That Blue Hue
Lake Tahoe is perhaps the most popular lake in the West. It sits at around 7,000 feet and attracts some 29 million visitors a year — more than three times Yosemite and Yellowstone national parks combined. What people don’t know is that the lake’s blue hue is also a barometer of how climate change is impacting our world.
[pop music fades in]
Ezra: There’s this moment when you drive over the ridge and the pristine blue water of Lake Tahoe comes into view. Every time I see it, it blows me away.
[traffic tape of Ezra driving - Ezra: “It looks like we’re moving…”]
Ezra: On this trip to Tahoe, I took the route on Highway 50 over Echo Pass. It’s on the south side of the lake.
[traffic tape of Ezra driving - Ezra: “There’s about 30 or 40 cars just waiting to go down the hill and probably the same or more going up.”]
[pop music ends]
Ezra: The last time I drove this route was a few months ago. It was winter then, but there wasn’t any snow. Come to think of it, I haven’t seen snow here in a decade.
[Hair In the Wind theme song slowly builds until the end of the intro]
Ezra: The year is 2099. And now that I’m over the pass, I don’t even want to open my windows. I can see why. So many cars and a forever cloud of smog and smoke. And there’s a red glow on the north side of the lake. Another wildfire is burning. The east side of the lake is already charred black. No matter where you go in California this summer, it seems like it’s been hotter than 110 degrees. But in South Lake Tahoe, it’s only going to be 95.
As I roll into the city, a sign says there’s nearly 100,000 people living here. In 2019, that same sign read about 23,000. Oh my gosh, there’s a giant black bear! It’s the biggest black bear I’ve ever seen and it’s devouring trash on the side of the road. I’m in bumper to bumper traffic and I’ve been driving for about 30 minutes just to find a parking spot. I think I can squeeze my car between those two rock climbing vans. You see, people are really into rock climbing here. It seems like Tahoe’s replaced Yosemite as the recreation Mecca.
[tape of car sound/door close/water ripple/birds in background]
Ezra: I finally plop my feet in the water, it’s not that icy, alpine cold I remember. It’s really warm. Cigarette butts, blunt wraps, and bottle caps and even a bag of chips are floating in the waves. When I was a kid, the lake was so clear you could see every piece of sand. But now, between the trash and the weeds, it’s so murky I can’t even see my feet. All this hasn’t stopped people though. From filling every inch of the beach with towels and fold-up chairs. There are so many boats, jet skiers and paddle boarders on the lake, it reminds me of the busiest Fourth of July ever. Everythings changed. Especially the color of the lake. It’s turning … green.
[music plays for a bit]
[Tahoeland voice montage]
Dan: These aren’t just theories anymore.
Stacy: I don’t want the snow to go away.
Simon: Yes, Tahoe will change.
Maryellen: I kind of feel like that endangered pika.
Don: Tahoe doesn’t control climate change it’s a victim of it.
[music beat drops and continues]
Ezra: From Capital Public Radio ... this is TahoeLand.
[montage of voices continues]
Laurel: It always snowed by the third weekend in September, but that doesn’t happen anymore.
McClintock: I want to see our forests restored. So, that Tahoe doesn’t burn the way Paradise did.
Maddie: Chasing the snow is a huge part.
Devin: It’s about the lake that’s why everyone is here.
Jesse: There are a lot of green lakes, there aren’t very many blue ones.
Ezra: I’m Ezra David Romero. What I just described was a worst case scenario of what Tahoe could look like by the end of the century. Today, Tahoe is a jewel in the sky, it’s one of the most popular lakes in the West. It has more visitors than Disneyland. But Tahoe could transform into something very different.
Scientists are predicting a place with less snow, lots of rain, more extreme wildfires — and tons more people. Tahoe’s also a petri dish for research. There's so much climate science going on. And that's why we're here: To see if Tahoe holds answers for how we can better adapt to this climate crisis. And it all begins and ends with the lake. Welcome to Tahoeland.
