Welcome to Down to Earth, an audio podcast about the news, events and personalities that make up Earthjustice.

[Audio transcript:]

Jessica Knoblauch: So first of all, when did you start working at the Glacier Field Station and what kinds of changes have you seen in Glacier National Park since you first arrived on the job?

Dan Fagre: Alright. Well, I was hired to start the climate change research program here in 1991. One of the first things that we did was we went up and looked at Grinnell Glacier and we had written a proposal to use the glaciers of Glacier National Park to monitor the impacts of climate change through time. And so, I've sort of had an intimate relationship with that glacier in particular, but now most of them as well. And I've seen just without pulling out photographs or maps each year the changes that occur there. Now when we go up to monitor the size of the glacier on an annual basis we walk across rocks and land that has not been exposed to the atmosphere for probably 500 years because the glacier is retreating. So, in a sense, we're kind of the first people to walk on that in many hundreds of years since it was covered by ice.

So you do kind of have a sense of a personal relationship with the glacier as you watch it shrink and get smaller. So, it's still a pretty massive chunk of ice from a human perspective, but from a global perspective when you look at massive ice sheets and ice caps elsewhere around the world, it's really quite a tiny little shard of ice that's left.

Jessica: As you mentioned, a lot of focus has been on the glaciers melting in this area, but how does that affect the larger ecosystem? Is there an issue with water supplies being affected, for example?

Dan: Yes. I mean, we use glaciers in part as a barometer of the kinds of changes that are occurring throughout the ecosystem. It's easier to see the changes in the ice, but they basically represent the kinds of changes occurring to, say, soil moisture patterns, the timing of when stream flow begins in the spring, late turnover, a whole host of ecological processes. So the first way that we relate glaciers to the ecosystem is through just having glaciers act as a proxy for ecosystem change. For instance, most of our water actually comes from snow pack. Our glaciers are so small that they don't really contribute that much to the annual snow melts and water supplies that people downstream are dependent on and that our fisheries are dependent on. But, snow packs vary more from year to year. This year, for instance, we're having a very healthy snow pack and a few years ago we had a very small one. Whereas glaciers are more of a steady indicator because they integrate fluctuations in snow over time. And so that makes it a more reliable indicator of long term trends.

So if a glacier is retreating or it's advancing, either one, it indicates trends over many, many years, not just year-to-year annual variation. So that gives us a good measure of the long-term change. The other way though is that glaciers do provide a direct impact to especially aquatic ecosystems because when most of our snow packs are gone by late July and August if you come here and hike the upper elevations are actually barren of most snow and what you see left are the glaciers.

The melting of those provides critical water supply to our streams in the upper elevations particularly, and that is where many of our fairly unique alpine aquatic biota live. So they not only need the water, it has to be very, very cold water because they're alpine-adapted species. The glaciers kind of provide a buffer, a reserve, a lifeline, whatever term you want to use, but without them there those streams would either be too warm or would dry up entirely. The glaciers are acting as kind of a critical buffer against late summer heat for a lot of these species. So when the glaciers are gone there will be a distinct change in at least some alpine biota.

Jessica: It sounds like the warming of the climate is having a negative effect on some species, but are there any examples of a warmer climate actually benefitting other species, and how is that changing the ecology of the area?

Dan: Oh certainly. When a climate warms, there are winners and losers because species are adapted to the ecosystem and the climate regime over long periods of time. And so when that changes and in particular when it changes quickly, there are going to be, you know the old saying about nature, it abhors a vacuum. There's going to be something that enjoys the new, warmer climate. So, we may have more lodge pole pine, for instance, and fewer hemlock and cedar forests. Certainly, we may have more insect outbreaks, but for instance when we have more fires it benefits cavity-nesting birds because then they have more places to nest and so forth. Certainly we have had changes in the aquatic biota as the streams warm up, certain fish and in some cases invasive fish species that aren't native to the area do better than the native species that are adapted to the colder waters.

