?

Kent Moore I don’t think so. So, you know, Nova Scotia went through this kind of whipsaw, if you like. So they had a really, really, it was a really dry spring and a really dry winter in Nova Scotia. So I think like in, I think in April there was only like a half the amount of rainfall that was usual. So the spring was really dry here, and that’s what helped I think, trigger the, uh, wildfires. And then it started to rain and it’s been quite wet in Nova Scotia for, you know, even into, into June as well as in as into July. And so, you know, that’s the kind of flip flop that can happen. We can have dry seasons. We, we, we can have wet seasons. The one thing that climate change is doing is it’s kind of amplifying the extremes. And so, although I think the case hasn’t been made yet, but I would surmise that the drought, uh, in the spring was probably exacerbated by the changing climate. And as well as the extreme rain rainfall event in July was also again amplified by the changing climate.

Jordan I guess we’ve seen a lot of stories this summer about ocean temperatures, especially down towards Florida and the Carolinas. What has the water temperature out on the East Coast been like?

Kent Moore: Well, it’s warm as well. So there’s warm water all up along the eastern seaboard, so off of Nova Scotia, the water may might be upwards of five degrees warmer than it usually is this time of year. And I think that that was one of the things that, uh, contributed to the extreme rain rainfall event, is that when the water is, when the ocean is really warm and the atmosphere’s warm as well, it’s easy to evaporate lots of water outta the ocean. And that of course, water ends up in rainfall. Mm-hmm. . So I think the, the extreme warmth of the ocean temperatures off of Nova Scotia contributed to the extreme rain rainfall event. I don’t know why they’re so warm. I mean, this is one of the challenges in the climate system. It’s quite easy to observe things like, you know, we have satellites that observe sea surface temperatures and things, but understanding why it’s so warm, it takes more time, uh, of, of course the oceans are warming up. So again, we always talk about, you know, global average surface temperatures. That’s the kind of indicator that we talk about climate change. But of course, when the atmosphere warms up, some of the heat goes into the ocean. So the oceans have been warming up, you know, for the last 150 years. And so they’re warmer now than they were back then because the oceans have a huge, uh, what’s called heat capacity. It takes a lot of energy to warm up a kilogram of ocean water. So they don’t tend to rise as rapidly as, as the air does. But the oceans have been warming up. And again, this warmth we see off of East Coast this year is probably partly that long-term warming and partly some, uh, sort of shorter term, uh, climate fluctuation, which is leading to warm water. So it’s a combination of what you call weather. So weather’s kind of the fluctuations you get from day-to-day and climate is sort of the long-term average. So those two things are super imposing. Uh, and that’s what’s giving us the warm water off of Nova Scotia this summer.

Jordan What does that mean for the fall and I mean specifically hurricane season?

Kent Moore That’s a good question. So, you know, the warmth extends way down into the Florida and, and into the Caribbean. And of course, hurricanes are essentially driven by warm sea surface temperatures. That’s why we typically have a peak in our hurricane season in September because it turns out that that’s when the oceans tend to be their warmest, they kind of gain all that heat over the summer and they’re at their warmest point in September. Mm-hmm. . So expect the hurricane season will be more intense than usual. And of course, uh, you know, there’s two main hurricane paths. Either hurricanes get into the Gulf of Mexico, then they kind of come on shore like in Texas or Louisiana. Then they typically die quite, quite quickly as they move over land moving up north. The other track has them come up kind of the east coast of, uh, north America, you know, past Miami, up through the Carolinas. And those are the ones that typically come in impact with Nova Scotia. So it could be a, a more intense hurricane season. The one kind of wild card in this is El Nino. So El Nino is this, again, very large scale climate fluctuation. Every four or five years, the warm water, which is usually in the Western tropical Pacific moves eastwards and the warm water ends up off of, uh, Peru and in that region of South America. And it turns out that when you get an El Nino, there’s kind of, I should back up, but there’s kind of two things that, that you need for a hurricane. You need very warm sea surface temperatures and you also need the atmosphere which just essentially have no, what’s called wind shear with heights. So essentially the winds should be uniform as a function as you move higher up, up in the atmosphere. And why that’s important for a hurricane is hurricanes kind of stands upright. That’s why when you look into the eye of a hurricane, you can see right down to the surface ’cause there are sort of vertical. And if you get lots of wind shear in the atmosphere, that tends to tilt the hurricane as a function of height and that makes them less efficient. So hurricanes want to be standing straight up and, and, and so the El Nino is just starting now, but when you get an El Nino, you tend to get more wind shear in the tropical atmosphere, and that tends to kind of tilt the hurricanes over. So there’s that compounding factor. El Nino really is just starting now. It’ll be most strongest this winter and into next, next year. So I expect the main impacts of El Nino will happen next hurricane season, not this hurricane season, but it’s possible that they might be a bit weaker than usual just because there’s more wind shear in the atmosphere.

