Life on a Melting Planet
“Earth is warming!” “Glaciers are melting!” “The level of the ocean is rising!” We have all read these headlines, and yet, what do they mean for us? It was a hot summer, but how hot is too hot? Few people live where there are glaciers, so how many glaciers can there be? Even for those of us who live near the ocean, what’s a few centimeters? Won’t that be like a really high tide? I am being facetious with these questions, but even for someone who understands the science of climate change as well as I do, the immediacy of the headlines did not feel pertinent to my life.
That changed on a recent trip to Peru. Thirteen months ago, family friends called to talk about the hike into Machu Picchu my husband, son, and I took in 2012. Strenuous hiking in remote areas is one of my husband’s and my favorite ways to vacation. This hike, called the Salkantay Trail, through mountainous terrain at altitudes spanning from about 7,000 feet to over 15,000 feet above sea level (the average is over 12,000 feet) is our kind of hike. So, when our friends decided to go, we went with them.
We traveled to Cusco (altitude 11,152 feet) a week before the hike to acclimate. Global warming and climate change were not on my mind for that first week. Catching my breath was! On day five in Cusco, I could climb the stairs built into the hillsides throughout the city, with only a few stops. By day seven, I was ready to hike the Salkantay trail.
Salkantay Trek: Days 1 & 2
The trailhead is a three-hour drive from Cusco. There was a traffic stop along the way for a large highway project where they were fixing damage from a landslide. I did not know it then, but damaged roads and trails were to become a common theme over the next week. Another common occurrence would be bridges that were either washed away or submerged.
Once we arrived at the trailhead, we hiked about 6 miles to our lodging. As I hiked, I noticed there was quite a bit of water flowing from the peaks. I didn’t think much about it at the time. I also didn’t make any connection when I learned about the landslide that had damaged part of the road where we walked 12 years earlier. For that reason, we used a different trail. On day two, we took a day hike to Humantay Lake. Humantay Lake is a glacier fed lake at an elevation of 13780 feet. Once again, we took a different path to it. This time, because of the amount of water flowing down the mountain.
Humantay Lake in 2023. It is a glacier-fed lake at 14,300 feet of elevation. What will happen to glacier-fed lakes and the surrounding ecosystems when the glaciers have all melted? It is going to happen. We should be working on those solutions now.
Salkantay Trek: Day 3
Days three and six are the most strenuous days of the six-day hike. The hike on day 3 is over nine miles long over Salkantay Pass at an elevation of 15,190 feet. Between the distance and the slow hiking speed (the elevation really slows you down if you are not used to that altitude), there is a lot of time to think.
I realized that there was water running down the mountain everywhere we had hiked over the first three days. It was running down the mountain in streams and rivers and making swampy areas in fields. Both times we hiked on the shoulder of the rainy season, so water was to be expected, and I understand that the weather for two years will not be the same. As I made observations, it felt like more than just differences in the weather.
At first, as we neared the top of the pass, I didn’t even realize how close we were. In 2012, there was snow on the ground and glaciers in the peaks, creating glacier-fed lakes. The lakes were still there, but the snow was not, and the glaciers were much smaller. I concluded that the source of the water running downhill to lower elevations was melting glaciers and snow.
2012 at the summit.
2023: It isn't very noticable from this photo, but there was much more snow in 2012
2012 at the summit: another glacier-fed lake
2023: The same lake from a different angle. As you can see, all the snow is melted.
Just after we reached the top, there was a landslide accompanied by an avalanche. We had been hearing what sounded kind of like thunder, but kind of not too, off and on for about thirty minutes, when the large slide took place. We could see snow spraying up along with the rockslide. It is awe-inspiring and scary to be that near to. There was so much rock and snow, and it was loud when it slid. It also went on for several minutes.
As the slide occurred, I started connecting the changes we observed to the effects of global warming and climate change. Glaciers erode mountains. Glaciers contain huge boulders. Intact glaciers function like cement. When they melt, the rocks and sediments they contain are released causing landslides.
As we descended on the other side of the pass, we saw the evidence of a slide that happened on February 23, 2020. This was the second large landslide caused by glacier collapse to happen in the area that month. On February 23, a glacier carrying the rocks contained within it collapsed into a lake. This displaced a huge amount of water. The water and debris from the glaciers triggered an enormous debris flow causing mudslides and flooding miles and miles away. People were swept away and killed, buildings were destroyed, the course of rivers were changed, and bridges washed away.
Huge boulders were strewn across an area where we picnicked eleven years before. There would be no picnicking now. In 2020, the slide happened when people had been picnicking in the same spot. They were killed during the landslide. Our guide kept us together and got us through this area.
