Download LAB 6B – Permafrost: A Soil with a Past and an Uncertain Future

EAR 203
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EAR 203 EARTH SYSTEM SCIENCE
SYRACUSE UNIVERSITY
LAB 6B – Permafrost: A Soil with a Past and an Uncertain Future
(adapted from http://serc.carleton.edu/eslabs/carbon/5b.html)
Introduction
Soil Profile. Courtesy Enrico Zimbres: Wikicommons
Do you ever think much about the soil under your feet when you walk to school? What is soil made
of? How does soil behave under different weather and climate conditions? What lives in soil?
Perhaps your family has a compost and you already know the importance of soil organisms in
creating rich, dark soil. Farmers certainly know the importance of good, rich soil in growing healthy,
robust crops. Understanding soil is also important to people who study the carbon cycle and
climate change. This is because soils store a lot of carbon! As a matter of fact, more carbon is
stored in the world's soils than is currently present in the atmosphere.
When we look at the soil beneath our feet, soil seems fairly simple to understand. Actually, soil is
one of the most complicated reservoirs of the carbon cycle. Scientists agree that there are many
unknowns about how soil might respond to climate change and that the following essential
question needs additional research:
What will happen to the vast amount of carbon stored in soils if the climate continues
to warm?
In this lab, you will use videos and readings to explore a very special soil with an interesting past and an uncertain future—the
permafrost.
By the end of this investigation, you will be able to:
 Describe the possible impact of a warming climate on permafrost
 Use systems thinking strategies to identify any feedbacks between a thawing permafrost and the carbon cycle.
Permafrost: A Soil with a Past and an Uncertain Future
Tundra. Courtesy: Billy Lindblom.
If you walk along the Siberian tundra, you have to watch where you
walk. You could fall into a thawing sinkhole, trip over a mammoth
skull, or even come upon a buried Iron Age tomb with bodies and
horses still frozen inside. This is the Siberian permafrost – a soil that
has been frozen for thousands of years. As the climate warms, the
permafrost is changing - it is beginning to thaw.
To learn about permafrost, log onto the following web site:
http://serc.carleton.edu/eslabs/carbon/5b.html
In the spaces provided below address the questions raised in the
Discussion Sections of the lab.
Lab 6B - Permafrost: A Soil with a Past and an Uncertain Future
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EAR 203
Discussion
 What evidence did you observe that permafrost is thawing?

What evidence did you observe that methane exists in large amounts in the permafrost?
Discussion
Permafrost. Credit: Ted Schuur.
Discussion
Consider the diagram of permafrost soil above, and make special note of
the active layer. This layer contains carbon from dead plants and animals
that have died within the past few years. The permafrost contains very old
carbon - perhaps hundreds to thousands of years old. When this
permafrost melts, the carbon is made available to microbes which then
produce carbon dioxide and methane.
Answer the following questions:

Describe how changes in the depth of the active layer of the freeze -thaw cycle could "unlock" some of the Arctic carbon in
this soil.

What role would microbes have in this process?
Lab 6B - Permafrost: A Soil with a Past and an Uncertain Future
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EAR 203
Stop and Think

Explain how a thawing permafrost creates ideal environments for methane-producing microbes (methanogens).

How might permafrost microbes impact the current greenhouse effect if the permafrost continues to thaw?
Tracking carbon in a warming tundra
Follow the work of two researchers who are tracking carbon in the warming Arctic tundra. As you view and read about the
researchers' work, think about the following:
 What are they doing to track the carbon in carbon dioxide( CO2)and methane (CH4) as the tundra warms?

What evidence do they find that would indicate that the release of CO 2and/or CH4 is being amplified?

Does their research "uncover" evidence for possible feedback mechanisms as the permafrost thaws?
Lab 6B - Permafrost: A Soil with a Past and an Uncertain Future
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Discussion
 Are a warming Arctic climate and a thawing Permafrost related to each other in a feedback loop? Use your notes to draw a
diagram of any potential feedback loops that might exist due to a warming Arctic climate. You will share your feedback
diagrams with the class.

Are these potential feedback loops positive (amplifying) or negative (dampening)? How do you know?

Would these permafrost feedback loops impact only the Arctic, or do they impact the global carbon cycle? Explain your
reasoning for your answer.
Lab 6B - Permafrost: A Soil with a Past and an Uncertain Future
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