Similarly with our alpine charismatic species, there's been lots of questions about how pika will be able to respond to warmer temperatures and there's been some speculation about mountain goats and so forth. But it's very likely that certainly our mule deer and white-tailed deer will do better in the new environments that we create. Anecdotally we've been seeing more raccoons and foxes in Glacier National Park then have been recorded in the past. So they seem to be finding the warming climate and the responses of the ecosystem to their advantage. So yes, you are absolutely right. There are going to be species that benefit from climate change locally.

Jessica: That Newsweek article that you were interviewed for ["The Case of the Disappearing Rabbit"] mentioned the snowshoe hare and how fewer of those have resulted in lynx having trouble finding food as well as other animals that eat the snowshoe hare.

Dan: Yeah, that's exactly right. When anything affects one species, you're going to have a cascading effect on others. And so, as a prey species either increases in abundance or decreases in abundance, obviously there are predators directly linked to that. Some predators are flexible enough to find other prey and others are more directly linked because of their adaptations to a certain prey base. The lynx is an example where it has a big advantage in the snow with its huge paws, and so it's what is often called a snow-dependent carnivore. Many of its adaptations are not really an advantage unless you've got that snow. So other predators can out-compete them, like coyotes could move in because they can do pretty well in snow but not quite as well as lynx, for instance.

And similarly, species like the wolverine are quite dependent on snow pack for denning, in particular, although they have lots of other adaptations to cold weather and snow that give them an advantage over other smaller carnivores. So when you have snow packs as we've had here declining in both the total amount in their water content, or snow water equivalent as we call it, or the duration, the snow pack's melt weeks to a month earlier, they often don't get started and accumulating until later in the year. So there's less snow on the ground on an annual basis than there used to be and there's less of it. These are obviously not going to bode well for snow-dependent carnivores.

Jessica: And like you said, the wolverine is having trouble with less snow being on the ground and actually the wolverine is already a threatened species. Are there other examples of species that are already threatened, not just by climate change but that have low populations in general?

Dan: We often think of climate change as one of a stress complex. You have multiple stressors. And so, for instance, species that need a lot of room to roam are more vulnerable because as they have more landscape development around places like the park or wilderness areas where some of these species do well, it's harder to cross over developed land that's been fragmented by roads and factories and farm land and so forth. And then if you add climate change on top of that, the two stresses might do to that population what one didn't.

In other words, it's sort of like an immune system. You can handle a certain amount of germs and everything on a daily basis, but once you get run down, all of a sudden you get sick because your immune system has dropped. Well, in a parallel way, that's what seems to be happening for many parts of the West at least where something like air pollution and landscape fragmentation doesn't have a big effect, but then something like climate change can be the one that puts it over the top, that's basically a tipping point. So in those cases, it's often a focus of managers to be looking at one threat or one stress on a species, like our bull trout, for instance, and some other stressor comes from behind in the background that they're not really thinking about and actually provides the final little push to create a situation where that species is now suddenly very vulnerable.

Jessica: So it adds more stress onto an already-stressed animal essentially?

Dan: Yes, it does. Certainly for some of them. As we said earlier in the conversation, there are some that are going to benefit from this and so it would actually reduce any stress that they might have. But the issue is, which species? Certainly one of the goals of much of our conservation and our landscape protection strategies is targeted to keep certain species. And in many cases those are ones that are going to be made more vulnerable by climate change.

Jessica: You've mentioned in previous interviews that the effects of warming are magnified by two to three times in the Crown ecosystem, which Glacier National Park is a part of. Can you explain a little bit about what you meant by that?

Dan: Certainly. What we've done is a historical analysis of climate data for western Montana with a focus on the Crown of the Continent area, which Glacier National Park is part of. And simply by looking at what warming has already occurred in our area, it has been two to three times the global average. Particularly with respect to extreme values. In other words, we looked at how quickly the number of days over 90 degrees Fahrenheit occurred in our area versus other areas. And we found that we had many, many more of them, two to three times in fact.

