Pro climber Tommy Caldwell details the impact of climate change on climbing : NPR

NPR’s Alina Selyukh chats with professional climber Tommy Caldwell about how global warming is changing the outdoor sport and making it even more dangerous.


Climbers watch their favorite mountains crumble due to climate change. While extreme heat and long-lasting drought affect everyone, they have a unique impact on the world of outdoor recreation. Tommy Caldwell is a professional climber who has climbed some of the toughest mountains in the world. He’s joining us from Colorado. Welcome.

TOMMY CALDWELL: Nice to be here.

SELYUKH: So with drier summers and warmer winters, what challenges do climbers face in the mountains?

CALDWELL: I mean, I think the most obvious example is probably melting glaciers in the mountains. Like, this is the most visually obvious. We go up into the mountains, and the glaciers recede. The mountains themselves often melt, which for ice climbers means less ice but also more rockfall. For example, those mountains that have always been frozen together are kind of melting and collapsing.

SELYUKH: That’s true. And earlier this summer we had this incident where several people died hiking in the Dolomites in Italy when a glacier broke free. For example, is that kind of an example of those possible disasters that you’re watching out there?

CALDWELL: Yeah, so that’s a pretty dramatic example. But, you know, in one of my favorite places to climb in the world, which is Patagonia in southern Argentina, we just started noticing that we get these really hot weather windows for weeks, this which really hasn’t been used be the case there. The weather was pretty bad. And so everyone is excited because the weather is good for climbing. If you are a climber, great. But every time there is a good weather window, someone dies. And so I stopped going. You know, as a father, this – these days, myself, I just decided it was too dangerous. It’s just – which is sad. You know, it was my favorite place to rock climb in the world.

SELYUKH: And what were the conditions that cause deaths in Patagonia?

CALDWELL: It’s just rockfall – increased rockfall. So when you are climbing these very large steep mountains, falling rocks are always one of the main dangers. But sporadic rockfalls that occur with really no warning have become common enough to become far more dangerous.

SELYUKH: And are these dramatic changes causing problems in places like Patagonia or maybe Yosemite, or are you thinking of more subtle changes as well?

CALDWELL: I mean, pretty dramatic. For example, the fact that I can’t climb in one of my favorite places in the world is dramatic, but there are also some relatively dramatic changes happening closer to home. For example, Yosemite is where I climb the most. And Yosemite Valley is going from kind of a dense pine forest to this kind of open oak forest pretty quickly. First because all the trees – most of the pines are dead because of insects. And then, more recently, fires have, you know, devastated the area, mostly around Yosemite – a bit in Yosemite as well. And so, yes, the landscape has changed dramatically. And we can’t climb there often in the summer because they just close the park because it’s too smoky or it’s too unhealthy to climb.

SELYUKH: You know, I hear climbers doing what we call the last peaks. What does that mean? Or sort of how do you think about this potential path in which we might no longer be able to enjoy certain mountains due to the impact of climate change?

CALDWELL: Yeah, so I first heard about this idea of, like, the latest climbs from Kitty Calhoun, who did a great TED talk maybe 10 years ago about these ice climbs who were disappearing. And she was going to climb them thinking that she was probably the last one who could climb them. It’s a thing. I mean, in Patagonia, another thing is some of these big, beautiful walls that I’ve wanted to climb – as the glaciers recede and melt, they tend to break up, and there’s a lot of crevasses. And they are sometimes almost inaccessible for a while.

I also went to the Arctic National Wildlife Refuge a few years ago, and the polar regions and the high altitude regions, the – like, the warming effect is in your face. It’s really obvious. And I had to do a lot of research ahead of time to figure out where we could go because those glaciers you usually walk on had melted. And now it’s just loose, somewhat gravelly, dangerous terrain to travel on.

SELYUKH: You know, are there any new opportunities opening up through all of this? Maybe places that used to be too cold for an adventure are now more available.

CALDWELL: Yes, there are places. Like, Yosemite is a great example of where you used to climb there – you know, the best season for free climbing, which is the type of climbing I like to do, was October and april. And now you can go out there and reliably climb El Capitan all winter long, as long as the smoke from the wildfires doesn’t get to you. So there are places that I climb where there are just these really long periods of heat that can be good for climbing.

SELYUKH: It’s professional climber Tommy Caldwell. Thank you very much for being here.

CALDWELL: Yes, thank you.

Copyright © 2022 NRP. All rights reserved. Visit the Terms of Use and Permissions pages of our website at for more information.

NPR transcripts are created in peak time by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative recording of NPR’s programming is the audio recording.