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The Carbon Cycle

(and a Brief Overview of Climate Science)

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Objectives

• To be able to summarize Earth’s carbon cycle.• To be able to draw the carbon cycle. • To be able to evaluate and discuss issues

related to climate change.

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What do you know about the carbon cycle?

• For a minute, or two, think about what you know about the carbon cycle.– You can discuss it with your neighbor.

• Share what you know.

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NASA VIDEO ON CLIMATE DATA

• http://www.youtube.com/watch?v=u68E3SubjFY

• What are the sources of warming, according to NASA’s data?

• What is happening due to the freeing of carbon from the long term carbon sinks?

• Where is NASA’s data coming from? – Are the data reliable?

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Carbon Cycle Illustrated

The change to the carbon cycle has taken the form of the large scale burning of fossil fuels.

Important note, the ocean is a significant carbon sink. Remember, carbon dioxide reacted with water creates carbonic acid (acidification of the oceans).

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Carbon: Building Block of Life

• Carbon is the key to the structure of all life on Earth. – Why we say that life is carbon based.

• It is the essential component of all organic molecules that make up your body. Examples are– Carbohydrates – Proteins– Fats

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Carbon Flow• Carbon continually flows through the

environment.– Flows through living things and back again.– There are natural carbon sinks, where carbon is

stored. – Some of the carbonic sinks are living organisms while

others are not.• Living would be forests and prairies (in the massive root

systems). • Other sinks are in mineral form – like hydrocarbons (fuel).

The oceans are major carbon sinks.

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Carbon in the “abiotic world”

• Carbon, besides as living organisms, can be found in:– Carbon dioxide gas.– Bicarbonate – dissolved in water.– Fossil fuels (hydrocarbons) – underground

deposits of oil, natural gas (methane), and coal.– Carbonate rocks such as limestone.– Dead organic matter – the humus of soil.

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Carbon Values

Petagrams is a metric unit of weight.

1 petagram = 2,204,622,621,850 lbs

Or

1,000,000,000,000 kg

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Simplest Transfer

• Simplest transfer between occurs between plants and animals.– We breath out carbon dioxide and plants “breath

it in.” – Plants convert carbon dioxide, combined with

sunlight, into glucose (carbohydrates) – part of the plants structure.

– Carbon moves through biotic world as one organism eats another.

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Return to atmosphere

• Carbon dioxide is returned to the air through animal respiration and decomposition of dead organisms.

• The burning of fossil fuels and wood adds a significant amount of “sequestered” carbon to the atmosphere.– Sequestered means trapped, also means stored.

• Methane is also a source of Carbon (we burn it off as part of oil production – also other sources (ex. . Livestock, landfills, and bogs/wetlands).

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Carbon Sinks

• Structures or areas that store carbon over long periods of time.

Global warming is caused by our allowing carbon to escape from the long term carbon sinks.

This usually is through burning fossil fuels but is also caused by deforestation and plowing of grasslands (like our prairies).

Iowa alone has lost 1.3 million acres of grassland over last 10 years.

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Carbon Dioxide Concentrations in the Atmosphere

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Findings by 4 Climate Study GroupsNASA, NOAA (National Oceanic and Atmospheric Administration), Berkeley Earth (a team of non-climate scientists – mostly physicist), and a group of European scientists (as well as many others), have all found the same trend – Earth is warming and has warmed significantly over the last 150 years.

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“Chasing Ice”

• Glacier Calving• https://www.youtube.com/watch?

v=hC3VTgIPoGU

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Global Warming

• Is global warming happening? Almost all climate scientists say yes.– Two possibilities: human caused, not human

caused.– What should we do about it?

• http://www.economist.com/node/21533360– “The Heat Is On” – from The Economist (October

2011).

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SciShow on IPCC

• https://www.youtube.com/watch?v=dGG7JGT4Fdo

• Intergovernmental Panel on Climate Change.– Climate scientists from around the world.– Using science to analyze changes in climate.• This is a scientific endeavor and uses the scientific

method.

• What does the IPCC report say?

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Dr. James Hansen

• http://www.economist.com/blogs/babbage/2012/08/james-hansen-climate-change

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Draw the carbon cycle

• I now want you to draw the carbon cycle. • You can use your notes, your books, or do it by

memory.• You can do this with your table mate, if you do

not have a table mate, then you can work with the person(s) ahead or behind you.

• This is worth 10 points, I expect you to turn it in. If you do not do it in class, it is homework.