[tape of Ezra and Jesse jumping in lake]
Ezra: It is cold…
Ezra: So everybody comes to Lake Tahoe to have a bit of fun. But if you live here, like Jesse Patterson does, you have a boat and your bring friends out to cool off. The lake is normal, everyday life.
Ezra: Woo! Jump in!
Jesse jumps in: Jesse jumps in
Ezra: It’s pretty cold, huh?
[boat sounds build in background]
Ezra: Tahoe is going to change. Scientists predict a dark, dire future for this place. But we’re still gonna do all the things we love Tahoe for. It’s a lake, after all.
Jesse: We’re in D.L. Bliss State Park so on the west shore here. Right here about 350 feet. Go out a little bit further, and we’re in 700 feet. So it’s really deep, really close to shore.
[boat ambi continues under next track and cuts]
Ezra: Lake Tahoe’s beauty and appeal is universal. Sort of like Yosemite, which our first season of this podcast was all about. The lake is so popular there’s even a famous blue and white sticker about it. I’ve seen it around the world. It says Keep Tahoe Blue.
[music begins to fade in under bytes]
Jesse: I think you read it: Keep Tahoe Blue. And why wouldn't you want to do that if you've been here and seen it. It's like of course. Keep it just like this.
Ezra: What people don’t know is that the lake’s blue hue is also a barometer of how climate change is getting worse globally.
Jesse: Climate change is changing the petri dish too. We got warmer waters, we got different inputs, different ways we are going to use the lake.
Ezra: Let’s hold on a second, I understand a lot of you may have never been to Lake Tahoe. So here’s some essentials. It’s the largest alpine lake in North America and the second deepest at 1,645 feet. It’s 22 miles long and 72 miles around and straddles California and Nevada.
The place is rich with history and mystery. Everything from monsters in the water to scenes from the Godfather that were shot at the lake, and there are all kinds of rumors. Including one, that there’s a bunch of perfectly preserved dead bodies at the bottom of the lake. We’ll explore and fact check that myth at the end of the episode. It’s a segment we’re calling Tahoe Tidbit. So be sure to keep listening past the credits.
There are casinos, ski resorts and tons of places to play outdoors. More than 65,000 people call Tahoe home, and has 3 times more visitors every year than Yosemite and Yellowstone combined. But Lake Tahoe isn’t on the national park list.
Antonucci: And the reason is because it was heavily logged and damaged. Ultimately the National Park Service determined in the 1930s that Lake Tahoe simply lacked the pristine qualities that a national park should have.
Ezra: That’s Tahoe Environmental Historian Dave Antonucci. But even though Tahoe isn’t a national park … there’s a lot of national attention, especially from researchers trying to unlock the world’s climate crisis. And those scientists come from all over. Even, NASA.
[fast paced music continues]
Ezra: Okay, but you’re like Ezra why should I care about how climate change is altering Lake Tahoe? Here’s one reason: Imagine a wildfire like the Camp Fire in Paradise wiping out South Lake Tahoe, or runoff after a big snow year flooding Tahoe City. All of these potential changes matter to America’s most famous scientific institution. They’ve been collecting data on Tahoe every two minutes since 1999.
Ezra: I’m talking about NASA.
[tape of Ezra in car]
Siri: Starting route to Jet Propulsion Laboratory. Head east on Green Street.
[car takes off]
Ezra: Alright, here we go.
[pop music from car radio fades in]
Ezra: I drove from Sacramento to Pasadena where NASA’s West Coast operations are.
[pop music comes in and plays louder]
Ezra: NASA J-P-L NEXT EXIT!
Ezra: This is where I met Simon Hook. He’s the science division manager here. Simon’s in charge of a project studying large lakes.
[pop music from radio fades out]
Simon: And one of the great things about these big bodies of water is they act like these sentinels and they integrate all of these changes so we can look at them and say OK well this is kind of what's going on.