The Glaciers of Peru
If you were asked to list five countries with glaciers in them, Peru would probably not make the list. It sits just below the equator, after all. That ignores that one quarter of Peru is mountainous. Glaciers do not just form at and near the Poles at high latitudes. They also form at high altitudes like those found in the Andes Mountain range.
The Andes Mountain range spans 1.301 million square miles. For comparative purpose, the United States is less than three times the area of the Andes at 3.8 million square miles. The largest state, Alaska, is 6.7 hundred thousand square miles. The Peruvian Andes are home to seventy percent of the world’s tropical glaciers. A tropical glacier is a permanent ice mass located within the tropics, typically between 10° north and south of the equator. Despite the hot and humid climate, these glaciers exist at high altitudes, where temperatures are low enough for ice to accumulate and persist. Tropical glaciers play a crucial role in the environment. They provide a vital source of freshwater for organisms including millions of people in the tropics, especially during dry seasons. Their meltwater sustains rivers, wetlands, and forests, supporting diverse plant and animal life. They act as sensitive indicators of climate change, highlighting the impact of rising temperatures on global ice reserves.
People who study the effects of global warming have been documenting the loss of glaciers for many years. This link takes you to a video explaining about glacier loss in the Bolivian Andes. The video is ten years old, and states that there had been a 43% loss by area of glaciers. In November 2023, the National Institute of Research on Mountain Glaciers and Ecosystems announced that Peru has seen a 56% decrease in its glacier area over sixty years. The loss has accelerated over more recent decades as Earth has gotten warmer.
This timelapse video from NASA shows melting glaciers in the mountains of Tibet. Glaciers are melting in all mountainous regions across the globe. This is having a major effect on these ecosystems.
Salkantay Trek: Days 4 through 6
We would hike over 26 miles during the following three days. We walked along the path of the debris flow from the landslide in 2020 throughout this distance. During this time, I thought a lot about what I was seeing. I also thought about the way people compartmentalize events based on things like “the human toll.” But what about the majority of landslides? Those that do not fall into lakes and trigger large debris flows. They are still occurring as glaciers melt. The amount of water flowing downhill coupled with collapsing glaciers indicates these glaciers systems are starting to fail.
Days four and five took us through a cloud forest. I had to wonder what will happen to this ecosystem when the glaciers melt. Every river was flowing hard. Many were brown with sediments and nutrients. We saw several bridges that were washed away or submerged. In rivers, streams, and across flat areas, there was water everywhere!
We took a different path on Day 5, because the bridge we were supposed to cross was partially submerged.
The rivers were flowing to the Amazon River and then into the Atlantic Ocean. This is something most of us learned in elementary school. But I want to pause, so you can think about what is happening. Global temperatures are increasing. For that reason, glaciers are shrinking. They are not growing or staying the same size. Some glaciers “feed” lakes. Even those that do not feed lakes are a source of water where they are located. Their presence has a big impact on ecosystems. The Andes Mountain Range is on the west coast of South America. When glaciers in this mountain range melt, the water they contain is relocated to the Atlantic Ocean on the East Coast of South America. In addition to water, sediments and nutrients are also being transported to the Atlantic Ocean.
I found myself wondering, “what will happen to these mountainous areas when the glaciers melt?” Without these glaciers, these areas will be warmer and dryer. What will happen to the organisms that are adapted to the current climate conditions? Can they adapt to the new conditions? If not, they do not have anywhere to go. And what about the people who live and farm in this area? How will they survive? We are going to find out because the glaciers in the Andes Mountains are melting.
What We Can Do Is to Educate Our Children about this Science!
I do not think there is anything we can do to stop the glaciers from melting. We can’t stop the affected ecosystems from changing, either. Other than working to have a small carbon footprint, there is not much we can do to slow or stop global warming. This is the sort of thing that makes this issue seem hopeless. I get that.
If we take the Glaciers of Peru as a symbol for climate change, it is a compelling one for why we should all commit to teaching our children the science explaining the related topics of the greenhouse effect, global warming, and climate change. Because even if we cannot stop it, we are going to have to deal with the fallout, and understanding the science helps us identify the fallout areas before they reach emergency levels. Understanding where we are headed and why allows us to implement preventative measures to mitigate the impact of climate change, protecting communities and ecosystems from the worst consequences.
The world is melting. This is going to have a profound impact, not just on areas where there are tropical glaciers, but everywhere, including where you live. We need to arm our children with the knowledge that will help them negotiate and understand the changing world.
Check out The Science of Climate Change from Blair Lee, M.S.
“The Science of Climate Change: A Hands-On Course is an incredible resource for students and their teachers to learn about what causes climate change and what we can do in our everyday lives to solve this problem.” National Science Teachers Association.