Jordan I’m glad you mentioned El Nino because over the course of the past few weeks, especially when we’ve seen some record breaking temperatures, obviously in the US and, and yeah, these more motion temperatures, et cetera, I have seen some people making the argument that, you know, this isn’t actually all due to climate change and it’s not sort of a supercharged this year thing. It’s actually just normal climate change, I guess, if that’s a thing plus El Nino. But you say it’s it’s not quite begun yet.

Kent Moore No, the El Nino, so El Nino is Spanish for the Christ child. And the reason it’s named that is ’cause the warm water usually appears closer to Christmas time off of Peru. So it’s starting to build up now. It hasn’t reached its peak yet. Mm-hmm. And, and, and so I take exception to this idea that we’re seeing El Nino happening now because it really is the water’s not that warm. Again, it’s focused in the tropical Pacific. And so you might say, well, how can warm water in the Tropical Pacific affect us in Canada? And that’s really good question. So there’s local climate changes due to the presence of that warm water. And then there are, there are kind of wider or, or longer aspect changes. And so it turns out that the reason that El Nino impacts weather in Canada is that the jet stream, which is most, which is strongest in the wintertime, it tends to be kind of moved around by the presence of this warm water. It impacts the, the, the location of the, of the jet stream. And so that’s the way that El Nino impacts us is it’s not that warm water directly, it’s this intermediate thing that warm water perturbs flow in the atmosphere that perturbs the gulf, the, uh, jet stream. And that’s the impact. So I expect this winter will be a mild winter in eastern Canada, probably a wetter winter in Western Canada. ’cause that’s typically what El Nino does. And, and so I think it’s too early to see the effects of El Nino now. Uh, we’ll see them mostly in the wintertime. Uh, and it’ll be next, next winter that we see those, those effects. And then they’ll follow through, uh, into next summer as well. Because once this jet, this wind shear and the atmosphere gets set, set up, it tends to persist. And so expect next hurricane season, not this year, but the next year’s one might be a bit weaker than usual just because there’s lots of wind shear in the atmosphere and that tends to weaken the hurricanes.

Jordan I know we can’t predict extreme weather events, and I know whether itself extreme or not, uh, can fluctuate and, and is not like climate. But when you look at, at Nova Scotia and the East Coast, what can we say about the next several years in general that might help people know what to expect? Like we, should we be looking for more a hundred plus millimetre rainfalls? Like what is changing on maybe a macro level?

Kent Moore So that’s a really good question. So again, so climate is all about averages. And one way I like to think about this is, suppose you have a dice. Okay? It’s got six faces on it. You paint three of those faces red, you paint three of them blue, and you roll the dice. Right? And if it’s red, that means you have a warm summer. If it’s blue, it means you have a cold summer. That is sort of the way you can think about climate. On average, we’ll have some warm summers on average, we’ll have some cold summers. What climate change does that changes the nature of the, of the dice. And so maybe now there’s four red and there’s two blue. Hmm. And so when you roll the dice, you’re gonna get on average more hot summers or more rainy summers and less cool summers or dry summers. So that’s the way it kind of works. And, and, and, and so the thing to realise is that we’re not gonna see another 300 millimetre rainfall event probably for a few years. Right. But there’re gonna become more common if the last one was back in 1971, we might see another one, let’s say in 10 or 15 years. Right? Right. So that’s the kind of way it’s gonna go. So on average, our climate’s getting warmer on average, we’re gonna have more of these extreme rainfall events, but we’re still in this nature where it’s maybe, you know, four fi four faces are red and two faces are blue. As time goes on, as you continue to change the climate, more of those faces turn out to be red that say. And so this is an example that that, not with respect to rainfall, but it’s with respect to these extreme temperatures. And so there’s, there’s been a recent analysis by the UK med office that says that the extreme temperatures we’re, we’re, we’re seeing in Europe today, they’ll occur right now once every, let’s say 10 years or 15 years. But by the year 2060, if we continue to emit carbon dioxide the way we’re doing it now, that will become the new normal. Okay? So by 2060, that dice will be all red and we’ll be getting those warm summers and that’ll be the new normal. And of course the extremes will then be on top of that, right? Mm-hmm. . And, and so that’s, I think what our future is. And I think Nova Scotia is a little bit, I think, sensitive for two reasons. First of all, uh, you know, as the ocean warms up, we’re going to see more impacts of that warm ocean. And that generally needs more evaporation, more humidity. I was quite actually surprised leading up to that rainfall event. It was really humid in, uh, Nova Scotia more so than it usually is. And again, that was the impact of that warm water off of Nova Scotia that was allowing lots of evaporation happening. And so we’ll see, I think more humidity events in Nova Scotia, more thunderstorms, thunderstorms aren’t that common in Nova Scotia. And, and that’ll be happen moving forward. And the other I think climate, uh, kicker for Nova Scotia is the hurricanes. As the ocean warms up, again, not local ocean warming, but this is not ocean warming. Farther south, we’ll see more intense hurricanes in Nova Scotia as well. And then as we get warmer water, so hurricanes survive off warm water, and so they generally start to die as they move northwards. ’cause the ocean temperatures get cooler. But as the ocean temperatures warm up, those hurricanes can maintain their strength for longer. And that’ll also I think, lead to, uh, more intense hurricane events in Nova Scotia.