We chose that 90 degrees because it's a threshold for physiological stress for lots of plants and animals. Plants will start conserving water, close up their stomata and so forth. Animals will go into shaded areas or underground to get rid of the heat. For many alpine and mountain species that have adaptations for extreme cold, well that works great as long as it's cold but once it gets warm, once you start getting these days over 90, it's like they can't take off an overcoat. They can't go inside and turn on the air conditioning, so they do experience some stress in many cases if they can't change their behavior.

So we wanted to particularly look at how much more our environment might be stressing them. It turns out that we are quite ahead of the global average. But this is not unique to our area, per se. Many mountain areas over the globe have warmed up faster than lowland areas so it’s a little bit more of a problem like in the Arctic and Antarctic where warming has occurred faster than the global average as well.

Jessica: The Crown is such a big expanse of land, it has a lot of microclimates. How is that affecting how it's responding to climate change? Are there certain areas within the Crown ecosystem that are more affected than other areas?

Dan: Yes, I think our highest elevations are probably being affected relatively more than the lower valley locations, for instance. Because snow melt is such a key trigger for lots of ecosystem processes, when that occurs earlier in the year and the timing of that changes it really affects a lot of those organisms a lot. An example is that we have a relatively rare alpine poppy, a small flower that mostly grows beneath snow banks and glaciers and is dependent on the moisture from that. And if the snow melt occurs earlier in the year and it warms up to much, first of all the timing of the growth is not keyed to the season like seasonal light and other things like it used to be. Secondly, it may run out of moisture before it completes its lifecycle for the year. And so, those kinds of timing issues, basically the phenology as they call it, of growth and so forth, that's as critical as how much change there is.

So there's kind of two dimensions of how climate change affects things: when it happens on a seasonal basis and so forth and then how much it warms. So, sometimes just a shift in when it's occurring can have just as much ecological effect as the total magnitude of the warming. So, a 90 degree day in August is not going to cause as much stress to these organisms as a 90 degree day in May because it's the wrong time of year for that heat to be there and it basically messes up with their rhythms. So that's something else that we need to keep in mind when we look at climate change effects on mountain ecosystems.

Jessica: What about snow avalanches? Has a changing climate affected those at all, are we getting more or less?

Dan: Well, we don't know. We are speculating that we will have some significant changes in our snow avalanche dynamics. Basically, it's what's occurring right now in many mountain areas. That is typically what you have is what we call dry slab avalanches in the winter. These are deep snowpack so that the snow is cold and so forth. You get unstable layers deep in the snowpack so when the avalanche goes it all slides as one big unit and its dry breaks up. It's a particular kind of avalanche. And that's important for keeping some of these snow corridors open continuously so forests don't invade. That eventually winds up being important for species like grizzly bears and others that forage in these avalanche paths where the trees are continually scoured out and you have much more nutritious vegetation growing in those paths. So there is a complicated link between how much snow we get, what kind of snow it is, landscape features like snow avalanche paths and basically the ecology of birds, bees and bears.

That's one aspect of it. The issue is that as we move to warmer climates, as we have in the last 50 years and particularly in the last 20 years, we're seeing unusual things that are big snow storms followed by rain, for instance. And you have a rain on snow event and it destabilizes snow in a different way. And it causes many of these areas to slide in the winter in a wet form that's unusual. And we look at this as a trend, but if it continues we're going to be having our snow avalanches and our rain events, for instance, in some cases cause flooding in January or February, which is really seasonally very wrong. In other words, it's just not what this ecosystem is adapted to. And the character of those also changes through time. You might get more entrainment of dirt, soil, boulders and debris with these wet avalanches that are increasing in magnitude. And, as they dump all of that in streams, then you start changing the nutrient quality of those streams and the turbidity and all these other kinds of things.