Ezra: When you think of Tahoe you don’t think of NASA and the MARS Rover, but there is so much science going on. Simon takes what he learns from Tahoe and applies it across the earth and to other planets.
Simon: We use Lake Tahoe as a reference point for many satellite measurements. Recently we just delivered some instruments to the International Space Station in particular an instrument called ECO STRESS the ecosystem space spaceport thermal radiometric experiment on space station. And we are using Lake Tahoe as a reference point for the measurements that we are making with that instrument throughout the world.
Ezra: NASA has four buoys on the lake with instruments measuring air and water temperature. They double-check satellite data.
Ezra: How fast is the lake changing?
Simon: When we talk about these temperature changes it's fractions of a degree. But what happens is that gets amplified over the whole region. And so those changes can affect the vegetation that's present at Lake Tahoe.
[electronic music fades in]
Simon: continued - Yes, Tahoe will change, but we want to be able to understand what changes are taking place, whether we need to intervene and do something about it because we want to get as much out of it as we possibly can.
[electronic music plays and fades out]
[water lapping sound begins]
Ezra: I want you to picture the bluest water you’ve ever seen. Parts of Lake Tahoe are so blue it reminds me of the Galapagos or the carribean. But that clarity’s changing. The lake’s lost 30 feet of clarity since 1968 and continues to lose about a foot a year.
Geoff: The water is getting warmer.
Ezra: Geoff Schladow and I are sitting on a dock on the west side of the lake. It’s so sunny and peaceful. Boats are scattered across the lake and there’s a few planes in the sky.
Geoff: The real question is can we let life go on as people want it and out of the same time preserve Tahoe actually do more to bring it back to what it may have been 40 or 50 years ago.
Ezra: Geoff leads the Tahoe Environmental Research Center through UC Davis.
Geoff: So what we've already seen in our data is the effect of climate change is effectively making the summers longer, the winters are getting shorter.
Ezra: Here’s what impact longer summers have. When its hotter, it’s tough for the warm water at the surface to mix with the cool water below. It also gets less windy … and we need wind to help mix the lake. Geoff says this turns Tahoe into a fish bowl… just sitting there, getting murkier and growing algae on its walls.
Geoff: It's a different lake. Is that a better lake? I don’t know. Bass fisherman like these lakes that are green and full of algae and full of fat fish. It depends on what you want but it isn't Lake Tahoe as people associate with in their mind.
Ezra: Also, this process of the lake becoming a different ecosystem indicates that climate change is accelerating, and as Simon with NASA points out: as Tahoe goes, so goes the rest of the world. Geoff says he's not sure how long it would take for this process to happen, or if Lake Tahoe would even turn green. He says it hinges on how we take care of it. I brought my friend Charley Pickrell with me to this interview and he asked a question.
Charlie: What are things that you think that we could do or maybe that you would do yourself so that when we do visit that we're having less of an impact on the quality of the lake itself?
Geoff: It starts with how you're getting here and I wish there were better options on how to get here. But there aren’t. You’re more or less obligated to have a have a vehicle. And that creates a lot of congestion. It also creates a lot of pollutant input to the lake. So the fact that you're standing in traffic for an hour in the middle of summer even if you're lucky enough to have a view of the lake you're not helping it by just idling there.
[water lapping ends and music fades in]
Ezra: What Geoff’s alluding to is there’s no real solution to protect this place from too many cars. More than 70 percent of the particulates that cloud Lake Tahoe come from urban areas and roads. There are 50 million vehicle trips to Tahoe yearly and no train or easy public transit to or around the lake. The region can’t wait much longer to come up with solutions otherwise it’s famous blue hue is in jeopardy.
[music plays then fades out under Ezra]
Ezra: OK so the clarity of Lake Tahoe is a big deal. But why does it matter? Throughout the podcast, we’ll have Emily Zentner on and she’s a digital producer and data reporter at the station.
Ezra: Hey, Emily...
Emily: Hey Ezra.
