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Brian Lehrer: Brian Lehrer, on WNYC. You could be forgiven if you feel like our weather in the New York area recently has been sort of biblical. Right? We were just in the extreme heat, there were the Canadian wildfires causing air pollution alerts. Today, it's predicted we'll have the floods. The frequency of extreme weather events like these correlates with the 10 hottest years on record being the last 10 years, even as the EPA announced this week that it wants to stop regulating greenhouse gases at all.

We'll get a take now on the interconnectedness between the fires up there, the air quality index here, and the pattern of heat and drenching rains, from Radley Horton, professor of Climate at Columbia University's Climate School, among other things from his bio page, Professor Horton was a convening lead author for the federal government's Third National Climate Assessment, published in 2014, and very relevant to our local area.

He is currently the principal investigator for the National Oceanic and Atmospheric Administration Climate Adaptation Partnerships-funded Consortium for Climate Risk in the Urban Northeast. Professor Horton, thanks for some time today. Welcome back to WNYC.

Radley Horton: Hi Brian, nice to talk to you again.

Brian Lehrer: I crunched some numbers this morning on a century of temperature change in Central Park. I think listeners will find it really interesting. I know you know all this, but before we even get to that, I think our listeners might be interested in whether that bio of yours that I just read out still applies, with all the cuts to so much that's climate and weather related. Does NOAA, the National Atmospheric and Oceanic Administration, still have a consortium for Climate Risk in the Urban Northeast?

Radley Horton: Yes, great question. We still do, as of today, but as you know, not all scientists, not all people at this interface between our government funded research, our government science and our academic science, a lot have been very seriously affected, and also, of course, the public at large affected as well by these cuts. It's cuts to federal workforce, it's federal workforce losing access to the buildings they've worked in, access to the data they've used.

The National Climate Assessment webpage has gone dark, as you know, so challenging times. This NOAA program you referenced is still active and I believe more important than ever.

Brian Lehrer: What does it do? The Consortium for Climate Risk in the Urban Northeast. Briefly, what does it do and how do you do it?

Radley Horton: Fundamentally, this is about the link between our understanding of physical hazards, so everything from weather forecasts of the types of extreme events that you mentioned, through to the idea with climate change and increasing greenhouse gases, how are those risks going to shift? How much more heat waves are we going to see, how much is rain going to change, for example? We go that extra step and also look into the sectoral impacts, right?

Getting beyond just the climate science, to ask which populations are most vulnerable, for example, in New York City. What are the complex ways that different sectors are going to interact in their impacts? Everything from the odds of the power going out during a heat wave to effects on our infrastructure, our transportation. It's that translation of climate science, working with that sectoral expertise, thinking about vulnerability, and then, most centrally, engaging all the way to the policy questions.

How do we make our city more resilient? How do we pursue our long term goals, not just reducing climate risks, but other goals for the city in that long term context, but with the comprehension that the statistics of extreme weather events have changed, the dice have been loaded by climate change.

Brian Lehrer: We're going to get right to some of those statistics. I'll just say one more thing about the politics of the moment and not make you respond, because you're a scientist, not a politician. Maybe the heavy weather in Texas this summer, deep in the heart of red America, is going to save some of these government functions. Here's a story from ABC News just last week.

It says for fiscal year 2026, which begins October 1st, the Trump administration proposed cutting Noah's budget by roughly 25%, including elimination of its research division. I'm going to say that again, the elimination of its research division, and it goes on, plus major reductions to other key offices such as the National Centers for Environmental Information, the world's largest provider of weather and climate data.

The story also says, "Lawmakers from both parties have so far rejected steep cuts to NOAA proposed by the Trump administration and reiterated their support for a fully staffed National Weather Service." All right, so this morning, I took out my handy dandy calculator app and went to the National Weather Service page, which is still there, that has average monthly temperatures for Central Park, for every month going back to 1869, and for the month of July, rounding to the nearest whole number.

Listeners, you can do this much math, you can bear with this, you're not going to get lost. The average temperature for all hours of the day, all average together, in July 1869, was 73 degrees. For all of the 1920s, moving ahead by 50 years, the average July temperature was up 2 degrees, to 75 degrees. Jumping ahead another 50 years to the 1970s, the average temperature for the month jumped by another 2 degrees, to 77.

