This is Dr. Emily Schoerning with AR, and I’d like to say hello to all our friends in Tennessee. Now this is a state where we’re already seeing the effects of extreme storms, very sad stories out of Tennessee about people being drowned in these extreme storms. I’m going to help you build a picture of what the federal government projects Tennessee will be like in 2050, and we’ll highlight disaster preparedness in that context.
First things first, I want to show you why many people in Tennessee might reasonably be skeptical about climate change. Check out this map (759), we can see that the number of really hot days in Tennessee has dropped pretty substantially over the past hundred years. We’re talking like a 70% drop in really hot days. So if your neighbor has felt that drop over the course of their lifetime, and they tell you they don’t believe in climate change, I hope that data makes it easier to see where they’re coming from.
When we look at what has changed in the Southeast over the last hundred years, it’s more subtle, and many people won’t have noticed it yet. It’s changes in the nighttime temperatures, and those you can see have increased pretty dramatically here in Tennessee. They are projected to increase more, let’s check it out (763). By 2050, particularly over here on the western edge of the state, you’re going to have a lot of summer nights where a person is going to need air conditioning, is going to need help to get their body temperature cooled down in the nighttime so they can maintain their health, keep working the next day.
We can tolerate a fair amount of daytime heat stress if our bodies can cool down at night. But there is a limit to our tolerance for daytime heat, right? Let’s look at our projected summer heat duration (HEAT)
You can see that today there’s a lot of variation in how the summer feels around the state, mostly based on the topography. Some urban heat island effect too, I think, down here by Memphis. And you can see that there is an expectation that the summer will feel longer and hotter as we move towards 2050. Memphis will feel more like Jackson, Mississippi, and Knoxville will feel more like Memphis feels today. There’ll still be a cooling effect in the mountains, but there’s enough more heat that I’d worry about some of your higher-elevation plants and trees.
If your higher-elevation forests have trouble, that can lead to increased fire danger. We’ve seen that out west, where trees on the mountains have died from the changes. Let me tell you up in the Sierras, up by Yosemite, it’s been just terrible tree death, a tragedy you had to witness to believe to scale of it. And then after the tree death, there have been these massive wildfires. We can keep what’s happening in the west in mind, and learn from it. That scale of wildfire isn’t a definite problem, in Tennessee. Not yet, and hopefully it won’t happen. But it’s an issue to keep a real serious eye on.
When you think about disaster preparedness, it looks different in different parts of the country, and we feel differently about disasters depending on what you’re used to. If I woke up to an earthquake in Iowa, I’d be freaking out. But people who’ve been in California a long time, a little earthquake, they just roll over and go back to sleep. In Tennessee, there are plenty of extreme situations for which you are already prepared. But the disastrous flash floods that have started, there’s a current lack of preparation on an individual and a community level, and both of those are crucial. And this potential for wildfire, this issue to keep an eye on, it shows us another event where lives will be lost that could have been saved with individual and community preparation.
Keeping preparation in mind, and thinking about how much hotter it could get, it’s worth considering the fact that Tennessee is on the edge of the area where we might worry about dangerous wet bulb temperatures in the summer. You’ve probably heard that phrase, wet bulb temperature. Everyone who’s experienced humidity knows that it makes heat feel different. A 94 degree day in say New Mexico, with low humidity, you can be pretty comfortable. Go sit out in the shade, have a cool drink, you feel great. But 94 degree day, high humidity? You go sit outside, you’re getting stuck to the chair. Gross. And if it gets too hot- and that is 95 degrees. That’s the magic number, people. You can die in 95 degree weather if it’s really humid out.
Of course, that magic number goes higher as the humidity goes down, but I feel like if I’m gonna store one number in my brain, it might as well be the lower end of the danger scale, bottom of the red zone. Particularly if your family includes little children or people over 60. Their heat tolerance is more limited and it’s not worth pushing their tolerance if it’s 95 or over.
So if we see heat waves as part of our extreme weather in the future, which is likely, you can readily imagine that we could get a heat wave of 100 degrees in this area, and if it was also very humid that heat would kill people who didn’t have a way to cool down. You’ll need functional air conditioning. It’s not a luxury in this future we’re looking at, it’s a necessity. And so power is a necessity. Strengthening that power grid to make it resilient to heat is going to be very important for Tenneesee, and so are community approaches to cooling. There need to be places people can go to get cool if their power fails. That doesn’t need to be something new- think libraries, think good places we’ve already got. We need to hang on to those great community institutions and help them get stronger.
There’s also a low-power solution to escaping a potentially fatal heatwave, and that’s going underground. If your home has a deep basement, a 1890-1910 style basement that was dug deep so as to be used for food storage, you are probably aware of how much cooler that basement can be, even on very hot days. If your power goes out during a dangerous heatwave, and you’re concerned about getting to safety, you don’t want to leave your property, get down in the basement and don’t do much. Work on getting the power fixed after the sun goes down.
We can get very scared when we hear about new threats, like these potentially very dangerous heat waves, potential wildfires. But if you make a plan for them, just like how you have a plan for a tornado, for a fire, for any disaster, you have a much better ability to respond to the danger.
Let’s take just a second and look at our current patterns for extreme weather in the state (760). You can see that there’s a lot of variation, some areas seeing more extreme rain and some areas seeing more drought. What you want to look for on this map is areas where those circles are paler. There in the center of the state, you’ve got a nice place, pretty land, and so far no trend towards really dramatic weather changes. Right now, scientists aren’t great at predicting specific weather patterns way far out, all we can do is look at current trends and say it seems likely those trends will continue. So you can see here in the northeast corner, if you want to dig in here, you’ve gotta get ready for very serious rainstorms. And you might anticipate more droughts up here by Kentucky. I do want to refocus on this central region of mild trends, though, I think this is a nice place, and I want to show you, it’s also got a pretty stable plant hardiness zone. (HARDI)
Overall, we’re expecting pretty good stability in plant hardiness zone in Tennessee. Right now, you can see most of the state is zone 7, with some cooler winters up in the higher elevations, little warmer winter by Memphis. And there’s not a huge change, looking ahead in the forecast. We’re going to stay in zone 7 for most of the state, some expansion of that zone 8 territory. Not bad, some of the best conservation we’re seeing in the Southeastern region.
Okay. We covered a lot of ground here, let’s try and pull it together. Overall, the outlook is challenging. But it’s not as rough as for many other parts of the country, and we can see a lot of what we need to do to get ready. There’s work to do here, and a lot of it is good paying work. HVAC, electrical infrastructure, those are good jobs.
You do have new threats you need to prepare for in Tennessee. You might need to prepare for changing wildfire patterns if, and this is a big if, you start to see a lot of tree death in your higher-elevation areas. You’re going to need a solid power grid, because this state is going to need more cooling. Especially in Memphis, the nighttime heat, the projected longer summer, it’s one of the southeastern cities seeing the biggest potential heat challenges. Seriously, Memphis, it’s you and Raleigh, the feds are most worried about the two of you in the entire Southeast.
On the bright side, that area in central Tennessee is really looking very nice. Great relative stability on a lot of different fronts. I’m also interested in Knoxville. Knoxville’s got a relatively pleasant outlook. Not such a big heatup, not a lot of deluge-type rain events so far. Knoxville might be looking at some real potential for growth. There are a lot of people who are going to want to stay in a place that feels, you know, Southern, that has some pretty traditional vibes, some good music. As people are going to need to come in off the coast, I think you have some destination potential.
This is Dr. Schoerning with AR, signing out. Please like and subscribe, help get the message out there. There is hope. We can prepare for what’s coming. Let’s get ready.