[music comes to end]
Ezra: So Emily, why does Tahoe’s bright, blue, clear water actually matter?
Emily: So we’ve talked with a lot of scientists about this and what they all mentioned is that same thing. It’s about the moment when you drive and you hit the top of the Sierra Nevadas and you see Lake Tahoe for the first time. And there’s this kind of emotional, and cosmetic and cultural connection that people have to that blue water that has these scientists studying this place in the first place.
Ezra: Yeah, that’s why I’m even doing this podcast. You know, my love affair began with Tahoe when I was a little kid. My grandparents lived in Reno and then Carson City and we’d come to Tahoe from the east side, we’d go desert landscape, through the pine trees, and then see this beautiful lake.
I have this one particular memory that always sticks out when I think about Tahoe. My dad rented a boat and he brought all of us kids out onto the water and none of us wanted to get in. We had just learned about sturgeons, these big fish in the water. And I looked over the side and I was like, “I’m not going in there.” But he threw my brother in and then I had to jump in. And you know, we realized, it was totally worth it to get in that water. You could see your feet, and I loved it. I understand you have some memories with Tahoe too.
Emily: Yeah, well, I am really glad that you did not get eaten by a sturgeon and that we are here doing this.
Emily: So, I actually grew up in a really really tiny town along Interstate 80 and when I moved away to college and people would ask where I was from, nobody knew the name of the town. So I would just tell them that it was the last Starbucks before you hit the Tahoe area and they instantly knew what I was talking about. So we spent a lot of vacations up in Tahoe. And I can just remember being a little kid, sitting in the backseat, and as we were driving down the highway we’d see the trees break, and just see this beautiful blue lake through all those pine trees.
Ezra: Yea, it reminds me every time of that first time you see the ocean.
Emily: Yeah, absolutely. You just see that water and you know you’ve reached Tahoe. So, I was a super nerdy kid which I’m sure is very obvious from what I’m here to talk about. And, my friends and I were fascinated with the crawdads that you could see in the lake. They have these giants claws and all these creepy feelers and they were just kind of scurrying around in there. And we totally did not understand that you can’t take things that are in the water, out of the water for extended periods of time without killing them. So we wanted these crawdads as pets and we would put them in buckets and carry them back to camp and we would just have buckets full of dead crawdads. And I feel terrible about it and that is a warning to future junior lake scientists. You cannot take things out of the lake without killing them.
Ezra: Yeah, I didn’t understand that either as a kid. I would collect tons of tadpoles, and frogs, and snakes. But, lets go back to data! Are we actually losing that iconic Tahoe clarity?
Emily: The lake is losing clarity for sure. And it’s hard to notice year to year sometimes because as the weather changes, the clarity changes too. But there’s definitely been that significant downward trend and the lake is getting less clear.
Ezra: But how do we actually know this? Is there a certain way that we measure this clarity?
Emily: So, when I was imagining how we would get this data and how they were measuring it. I saw a lab, I saw test tubes filled with this dirty water filled with algae. And what they’re actually doing is they basically have a white dinner plate tied to a rope and they lower it into the lake. And however deep into the lake that plate can go and they can still see it. That’s called the lake’s ‘Secchi depth’ and that’s the official clarity measurement.
Ezra: What is the Secchi Depth all about? Where does that name come from?
Emily: Yeah, so, Secchi Depth is actually a system developed hundreds of years ago for the Vatican and it was developed by a Jesuit priest. Which is where the secchi name comes from, his name was Father Angelo Secchi. And it was developed to be used in war, not to be measuring the clarity of this blue lake in California. And they would take the Secchi Depth measurements in harbors, and then that was how they made sure their naval ships wouldn’t hit the bottom of the harbor when they were pulling them in.
Ezra: Interesting. So it’s 2019 now, how is the lake’s clarity doing today?