For this decade so far, through last year, they don't have this year yet, it's still July, at least till tonight, the average July temperature in Central Park in this decade has been 79 degrees. Plus 2 yet again. To review, 73 degrees on average, all July, in the 1860s, 75 degrees in the 1920s, 77 degrees in the 1970s, 79 degrees now. Professor, here's the stupidest question I'll ask of any guest all week. Do you see a trend?

Radley Horton: Well, you articulated better than I could have, right? It's steady across these decades. Yes, very powerful trend, right. You're describing the average temperatures in our hottest month of the year. Of course, during that hottest month of the year, we can further deconstruct the data and look at the absolute hottest days that are getting experienced, for example, and there, too, we see these upward, trends where those times that are particularly dangerous, right?

When everybody needs that air conditioning, when it's dangerous for people to be working outdoors, when economic productivity is affected by those high temperatures. We're seeing the increases there too, in those hottest days. But you're absolutely right. This is not something that can be explained away by solely something like the urban heat island, during some of those earlier years you were talking about, we did see cutting down of some forests over parts of the greater New York area.

Most of what you're seeing in those more recent decades, we already had our urban surface, urban canopy. This is the effects of more greenhouse gases in the atmosphere due to human activities priming the pump for more of these really hot days. One thing we're looking very closely at is these exceptional ocean temperatures that we've seen, really across the globe, over the last few years. To what extent are those feeding some other changes in these statistics that you alluded to?

It's not just average temperature. It's also-- how is humidity changing? How are the combinations of temperature and humidity at night changing? It's harder to say that a trend is due to climate change when you use a more esoteric variable, something like temperature and humidity together. Putting all the data together, we're nevertheless seeing that people's perceptions are right. There aren't as many fresh, cool overnights as there used to be.

Humidity is creeping up across the Northern Hemisphere, and that's particularly dangerous for populations. Not just the heat, but the humidity, too. It is increasing as the oceans warm and as we increase greenhouse gases.

Brian Lehrer: We have more not that esoteric math to do. We will take it right to the current conditions of this week with the heat, the humidity, the air quality. We're definitely going to talk about the air quality in relationship to the wildfires, and another day of trenching and flooding rains expected, beginning this afternoon, with our guest from the Columbia University Climate School.

We can take your phone calls, listeners, weather, climate, for Radley Horton, professor of climate at Columbia University's Climate School and a convening lead author for the federal government's Third National Climate Assessment. 212-433-WNYC. 212-433-9692. Call or text to ask about the heat, the wildfires, the air quality, the flooding rains or anything else related. Stay with us.

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Brian Lehrer: Brian Lehrer, on WNYC, as we continue with Radley Horton, professor of climate at Columbia University's Climate School and, among other things, a convening lead author for the federal government's Third National Climate Assessment published in 2014, and very relevant to our local area. He is currently the principal investigator for the National Oceanic and Atmospheric Administration Climate Adaptation Partnership-funded. This is a mouthful, this job you have.

Consortium for Climate Risk in the Urban Northeast. There, I got through it. Let me ask you something about that, relevant to the stats we were going over a minute ago, your Consortium for Climate Risk in the Urban Northeast. What can you say about the effects on people of this gradual change in temperature that we went through the data on before the break? In 1869, yes, there were cooler summers, but there wasn't even such a thing as air conditioning. How do you measure the human impact in heat related deaths or anything else?

Radley Horton: Yes, that's a great question. One of the elements to that question is how many things have changed since 1870 or so. We've had this warming climate, but we've also seen changes and, in some cases, improvements overall, in things like air quality, at least in some of the more recent decades. We've also seen changes in overall public health across the city. Better warnings in advance of these extremes now.

Putting all these things together is a complicated tapestry. How has the total population of the city changed, for example. The parts that we really focus on and where the data is crystal clear is increasing greenhouse gases giving us far more of these extreme heat days, far more heavy rain events, and as sea levels rise, even just gradually, it means when a storm comes along, a coastal storm, the water penetrates that much further inland.

