Video transcript
The video is 7 minutes and 32 seconds long.
Produced by the American Museum of Natural History, March 2005.
Speaker: Lonnie Thompson, Department of Geological Sciences, Ohio State University
Visual: Peruvian glaciers, glacial lakes with floating ice blocks
Our research looks at climate history of the planet, through what’s recorded in the layers in the ice and glaciers around the world. We’re documenting the change in the past and also the change in the 20th century.
Visual: Flowing water at the base of glacial walls, dripping water from icicles
What we’ve seen so far, and I think of what should really be of concern to humanity, is what’s happening to glaciers in places like right here in Peru, the tropical glaciers.
Visual: Melting ice
They’re all retreating. They’re retreating in Africa, they’re retreating in the Andes, they’re retreating in the Himalayas. In as little as 15 years, in some of these places, like on Kilimanjaro, there will be no archive. There will be no history left from the ice.
Visual: Busy Peruvian village, children, snow-capped mountains towering above village
We’ve worked in 15 countries, particularly in the very high elevation sites in the mountain regions around the world...
Visual: Scientific Expedition walking up the mountain on rocky terrain surrounded by ice and snow
And the reason that we go to very high elevation is that we want to be above where melting takes place.
Visual: Scientists pitch tents as the sun sets
We want to have a record of the annual snowfall preserved through the ice archive, the history that’s recorded in these glaciers.
Visual: Morning, expedition taking breakfast, Lonnie Thompson is introduced
Speaker: Lonnie Thompson
This’ll be my 20th trip to Quelccaya—the Quelccaya ice cap.
Visual: Loading packs on a horse, zoom into satellite data showing location of Quelccaya ice cap in the Andes of Peru, South American
The Quelccaya ice cap is 14 degrees south of the equator.
It’s in the easternmost section on the Andes, and from Quelccaya last year we drilled two cores to bedrock.
Visual: Dr. Thompson and others hike up the glacier
This year we only need one year to bring our 2003 ice core records up to 2004.
Visual: Dr. Thompson points to the lake forming at the base of a distant glacier
This is the Qori Kalis glacier that you see down in the valley here.
This is the largest outlet glacier coming from the Quelccaya ice cap, the Quelccaya ice cap being the largest tropical glacier on Earth.
Visual: Montage of photographs of the Qori Kalis glacier, from the same angle, over the years, showing the retreating glacier and the growing lake below it
And we’ve been studying this glacier since 1978, and since then we’ve been coming back and photographing, initially the retreat of the ice but then the formation of the lake that you see there.
And through time this retreat has accelerated, so recently we’ve been actually photographing this just about every year to get the change.
Visual: Dr. Thompson and others hike up the exposed mountain along the edge of a glacial lake
In 2001, we actually came up along this lake, and this was not exposed.
In 2002 while we were waiting for the horses, I decided to come up just to look at how fast new vegetation was occupying the new land being exposed by the retreating glacier, and I just happened to cross this plant deposit, and the date of the plant would tell us the last time this ice cap, Quelccaya ice cap, was smaller than today.
Visual: Dr. Thompson lifts up some largely decomposed but still recognizable plant matter from the ground near the edge of the ice
So we had it dated in two labs, and it dates 5,200 years ago.
So that tells us that this ice cap has not been smaller than today for 5,200 years.
Visual: Distant shots of hikers going up the glacier, camp at the summit
Speaker: Keith Mountain, Department of Geography and Geosciences, University of Louisville
Visual: Dr. Mountain is introduced
We are standing on the summit of the Quelccaya ice cap.
An elevation of 18,500 feet above sea level.
Visual: Dr. Mountain and another scientist use a hand-turned drill to dig a core out of the ice
We see here a 1,600-year record.
Each seasonal snowfall that occurs here that does not melt, preserves a little part of that history of that year.
So it lets us see back into the past.
Visual: The ice core is slid onto a carrying container
Visual: Sign: Scott Hall, Byrd Polar Research Center, The Ohio State University
Visual: Dr. Thompson in the ice core storage rooms, reviewing the cores on light tables, shelves of hundreds of cores
So one of the objectives here is to document that history, but also to archive some of that ice for the future, because we know that our technology, our understanding will continue to increase as we go into the future, but those archives aren’t going to be out in the natural world.
Visual: In the lab, the lab technician is working with ice samples, small pieces of ice with trapped air bubbles
One of the really unique things that the ice records is in the bubbles trapped in the ice, which is simply the atmosphere of the past.
There is a gas record of the composition of the Earth’s atmosphere.
Visual: Liquid samples in test tubes placed into a testing machine, shot of computer monitor showing the chemical analysis
So we can extract those bubbles, and those molecules that make up the water, that makes up the ice, and we can measure how the climate system has changed through time and particularly how’s it changing in the 21st century.
Visual: Dr. Thompson in his office, presenting a series of graphs on his monitor
This is the last thousand years of annual climate variability from the Quelccaya ice cap, and you can see things like the medieval warm period here in the early part, a little ice age, and the warming in the 20th century.
If we look at the ice core record, certainly in the last hundred years, the thing that stands out is the huge increases in concentrations in all these parameters in the last 20 years, and for sure, we as human beings are changing the composition of the atmosphere.
Visual: Dr. Thompson on the mountain along the edge of the melting glacier
I grew up in West Virginia, a coal-mining state, and always heard these stories about the canaries that the miners would take down, and when the canary died, they got out of the mine.
And to me the tropical glaciers are canaries, and they’re telling us the system is changing.
Visual: Back at the camp on the Quelccaya ice camp, tents, turning the drill to extract an ice core
This issue of climate change and global warming is a real issue.
We’re not talking about a belief system here. We’re talking about what is, and what can be documented by facts and by science, and that we need to look at this and adjust our policy, our way of living, our values, based on the idea of sustainability, and that we all need to live on this planet.
Visual: Herd of Alpaca in the fields at the base of the mountain