Carbon Cycle

Explain how chemical and physical processes cause carbon to cycle through the major earth reservoirs.

D19

All living organisms are built of carbon compounds. It is the fundamental building block of life.

Carbon is cycled among Earth's reservoirs, just like water.

Why study the Carbon Cycle?

Carbon can form four bonds at a time. It bonds with hydrogen, oxygen, nitrogen,

and other elements. It can also bond to other carbon atoms, forming a long chain of atoms

These unique properties of carbon allow it to function as the building block for living things.

Carbon is unique

There are 4 Major Reservoirs which comprise the EarthBiosphere – living things

Atmosphere – the airHydrosphere – the water

Lithosphere/ Geosphere – the ground

whshonorses.wikispaces.comCarbon is found in each of these!

Biosphere The reservoir known as the biosphere is

comprised of living things – plants, animals and everything else in between!

http://www.biology-online.org/dictionary/Biosphere

wildarunachal.org

flmnh.ufl.edu

The biosphere is all life on our planet. This includes living organisms as well as the

un-decomposed remains of dead organisms. The biosphere includes life on land and in

the oceans

Biosphere

Living things on our planet are carbon-based because most of the molecules in them are chains of carbon atoms linked together.

In the biosphere, carbon is contained within organic molecules which contain carbon, oxygen, hydrogen, and nitrogen.

Biosphere Carbon

Lecithin – triglyceride

http://www.theresilientearth.com/?q=content/biodiversity-balderdash

Atmosphere The reservoir known as the atmosphere is

comprised of the whole mass of air surrounding the Earth

http://www.merriam-webster.com/dictionary/atmosphere

kidsgeo.com

vtaide.com

Atmosphere

In this reservoir, carbon is found as carbon dioxide (CO2)

Carbon dioxide comprises less than 5 % of the atmosphere. It has a residence time of 10 years.

But, it plays an important role with regards to our planet’s temperature, as we will discuss later on.

Atmospheric Carbon

Looking forward … Greenhouse Effect

Hydrosphere This reservoir encompasses all of the waters

on the earth's surface, such as lakes and oceans.

The hydrosphere covers about 70% of the surface of the Earth and is the home for many plants and animals.

kidsgeo.com

natasha-hydrosphere.blogspot.com

Hydrosphere

In the hydrosphere, carbon mainly exists as dissolved CO2

Marine life including plankton and shellfish use this dissolved CO2 combined with Ca as calcium carbonate to form their shells and skeletons.

Hydrosphere Carbon

Lithosphere/Geosphere

This reservoir consists of the outer solid part of the earth, including the crust and uppermost mantle.

http://earthquake.usgs.gov/learn/glossary/?term=lithosphere

oceansjsu.com exploratorium.edu

The lithosphere consists of sediment and rocks of the upper crust of the Earth.

Carbon enters the lithosphere through ocean sediments and by the burial of decaying organic matter.

Lithosphere/Geosphere

Carbon can be found in the lithosphere in two forms Limestone / Dolomite - carbon in this

rock originates from the living things in the ocean. Upon their death, these organisms become part of ocean sediments and over time they convert to limestone and becomes part of the lithosphere carbon reservoir.

Coal, oil, and natural gas - these are the remains of ancient plants and plankton which have undergone geologic processes.

Lithosphere Carbon

http://eri.gg.uwyo.edu

Basic Pathways for Movement of Carbon

Diffusion – movement of substances from an area of high concentration to an area of low concentration

Respiration – the process by which cells gain energy from organic molecules which consumes oxygen and releases carbon dioxide

Photosynthesis – the process by which plants create glucose by combining carbon dioxide and water and utilizing the sun’s energy

Basic Pathways for Movement of Carbon

Eruption of Gases / Volcanic Eruptions – release of gases from the earth’s crust

Burial and Sedimentation – the process by which loose materials deposited on the Earth’s surface form layers and eventually form rock

Weathering and Erosion – the chemical and physical processes of breaking apart rocks into smaller pieces

Short-term (Fast Track)Carbon Cycle

Photosynthesis Respiration Decomposition Diffusion

beta.lpb.org

• Minutes to Years

Long-term (Slow Track)Carbon Cycle

Weathering and erosion

Accumulation of carbon-rich plant and animal material in sediments

Fossil fuel formation

This takes millions of years

beta.lpb.org

climate.be

You will learn more about these from your reading assignment tonight.