Causing more damage, potentially causing death and destruction, as we've seen, as that higher water allows more waves and faster movement of that water. These things can be directly linked to climate change. You're right, also, towards your point, we're now starting to see some resilience, some adaptation to that changing climate. Through our consortium, we've been working with New York City government and communities now for 15 years or so, including the Sandy Recovery.

There is now that opportunity to observe which adaptation strategies are working and which ones have been insufficient and need to be adapted, especially for the most vulnerable.

Brian Lehrer: I'm going to take a call from Carrie, in Greenwich Village, who I think has something interesting to say about the very fact that that that historical National Weather Service temperature chart for New York City measures it in Central Park, in particular. Carrie, you're on WNYC. Thank you for calling in.

Carrie: Thank you very much. This is a great segment. I'm just curious because, having spent a lot of time in my neighborhood, other neighborhoods, and in Central Park, Central Park is always far cooler, owing to trees, it being a bit of an oasis, et cetera. It just seems that 79 degrees now, in Central Park, equals a lot harder in other parts of the city, and [inaudible 00:13:14] address that.

Brian Lehrer: It's a great point. If that temperature curve, up and up and up in the last 50 years, in Central Park, holds true, what would it look like in central Bronx?

Radley Horton: Yes, great question. All of our official weather gauges, our official ways to try to measure temperature, try to keep the sunlight out. They're meant to be in shade, for example. Practically speaking, you're absolutely right that when you have a whole neighborhood with a lot more tree cover than another neighborhood, that is going to affect the overall temperature.

Central Park, all things being equal, is going to be a little cooler than some of those other neighborhoods, even the way a classic weather thermometer, used by the weather service, would measure them. I think an even more important point that you're alluding to is what do people actually experience out on the ground? Whether they're in whatever neighborhood they're in in the city, if they're actually walking on the pavement, they're going to be getting additional heat coming from that pavement.

They're going to probably be in the sunlight in some neighborhoods more than others. Those things mean that individuals are actually going to be experiencing very different conditions than our thermometers that we use with the weather service are even trying to capture. The lived experience really does vary, as you say, by neighborhood, due to shade, due to what type of job somebody has, what kind of clothing they need to wear, how much they need to exert themselves, whether they're getting access to breeze, all those things.

Brian Lehrer: Want to hear a text from a skeptic? Listener writes, "To study a 2 degree rise actually indicates that there is no contribution for human activity because it's so steady." Actually, what we documented in that curve was a 6 degree rise from 1869 through now, a 6 degree rise in the average temperature for July, but I think that the listener would make the same point.

To study that rise indicates there is no contribution for human activity because it's so steady, as opposed to spikes where you see a dramatic change from 150 years to the next. What do you say to that?

Radley Horton: Yes, there's a lot of ways to go with that comment, I think, to really understand the global effect of increasing greenhouse gases. These greenhouse gases are well mixed, meaning that we put them all over the atmosphere. You don't just focus on the one city, right? You look at the trends across the globe. Here, you can really see that the majority of the warming has happened over the last 40 years or so. That's been very robust, not just in one place, but across pretty much the entire globe.

Of course, it's not just air temperature. We're also seeing other things happening that are exactly what we'd expect if greenhouse gases were causing the warming as opposed to other phenomena, like changes in the amount of sunlight, for example. The predictions with greenhouse gas contributions specifically are, the polar regions should warm more than the tropics. That's what we've observed, and that once you get up above 30,000ft or a little bit higher, you should actually start to see some cooling. That's what we've observed.

Then we could also look at things-- what we call things like phenology. When spring starts, when fall happens, changes in snow cover, changes in the amount of moisture in the atmosphere. All these things are happening in ways that are consistent with what for over 100 years or so people have anticipated in terms of why greenhouse gases should warm the atmosphere. It's incredibly simple and elementary physics of how they work.

Where it gets a little complicated is the secondary effects. Once you get that warming, how will the planet respond? How will clouds change? Those real research questions are second order. The basic physics of why greenhouse gases should warm the planet and the types of evidence that I just described are extremely robust in just some of the ways that I described.

