Across the country, people are suffering as a result of increasingly extreme weather.
This summer, Allegheny County experienced its first ever Code Red Heat advisory amid a larger heatwave across much of the eastern and central United States. At the same time, devastating floods caused billions of dollars in damages in Texas, as part of a larger trend of more extreme rainstorms.
The Allegheny Front’s intern Kyra McCague recently spoke with Christopher Scott, the Maurice K. Goddard Chair in Forestry and Environmental Resource Conservation and a professor in Penn State University’s Department of Ecosystem Science and Management. Scott studies, among other things, climate-smart forestry and climate adaptation and resilience. He explained how recent severe weather events are connected to climate change.
LISTEN to the interview
Kyra McCague: With the recent heat wave in our region and the extreme flooding in central Texas, could you talk about the role that climate change played in those events?
Christopher Scott: Those are two separate events. They’re all part of a broader North American continental scale set of climate impacts, which is important to recognize, are driven and accentuated by climate change.
Climate change is characterized both by general trends in warming over time, the average temperature of the planet, and importantly, the sea surface and the land surface [temperatures] are rising over time. There are cold dips and there are warm spells. In general, there is an inexorable march of increased temperatures, winter and summer, spring and fall, over time, and accentuated, you can clearly see, by human activities in the present, over several decades.
The impact of climate change on precipitation is more extremes, so higher intensity more prolonged periods of very heavy precipitation, but they could be interspersed by periods of drought.
The impact of climate change on precipitation is more extremes, so higher intensity more prolonged periods of very heavy precipitation, but they could be interspersed by periods of drought. And so low extremes, no rainfall at all, high extremes, really intense cloud bursts of the kind that the Texas Hill country saw, and that also are a feature of some of the precipitation patterns here in the Northeast.
Kyra McCague: So how do scientists connect specific extreme weather events to climate change?
Christopher Scott: The way to do that is to look at the overall frequency, and there’s a whole set of analyses that are called extreme precipitation or flood frequency analysis. Most of the public has heard about this when we hear about, “Oh, it was a 100-year storm, or it was 10-year or it a 500-year storm, and are we prepared for that?”
You do a statistical analysis to be able to say, what was the extreme, highest amount of flow of water that we got or the highest amount of rain that we’ve got all of last year, all the way back to the beginning of our record. Based on the 30, 40, 50, or 100 years of record that we have, here’s how those extremes plot out from the driest, lowest, to the most extreme, highest amount of precipitation.
Statistical analysts of this kind of stuff have spent their careers with lots of scientific cross-checking called the peer review process to say that the Guadalupe River in Kerr County, Texas, has this kind of an expectation of flow. That doesn’t mean that once they get that 100-year event, they’re good for another 100 years – you can have two years in a row.
Now, here’s the other thing. As you get more extreme precipitation, you’re actually expanding that record. And if we got lots of high precipitation events that account for our current and next year and the following year and so forth, the distribution of those numbers will increase.
Kyra McCague: We recently talked with people in the street who pointed to Earth’s natural cycles as a reason for warming. What would you say to that argument?
Christopher Scott: Earth certainly has natural cycles. The Earth system on these trends of carbon dioxide concentrations, rainfall, and temperature. These are the three main signals we’ve been talking about today. Through all of the science available, it is incontrovertible that the acceleration of those processes took off in the 1950s and 60s, and it remains accelerating today.
The only blip we saw was during COVID when everybody was staying at home. They were not taking jet flights; they were out driving their cars around. Some of those greenhouse gas signals did take a blip, but we have more than “caught up” or recovered back to the accelerating trend. And so yes, there is natural variability. Humans have incontrovertibly accelerated the process. And that is linked to greenhouse gas emissions of carbon dioxide, methane, nitrous, and sulfur oxides.
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Kyra McCague: What impacts can we expect to see on human health, infrastructure, and economies related to climate-induced weather events in the coming years? Is the effect accelerating?
Christopher Scott: The effects are accelerating in the sense that the warming process and the more extreme precipitation that I mentioned at the beginning of our conversation here are accentuating. The effects certainly will increase, and they will see more high-flow and volume-type of events increasing over time.
Health effects are of multiple kinds. The actual flood effects are clearly the damage, loss of life, but also if properties are flooded out seasonally, but with increasing frequency, your basements are flooded. You could have problems associated with mold, indoor air quality, and rotting structures.
On the other side of the extremes, when it doesn’t rain, we’ll have dry effects. Parts of Canada have been burning, and so air quality associated with wildfires is also a critically important public health issue associated with climate change.
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Let’s talk about public infrastructure, roads, bridges, wastewater treatment plants, things of that kind.
Many of those are built in and across the floodplain because we humans need to get across those areas with our roads. Wastewater treatment plans are a particular challenge. They are located at the lowest point in the community, but it’s a flood risk because that type of infrastructure sits in harm’s way.
The second thing I’d like to say is we have an aging infrastructure problem, especially on the East Coast. We have bridges and roads and things that are hundreds of years old. That stuff ages and you’ve got to do repairs, and you’ve got to protect it not only from the flood that’s coming, but from a general process of wear and tear in terms of what’s expected in the future.
If every local township had to have its own weather prediction system and its own flood response system and its own flood recovery system, there’s a coordination issue.
Kyra McCague: And can you talk a little bit about how climate policy plays into this?
Christopher Scott: The concern that I have, and I’m really not trying to be overtly political about this, but I do think that the recent proclamations that the federal government is going to play less of a role in disaster prediction, preparedness, response, and recovery, and that a lot of it will be delegated to states and states will probably pass it down to local municipality and township levels.
If every local township had to have its own weather prediction system and its own flood response system and its own flood recovery system, there’s a coordination issue. Now, maybe it’s handled at a state level.
My challenge there is that there are states that are better off and have a better tax system, and they’re going to be the ones that’ll probably end up taking care of themselves. I think Pennsylvania’s good in that respect, better than many states.
Kyra McCague: So what can we do to mitigate those impacts, especially as you said, when the federal government and even some state government policies kind of deny these impacts of climate change or they don’t seek to solve the problem?
Christopher Scott: I think there’s a lot of academic and scientific work that goes into this. A lot of the leading science in this is done by the National Weather Service. In the private sector, this is being done increasingly by private weather service providers, AccuWeather, other kinds of groups like that, but also the insurance industry. They do a lot of technical financial analysis. There’s an installed brain trust that thinks about this. So let’s let some of the smart folks do this and let’s not silence and muzzle science. Let’s have open debates.
Society more broadly can realize that at some level, government does play a role. The private insurance industries and the private AccuWeathers and things like that are not going to pick up all of the responsibility if the government, from the federal to the state to the local level, entirely steps back.
That means public institutions have a critically important role, and we need to be strengthening our public institutions in terms of climate response and disaster response, not undercutting them and defunding them.
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Kyra McCague: You previously worked with FEMA and the National Weather Service – can you talk about what you took away from that experience?
Christopher Scott: I did work for the National Weather Service, I did work for FEMA, and that really gave me profound insight, but also conviction and being convinced that there are good and responsible folks working in those agencies and throwing them out, I think, does not solve the problem. I think it actually aggravates the problem further.
Christopher Scott is a professor of ecosystem science and management at Penn State University and the Maurice K. Goddard Chair in Forestry and Environmental Resource Conservation.