Emily: So, Geoff Schladow’s group with UC Davis has been measuring Tahoe’s Secchi depth for more than half a century, and it’s definitely changed. In 1968, you could see more than 100 feet down into the lake. It hasn’t been anywhere near that clear since the late 1970s. Over the past 3 to 4 years, it’s been at about 70 feet, give or take, in the lake and it hit a historic low point of 60 feet in 2017. One of the researchers on Geoff’s team, Brant Allen, told me that that 1968 reading of about 100 feet is where he’d like to see the lake today.
Ezra: That would be a really big jump for us to get back to there. It doesn’t sound like that’s realistic.
Emily: It’d be a huge feat. I mean when you think about it, it was a different Tahoe in 1968. We’ve had a lot of things change. We have more tourism, there’s a lot more cars, and construction, and we’ve even added a species to the lake that’s making it less clear now.
Ezra: So it sounds like this idea of actually having a clear lake could be a pipe dream?
[music fades in]
Emily: Yeah, I think people want to come to Tahoe because we have this unique ecosystem, we have this beautiful clear blue lake, but by having all these visitors and combining that with the change in climate, we’re transforming that ecosystem and it’d be a really big challenge to get back to that.
Ezra: Well, Emily, thank you so much for joining me today. And crushing all of my dreams about this place I love.
Emily: Yeah, well I’m just here to be a killjoy.
Ezra: We’ll talk to you next time.
Emily: Thanks, Ezra.
Ezra: So NASA’s measuring how Lake Tahoe is changing from both the water and from space. And others are measuring clarity. The lake is surrounded by thousands of miles of forest. And within the Sierra Nevada as a whole, there are around 14,000 little lakes and ponds all going through similar experiences as Lake Tahoe.
[frog sounds fade in]
Ezra: Adrianne Smits and Steve Sadro with UC Davis are working on creating a historical record for these less famous bodies of water.
Adrianne: We’re going to do some sampling at Miller Lake.
Steve: This is one of our most accessible sites.
Steve: So you got off easy.
[ambi of stream and frogs]
Ezra: Miller Lake is west of Tahoe near Desolation Wilderness. I backpacked in Desolation last year and it was a perfect weekend trip. This spring was very wet with the fourth largest snowpack on record. A stream ran down the trail, we walked across huge patches of snow and had to cross at least one knee deep stream.
[sound of them crossing a stream]
Ezra: So what do you think? We’re gonna take our shoes off?
Adrianne: I’m not.
Ezra: You’re not, you’re just going to go?
Adrianne: Less chance of slipping.
Ezra: Adrianne walked straight across the stream, but Steve and I crawled across a log.
[frog and stream sounds continue]
Ezra: Well that was a fun stream crossing.
Steve: Even with that. Crossing with water below your knees it can be hazardous.
Ezra: Adrianne and Steve’s work is similar to NASA’s. They’re measuring these lakes to develop models to predict how all the other lakes in the world are responding to climate change.
Steve: It's important in a global context because there are mountains on all the major continents and the storage capacity of those mountains globally for water and the importance of those systems for water quality everywhere is really important and so we have the ability here to learn something really valuable that's going to inform ecosystem processes all over the world.
Ezra: When we got there Miller Lake was half frozen over. Still Adrianne and I paddled a blow up kayak into the middle of it to take samples.
Ezra: That’s really cold.
Adrianne: Sorry, I’m actually torturing you.
Ezra: You are torturing me. AHHH!
Adrianne: I can do it with two hands if you want?
Ezra: No, I can’t be that much of a wimp… Yes, I can though.
Ezra: We’re holding clear plastic tubes filled with air under the surface of the water and shaking them.
Adrianne: You’ll wanna make sure you’re agitating it enough. So, what we want to do is we want any C02 that’s mixed into the water to equilibrate with to what’s in the air.
Ezra: Addrianne leads a back-packing crew to 16 lakes every year stretching from Shasta to Sequoia National Park.
Ezra: Is the thought that these ecosystems are going to change?
Steve: Yeah. These ecosystems are going to change. The extent to which they're going to change is really going to be dependent on what happens to snow.