Brian Lehrer: If the average has gone up 6 degrees for the month of July in New York in 150 years, and the country is doubling down on fossil fuels now, if the status quo continues-- I don't know if you have models that project what New York City might be like in July, in another 50, 100, or 150 years.

Radley Horton: Yes. That types of data is in these New York City Panel on Climate Change reports that have come out every three or four years or so. I'd encourage folks to go look at those. Yes, you're absolutely right. What sound like small shifts in average conditions, which I think is what that last caller was sort of leaning into. When you hear one or two degrees average, it sounds like nothing, but it profoundly shifts the statistics.

It could mean, if we get just a few more degrees of warming, by, say, 2050 or so, we might actually be getting two or three times as many hot days, days over 90 degrees, as we did in the past. It means that we might see these coastal flood events that used to happen once every 10 years, happening every couple years. Just with these small shifts in the averages, they profoundly shift the frequency of the extremes. What I described, in a sense, is like a best case scenario.

It's essentially the idea that, what if the statistics don't change at all? What if the variability doesn't change at all? What if we just warmed everything every day, by that, say, two degrees? What would the effects be? The other thing that could happen with climate change, and this is where we get to things that are a little more uncertain, but very possible. It's not just the average that changes, but what if key processes change? What if we find that our hottest days actually warm more than the average day?

That's the kind of thing that is not a sure thing, but from a risk management perspective, if you're worried about fire risk, if we're worried about running out of water, if we're worried about our most vulnerable populations, if we're worried about trying to estimate the odds of a need for air conditioning that exceed what we're able to provide, we need to be open and really explore those ideas about either worst case scenarios or just lower probability, very high consequence events that we're starting to worry aren't quite as low probability as we thought.

A classic example of that is what we're seeing with these fires, including across Canada. The last three years have really looked like what we call almost like a step function. It's very, very different fire behavior than we saw in the past. Fire starting earlier, burning in more areas, and it's far more than what happened in the past. Now, if it's just a few years, and if it's just one country, some of that can be variability as opposed to a signal or trend due to greenhouse gases.

When we look across the entire globe and we see more and more of this surprising behavior, we start to worry that maybe it's not just the average that's changing, but an actual shift in the statistics. Meaning that what we used to say is very low probability, but we're thinking about anyway, because it'd be catastrophic if it would happen, now suddenly starts to look not just catastrophic if it would happen, but more likely than we thought it was. Something like these fires in Canada, I think are a classic example.

Can't say for sure that more of these events hitting New York is climate change. That's too early to say that, but from a risk management perspective, people haven't thought a lot about what faraway fires could mean for cities, how the combination of heat waves with these poor air quality events from forest fires could in a nonlinear way more than double the effects that you would see individually on people's health, from, say, fires or people's health from poor air quality.

If you're any type of risk manager, someone looking to protect vulnerable populations, an insurer, or a reinsurer, there's this concern that these new correlations, these new relationships are starting to emerge due to climate change that we're quite simply not prepared for. Especially if, to the extent we've even thought about climate change, we've tended to think about it just, how is it going to affect our city, and just the variables we usually think about.

Brian Lehrer: As we talk about the heat, the wildfires, the air quality, the flooding rains, especially in the context of longer term trends, with our guest from Columbia University's Climate School, Professor Radley Horton. 212-433-WNYC. I mentioned in the intro, at the top of the segment, that the 10 hottest years on record, that's the average temperature all year, for everywhere on Earth, all 10 of the hottest years on record have been the last 10 years.

This is a New York Times Headline, folks, if you don't know this, from March of this year, Earth's 10 hottest years on record are the last 10. Very straightforward, right? The simplest stat I will cite in this whole math encumbered segment. That stat came from the World Meteorological Association organization. Earth's 10 hottest years on record are the last 10. Getting to the weather we've been living through this week.

The last time you were on this show, professor, you probably don't remember, was in 2012, shortly after Superstorm Sandy. It seems to me, looking back, like that was a turning point for climate change awareness in the New York area, because Sandy was unlike storms that came before. Looking back with 13 years of hindsight, was it unlike storms that we had had before, and maybe more important, did it start a new era of local weather in these hottest 10 years on record that have occurred since?