Fast Track vs. Slow Track

Sinks are ways that carbon is stored for long periods without being reintroduced to the atmosphere

Sources are ways that carbon is moved into the atmosphere

When in balance, the total carbon dioxide emissions and removals from the entire carbon cycle are roughly equal.

Currently, the sources are overpowering the sinks

Sinks and Sources

Billions of tons of atmospheric CO2 are removed from the atmosphere by oceans and growing plants, which function as ‘sinks,’

This carbon is emitted back into the atmosphere annually through natural processes also known as ‘sources.’

Overview - Natural Sources and Sinks

Animals and plants undergo respiration ◦ This moves C from biosphere to atmosphere

The oceans undergo diffusion of CO2

◦ This moves C from hydrosphere to atmosphere Volcanoes undergo eruptions which release gases

◦ This moves C from lithosphere to atmosphere. Rocks and minerals undergo weathering and

erosion◦ This moves C from lithosphere to atmosphere or

hydrosphere.

Natural Sources

Plants undergo photosynthesis; ◦ This moves CO2 from the atmosphere to the biosphere.

Oceans take in CO2 by diffusion◦ This moves carbon from the atmosphere to the

hydrosphere.

Natural Sinks

Manmade Sources – Use of Fossil Fuels

Fossil fuels form over millions of years from buried plant and animal material

When fossil fuels are burned to produce energy their carbon is released into the atmosphere as CO2.

This is the largest source of CO2 emissions globally

kids.britannica.com geothermal.marin.org thedailygreen.com

Manmade Sources – Deforestation

Trees cut down and burned Impacts temp. and stability of the soil

◦ Soil erosion◦ Inc. in temp. because soil no longer covered by

vegetation How does it affect the C cycle?

en.wikipedia.org plu.edu time.com

Manmade Sources – Cement Manufacturing

Calcium carbonate is heated to produce lime and CO2

US: 7 – 10 billion metric tons of C per year How does it affect the C cycle?

stateoftheusa.orgpmhl.co.uk

Manmade Sources – Cattle Farming Cattle burps and

flatulence Respiration How does it affect the

C cycle?

oklahomafarmreport.com

environmentalparliament.org

Manmade Sources – Rice Farming

Flooding of rice paddies causes underwater organic matter to decompose

Methane (CH4) is released How does it affect the C cycle?

Rice Farming in Louisiana

geobloggingwithmark.blogspot.com

agrariancrisis.in

geographyfieldwork.com

Rice Farming in Spain

Growing trees and plants remove CO2 from the atmosphere and store it in the biosphere.

Humans cause deforestation, which erases this key carbon sink.

How man affects sinks

Manmade Sinks - Carbon Capture and Store

Carbon sequestration Capturing C from power

plants and pumping it underground

Expensive How does it affect the C

cycle?

carboncapture.us

Manmade Sinks – Planting Trees How does it affect

the C cycle?

jiyolive.com

treehugger.com

masterfile.com

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/biogeochemical_cycles.html

http://www.actewagl.com/education/Glossary/default.aspx?letterSearch=C

http://www.eoearth.org/article/Carbon_cycle http://www.infoplease.com/ce6/sci/A0857177.html http://www.oznet.ksu.edu/ctec/Carbon/carboncycle.htm http://www.waterencyclopedia.com/Bi-Ca/Carbon-Dioxide-in-the-Ocean-

and-Atmosphere.html http://eri.gg.uwyo.edu/resources/Energy/coal/information/formation/

carbonCycle/humanEffect.asp http://www.epa.gov/climatechange/emissions/co2_human.html

References