Ezra: We're gonna have a whole episode about how snow is changing later. But what Steve and Adrianne are trying to accomplish isn’t just about samples and data. People have emotional attachments to these lakes.
Steve: And so understanding how these areas might change as a result of climate is a big motivation for us. They're important to people who come to these spots sometimes to the same exact lake every summer. People feel a spiritual connection or some kind of natural connection to these places because they are wildernesses.
[frog sounds begin to fade out]
Ezra: Think of your favorite lake. Mine is Shaver Lake, east of Fresno, where I’m from. I caught my first fish there as a kid, in high school I had a mad crush on a counselor at a Christian Camp there.
[Hair In the Wind theme music fades in]
Ezra: And as an adult, hung out at the hot springs closeby with my best friends. It’s like the lake’s watched me grow up.
Ezra: So that’s the whole point. There’s this passion for Tahoe that’s fueling innovation. We’ll explore more of that in our next episode when we talk about research scientists facing off against a whole host of invasive species in the lake. And some of these scientists think they’re winning.
Geoff: It got clearer and it got clearer by an amount that was jaw dropping.
Ezra: Again, that’s in the next episode. But don’t forget about the bodies at the bottom of the lake. We’re going to unlock that mystery after the credits.
TahoeLand is edited by Nick Miller. Sally Schilling is our podcast producer.
Our Digital Editor is Chris Hagan. Emily Zentner is Tahoeland’s data reporter, Kacey Sycamore is collecting your questions about Tahoe, and answering them. Our website is built by Renee Thompson, Veronika Nagy, and Katy Kidwell. Linnea Edmeier is the executive editor. Joe Barr is our Chief Content Officer. And our associate producer is Gabriela Fernandez.
Our music is by artist Charlesthefirst. He’s from Tahoe.
To make sure you don’t miss any episodes, subscribe on Apple Podcasts or wherever you listen. Check out our website capradio.org/tahoeland for videos, photos, additional stories and more.
I’m Ezra David Romero. Thanks for listening to Tahoeland. From Capital Public Radio.
[Theme song comes to end]
Gabriela: Hey everyone! I’m Gabriela Fernandez, Associate Podcast Producer for Tahoeland. While reporting this podcast, we heard a lot of myths and urban legends. So we decided it would be fun to end each episode with a mini investigation. One of the things we heard a lot of was that there were a lot of these perfectly preserved dead bodies in Lake Tahoe. So we asked Tahoe local, Helen Filmore and scientist Geoff Schladow.
Helen: People say there’s old native americans, old Washoe people in the lake. The other one is the mafia. During prohibition times, Lake Tahoe was a popular spot for celebrities. So they say that it was a dumping ground.
Brant: I am sure there are dead bodies in the lake. But they’re in skeletal form.
David: One of the first legends I heard when I moved to Lake Tahoe in the 70s, that there was this rouge gallery of bodies.
Gabriela: That last voice was Dave Antonucci. He’s the Tahoe historian, you heard from earlier. He told me another piece to the rumor, apparently French explorer Jacques Cousteau dove to the bottom of Lake Tahoe and when he came out of the water, he said, the world wasn’t ready to see what was down there. It’s a bit of an eerie story if you ask me, but did that really happen?
David: None of that’s true. Jacques Cousteau has never been to Lake Tahoe. But his son Philippe Cousteau was at Lake Tahoe in 1975.
Gabriela: Plus Dave says the idea that dead bodies could be preserved at the bottom of the lake, isn’t even backed up by science.
David: The water of Lake Tahoe is alive with microorganisms and larger organisms that feed on dead plant and animal matter. So overtime, what happens is the body decomposes as it normally would and all your left with is fillings, body piercings, and joint replacements.
Gabriela: Alright, there it is. The legend of these perfectly preserved dead bodies has officially been debunked. I’m Gabriela Fernandez, next time we uncover the myth of Tahoe Tessie.
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