Radley Horton: Yes, great question. There's so much to unpack there. I think for starters, it absolutely led to a change in society's awareness of these risks. It was a teachable moment where, suddenly, people appreciated vulnerabilities to extreme weather that they didn't realize that New York City had. You see this all around the globe. Even if the experts say that there's a risk, people need to experience it, they need to see it with their own eyes, usually to appreciate the vulnerability and to be able to muster up the resources to invest in protection.

For New York City, absolutely. On the one hand, even before Sandy, in 2012, New York City was taking an honest look at these risks. We already had the New York City panel on Climate Change. It's also fair to say that once Sandy happened, there was a deeper engagement and more of an understanding about the need to spend money. The $20 billion post Sandy plan for New York, which wasn't perfect, but clearly a major step towards resilience.

I think it did much as, several years later, Covid had a similar effect, even though very different phenomenon. It got people to be able to say, "What are these knock on effects that these events could have? How do we scenario play and understand interconnections to understand the vulnerabilities that are going to emerge, and just what might happen?" Sandy was a big surprise to most.

The way that storm happened so late in the year, took the approach path that it did from the ocean, those things were surprises, although getting a big storm was not a surprise. Since then, yes, I think now we're really open to emerging new risks. Look at these incredibly heavy rain events. I believe that the three wettest hours that New York City has experienced have all happened in the last four years or so.

There's all sorts of problems with using hourly data, but it's also true that if we can say that for one location like Central Park, the idea that two inches of rain have happened three times in the last four years, roughly, and didn't really happen before that, that's a huge statistics. Similarly--

Brian Lehrer: [crosstalk] See if we get that again today, right? The city is warning of dangerous and travel-hampering flooding.

Radley Horton: What we can say for sure is that having more of this heat and humidity sets the conditions where it's easier for those types of events to happen. Again, I'm not saying that this trend, these three events are solely due to climate change, but it's helping us appreciate these emerging vulnerabilities and try to better prepare. The question is, what else is out there? We talked about this wildfire smoke. What else are we not prepared for?

I think you're starting to see more efforts to consider a broader range of hazards, but also just to think about resilience in ways that are like-- what are the things we can do to protect the vulnerable populations, no matter what weather we get, exactly? Whether that's things like better early warning systems or improving people's overall health, those types of things.

Brian Lehrer: Amy in Brooklyn has a wildfires question. Amy, you're on WNYC. Hello.

Amy: Hi. My moment of waking up to air quality issues was the event that we experienced two years ago, where I discovered this website, Firesmoke.ca, it's from Canada, where you can see a forecast of the smoke coming in from Canada. What this map has shown me, however, is the number of wildfires that are happening all over the country, that are happening, there's like 24 right now, showing up near Philadelphia, New Jersey, 108 in Georgia and [inaudible 00:27:25].

Why isn't there awareness around wildfires not happening just in Canada or on the Pacific coast, but that's happening everywhere. Also, the political side of it is why aren't people going after administration and saying-- Look, these wildfires, there's [inaudible 00:27:44] in the middle of the country, near St. Louis. Why aren't people going after Trump to say, "What are you doing about all of these wildfires?"

Brian Lehrer: Professor?

Radley Horton: Yes, I think for me, starting from the physical principles is really useful here. There have always been small fires at times, in various places. There have always been a lot of things that can cause fires. It's also true that we are seeing more of these large, really intense fires than we have in the past. It isn't just Canada. That's right. We also see plausible physical mechanisms for why that's happening.

The big concerns, we're talking about some of these surprises and tail risks as we have been, is that I think the scientific community was slow to appreciate, again, how this gradual increase in air temperatures, in a nonlinear way, has led to a huge increase in fire risk. It's intuitive to think fire is mostly going to be about how much rainfall you get, and over the short term, rainfall is really important.

It's also true we're realizing that these hot summers, and even things like snow melting earlier in the season than it used to, prime the pump, because a warmer atmosphere can hold more moisture. Even if you got the same amount of rainfall you got in the past, that warmer atmosphere is going to be more effective at sucking that moisture out of the vegetation, out of our crops, out of our soil. I can't say that's the only thing that's leading to more of these fires, but it's a powerful factor that's been underestimated.