So as a disturbance phenomenon, any time you change what it is and when it occurs, the rest of the ecosystem has to adapt. So we are exploring this. We don't really know all the ways in which this will occur. It's an area that has had relatively low research and we have started some programs but we real definitive results yet. But clearly, one thing that we can say is that throughout the Pacific Northwest, the average snow line has been going up. There have been more rain on snow events and warm, actually subtropical systems coming in and changing our snow pack, making it warmer. For instance, it melts earlier in the spring. And ultimately because we already have fewer days of snow on the ground, we may have fewer snow avalanches in the future. We don't have enough trend information to say that now, but it's a reasonable speculation based on the information that we do have. And if that occurs, we may have a different looking landscape that hasn't had the benefit of this regular disturbance to keep these areas open and make them valuable wildlife habitat.

Jessica: Well, and it sounds like we've went past the point of mitigation onto adaptation because we're already seeing on-the-ground effects of climate change.

Dan: I think that the scientific consensus is that we are already committed to a certain amount warming and that adaptation is of course the smart thing we should be doing. One of the roles that the USGS plays is to try to figure out what you need to adapt too. We continue to do what's called climate impacts research, which is basically not only documenting what's already happened in the warming that's already occurred and the changes we've already seen, but also trying to figure out what monitoring we need to do for the future and what information managers are going to need in the future because in many cases you need to have five, 10, 20 years of data to really be able to know what's going on and make management decisions.

A case in point is the pika. The pika is a low rock rabbit, cute little organism that lives up in the high alpine areas and when the concerns about it first surfaced we didn't have any population data. We knew their biology and so forth, but we didn't know how many we had and where. So you couldn't really see any trends because you had no population data. And that's a case in point where a much better evaluation could have been made if those data had been collected, but because it wasn't a concern in the past nobody had thought to do that. So one of the responsibilities that we as scientists have is to try to figure out what should we be looking at and monitoring now because this information will be needed in the future.

Jessica: And so basically in those cases you just want to establish a baseline in order to find out what has changed since that baseline?

Dan: Absolutely. But unfortunately, nobody on the planet can afford to get baseline data on everything so you have to choose some representative phenomena, like monitoring snow pack in streams and some organisms. And that's what a lot of work is being devoted to now is trying to get information on what we can. Luckily one of the advantages that we have with trees is that they're very long lived and that they record climate information. And so there's been quite a lot of interest in using trees as basically climate history books to look back in time and see what kinds of patterns there have been in the past and also see how the ecosystem adapted to those.

And so these sort of analogs are useful for looking at the future. And we can see where, in this area for instance, we've had huge mega droughts, periods of 20 to 30 years of drought going back to the 1600s. That's really kind of a wake-up call because we tend to look at the variability we've experienced in our lifetimes, for instance. It's just a natural human thing to think that what you've experienced is the long-term norm. The advantage of trees is that they say, nope, this area has experienced some really long and severe droughts in the past and we haven't experienced any for quite some time. So if you look at the patterns you could almost say we're "overdue." But we also know that there have been some times where it's been warmer than the long-term average, there have been times it's been cooler. We can look at those periods and see what kinds of changes occurred.

An example, for instance, is that in the 1500s and 1600s when we were in the beginnings of the so-called Little Ice Age, a lot of our cedar and hemlock trees established then because it was cooler and wetter. Now, when it's warmer and dryer, these trees are still persisting, but they probably couldn't get started here now. In other words, the climate envelope for them has changed, has moved on. And yet they persist here simply because they're long-lived organisms. So when we have a major forest fire and it happens to wipe out those trees, we probably won't get them back because the climate is no longer suited for them. And those are the kinds of things you can see how the ecosystem is responding over long time periods and get a much better sense of how it will probably respond in the future. There are a lot of lessons from the past that are germane to looking in the future when you consider a mountain ecosystem like what Glacier National Park encompasses.