Jordan So let me ask you this finally then, and, and we can, and have done whole episodes and whole series about what politicians have and mostly haven’t done to prevent climate change in the macro. But you’re somebody who owns some property out there, you say your son is in Halifax. What would you do to prepare for what Nova Scotia’s gonna see the next 10, 20 years?

Kent Moore I think we need to harden our infrastructure. So, you know, it’s important to have a, have a generator. So if the power goes down, you know, you have backup power, you know, I’m on a small road and there’s a little bridge, if that bridge washes out, there’s no way out of my area, right? So I think it’s also important to kind of make sure you got alternate ways to get out. That was a big problem, uh, in the wildfire near Halifax, right? Is that there was, uh, they hadn’t planned enough kind of alternate escape routes outta the subdivision. And so people were kind trapped by the fire. So I think we need to harden our, our infrastructure. Uh, you know, the fact that parts of the main road to Halifax were washed out shows that the level of infrastructure preparedness isn’t, isn’t there, right? A lot of our infrastructure was built for a different climate than it’s seeing now. And so we’re seeing infrastructure failures. We saw that out in the West coast, you know, in, um, in the atmospheric river. I see it in, uh, you know, in downtown Toronto. We’re getting more extreme summer rainfall events. And, and so the storm sewers can’t handle it, and there’s backup into people’s basements. And so I think we need to harden our infrastructure. That’s the adaptation part of it, right? To adapt to the changing climate. But I think the real way to solve this problem is to mitigate future climate change. And that means reducing our emissions of carbon dioxide. Because if we’re seeing this at 1.1 degree, right at 1.5 degrees, it’s gonna be more and more extreme. And of course then at two degrees it’s gonna be even more extreme. And so we need to sort of, uh, we can’t do much about the heat that’s in the system now that’s been baked in over the last 150 years. But we can do something about any future warming, and that’s under our control. If we’re serious and we start, you know, reducing our emissions of carbon dioxide, we can have a more, a climate, which is not so extreme in, in the future. The challenge is, is that, you know, I I, I studied with, uh, a scientist who won the Nobel Prize in physics a couple years ago for work you did in 1960s predicting what doubling c o two would do. So the science was settled in the 1960s. The first un climate conference was in nine, I think 1993. If we’re just sort of nice and say, let’s say 1993 was when it came to the attention of let’s say policymakers. We’ve had 30 years right. To do something and we haven’t done anything. So going carbon neutral by 2050 isn’t really gonna solve the problem because we’re gonna have an extra 20, 25 years of heating in the, in the system. It’s gonna be more extreme. I understand it’s really hard. I totally get that. But we really gotta get at it or, uh, you know, it’s gonna be quite extreme. And I don’t, you know, I’m, I’m nearing the end of my life. I’m not gonna be here for very long. I’ve got two grandchildren who are visiting me today. They’re 18 months old, and I really worry about the, the world they’re gonna live in. Yeah. ’cause it’s gonna be, I think, a really much more extreme inhospitable place than the one that, that, that I got from my grandparents, right? And so I think, you know, politicians tend to be focused on, you know, the next election cycle, whatever, we really gotta think longer term. We gotta think about our grandchildren and our great-grandchildren and what are we gonna leave them, because I don’t think it’s really fair to them that they bear the brunt of sorts, of the excesses that, that, that my generation put on this earth. So that’s really what bothers me is just what world are they gonna inhabit? And that really does bother me.

Jordan Yep. Well, buckle up. Kent. Thank you so much for explaining this to us.

Kent Moore It’s my pleasure.

Jordan Dr. Kent Moore from the University of Toronto. That was the big story. For more from us, you can head to the big story podcast.ca. If you type in British Columbia, you can take a look at the episode I mentioned off the top about the future of the climate crisis out west. I feel like we’re gonna do a lot more of these future of the climate crisis episodes. I hope you’re as scared and terrified of that as I am. But we’ll do them. ’cause this is the news, especially right now. You can find the big story at the Big Story Fpn on Twitter, email us hello at the big story podcast.ca, and you can always call and leave a voicemail, (416) 935-5935. If you’re listening to this podcast in an app that lets you leave a rating or a review, we’d be honoured if you did. If you have a friend who likes podcasts and likes the news and happens to be Canadian and you haven’t told them about us yet, we’d appreciate that as well. Thanks for listening. I’m Jordan Heath-Rawlings. We’ll talk tomorrow.