As we turn up the dial in the future, with higher greenhouse gas concentrations, it could continue to surprise us in that direction. I think more broadly, towards the questions around risk and policy that you brought up, this is a hugely underestimated risk. A lot of homeowners are living in at risk areas. They didn't know it when they bought, or people who started renting their properties. There are some communities that are learning that there's only one or two routes out of their community.

There are major safety issues here in addition to the fact that for a lot of people, their primary asset, and so much more, is their home. It's also affecting the safety of people working outdoors, exposed to the smoke, including far downstream, as we've seen. I think it is a factor that is going to keep reminding people that we need both to be studying these types of events and also to be coming up with policies, including dramatically reducing our greenhouse gas emissions so that we avoid these scenarios of really high warming.

Brian Lehrer: Yes. The conditions we had for the last three days, heat indexes over 100, and AQI, air quality index, over 100. The combination of high heat and air quality, and on that AQI scale that they use, over 100 is considered where they issue an alert for sensitive groups. I don't remember hearing air quality alerts very much until just a few years ago, with that big round of Canadian wildfires that turned the city's air orange for that day in June, a couple of years ago.

Did we always have unacceptable air quality days in the summer, but they just didn't get as much media attention?

Radley Horton: I would say the answer to that is yes. I think it's also true that the horrific smoke, and particularly particulate matter 2.5, these small particles that happened in that early June fire, was pretty unprecedented, so both things are true. We've always had instances in the past where we had really bad air quality. It might not have been fires in the past, it might have been smog, it might have been these high pressure weather systems that can cause air to stagnate, pollution to stagnate near the surface.

As we all intuitively know, that those fires and the resulting smoke of early June 2023 did push awareness to a new level, but if there is a silver lining on this one, it's the growing awareness that pretty much any amount of small particles are really, really bad for all of us, but especially those of us with pre existing health conditions, or the really young, those with respiratory-- Yes.

Brian Lehrer: [crosstalk] On those small particles, I read that the danger to sensitive people is not from the haze we can see, it's from very small particles that we can't see when the fire related alerts are out there. Is that something you can explain in 30 seconds?

Radley Horton: Yes, minimally, but I'll try my best. Basically, these tiny particles, when we inhale, they're not captured by cilia, they're not captured by our bronchias. They can go deep into our lungs where they can cause damage and sometimes actually into our bloodstream. They lead to inflammation, long term health risks. Smoke can have a lot of other things in it besides these small particles.

What else is burning? Are there instances where we're seeing tragedies of homes burning that are putting other pollutants out there? These are also things that need to be part of the discussion going forward.

Brian Lehrer: Let me ask you one other thing from a listener, and then we're out of time. I think this comes from a listener who doesn't want everybody to have to give up the conveniences of fossil fuels, but still wants to deal with climate change. The question is about geoengineering, which, as I understand it, is engineering efforts like removing carbon dioxide from the atmosphere and other things like that rather than preventing it.

Is that something that you study at all, or that you consider a realistic way to mitigate the effects of climate change?

Radley Horton: Well, I think we have to study that, and we have to also study efforts that would block sunlight, another way to lower temperatures. I don't think either of those geoengineering approaches is going to help us much in the short term. There's a moral hazard too, right? They might prevent us from taking the immediate steps we need to reduce temperatures sooner, and to invest in adaptation.

There's a lot of downsides if we do those things. Even if you drop air temperatures by blocking sunlight, you're not going to get the rainfall patterns of the past. You're still going to get acidification of the oceans. We don't have the technology now to rapidly pull carbon out of the atmosphere. I personally think we should be investing in it because we need nonlinear surprises in the solution space.

Not just to counteract these scary hazards and impacts I've been talking about, but we also need the immediate steps that we can take right now, to drive down the cost of renewables, for example, that will give immediate air quality benefits, and where we basically know we can quickly see the improvements in emissions reductions. Given the scale of the problem, I don't think we should rule out considering broader approaches as well.

Brian Lehrer: Radley Horton, professor of climate at Columbia University's Climate School, and principal investigator for the Consortium for Climate Risk in the Urban Northeast. Thank you so much for joining us, and for all this information.

Radley Horton: Thank you, Brian.

 

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