Biogeochemical Cycles

• 20 essential inorganic elements for living organisms.

• Unlike energy - essentially no input of inorganic nutrients

• Essential elements present in finite amounts– recycled from dead tissue and wastes

Earth’s ecosystems are maintained by a constant influx of energy

SolarEnergy Autotroph Herbivore Carnivore

Respiratory Loss

Transformation Loss of Energy

Biogeochemical CyclesCycling of chemical elements between living and non-living

portions of the earth’s ecosystems

Biotic

Abiotic

Uptake

DecompositionRespirationExcretion

Abiotic Reservoirs for Essential Elements

• Lithosphere (bedrock and soil)

• Atmosphere

• Hydrosphere (especially the ocean)

Carbon CycleWhere do we find carbon?

• Air (carbon dioxide)• Dissolved in water:

– Carbonic acid– Carbonate and bicarbonate ions

• Rocks and soil: – e.g. limestone calcium carbonate

• Fossil fuel deposits: – Coal, oil, natural gas

• Living organisms - organic molecules:– Carbohydrates, proteins, fats)

Relative amounts of carbon in Reservoirs and living and dead Tissues

• Atmosphere = 1

• Living organisms = 0.66

• Decaying Organic Matter = 6.7

• Fossil Fuels =14.3

• Ocean Waters = 50

• Carbonate Sediments (limestone) = 29,000,000

Types of Reservoirs

• Active Reservoirs

• Storage Reservoirs

Active Reservoirs for Carbon

• Atmosphere – Carbon dioxide

• Hydrosphere – Carbon dioxide

– Bicarbonate ions

– Carbonate ions

Storage Reservoirs for Carbon

• Carbonate rocks– limestone

• Fossil fuels – Coal

– Oil

– Natural Gas

Chemicals move from one abiotic Reservoir to another

AtmosphereCO2

Carbonic acid Bicarbonate ion Carbonate ion

+ Calcium

Calcium CarbonateSedimentaryRock

(Limestone)

Volcanic Activity

Hydrosphere

The Carbon Cycle• Atmosphere contains

– 0.037% (370 ppm) carbon dioxide

– @720 trillion kg Carbon

• Annually in photosynthesis– @120 trillion kg of carbon –

– 1/6 of atmospheric CO2

Why photosynthesis does not deplete atmospheric CO2

• Rapid recycling (high Mobility)

– Biotic and Abiotic

• Oceans stabilize atmospheric concentration

• Release from storage reservoirs

Reason 1: There is great mobility of carbon

Photosynthesis removes CO2 from the atmosphere

Solar Energy

CO2 + H2O carbohydrate + oxygen

Chlorophyll

120 trillion kg

Reason 1: There is great mobility of carbon

Respiration/Decomposition returns CO2 to the

atmosphere

Carbohydrate + Oxygen CO2 + H2O

Plants 60 trillion kgheterotrophs (decomposers) 60 trillion kg

Balance between photosynthesis and respiration

• Plants remove 120 trillion kg of Carbon– Photosynthesis

• Respiration returns 120 trillion kg of Carbon– Plant respiration 60 trillion kg of Carbon– Heterotrophic respiration 60 trillion kg of

Carbon

Seasonal Variation in atmospheric carbon dioxide

Conc. carbon dioxide

J F M A M J J A S O N D

Maximum Photosynthesis

Month

Ocean Help Stabilize Levels of Atmospheric CO2

Co2 + H2O H2CO3 H+ + HCO3

H+ + Co3 (carbonate ion)

Carbon is stored in more forms than just CO2 in the oceans

Carbonic Acid

bicarbonate ion

Atmosphere

Reactions are reversible

Ocean

Oceans help stabilize Levels of Atmospheric CO2

Ocean AtmosphereEquilibrium

Ocean Atmosphere

Ocean Atmosphere

Aquatic/Atmospheric Reservoirs

30 to 50% of Atmospheric carbon dioxide in the ocean in a few years

Currently a Net flux of carbon into ocean

Carbon Dioxide Net Flux 2 trillion kg Atmosphere

OCEAN

107 trillion kg

105 trillion kg

3. Release from storage Reservoirs: Fossil Deposits

• Fossil fuels– Coal, oil and natural gas– Carboniferous - 345-280 million YBP

• Carbonate rock – Shells of marine animals – Limestone and Dolomite

• Slow exchange– Carbon “locked up” for millions of years

Amounts in the Storage PoolsCompared to the Atmosphere

(Atmosphere = 1)

• Fossil Fuels (14.3)

• Carbonate Sediments (29,000,000)

How Does Carbon Get From the Storage Reservoirs to the Active

Reservoirs?

• Burning of fossil fuels• Subduction and volcanic activity

Plate Tectonics

Plate Tectonics

Plate tectonics

• Plate tectonics – Move apart

– Slide past

– Override (subduction)

CO2

Changes in atmospheric carbon dioxide

• In the past 150 years, there has been a substantial increase in atmospheric carbon dioxide

Increase in atmospheric carbon dioxide

Reasons for Increased Atmospheric CO2

• Increases in past 140-150 years because of:

• Deforestation

• Current mostly tropical regions Agricultural expansion

• Industrialization (about 75%)

Estimates of Carbon ReservoirsTrillion kg of carbon

• Soil Organic Carbon1,500

• Litter 100

• Live Biomass 650

• Total 2,250

• Atmosphere 720

• Soil + litter + live biomass (2,250 ) is 3X’s the atmosphere (720)

Forests as Carbon Sinks

TreeCarbon dioxide

Photosynthesis

Carbon is stored in the plant’s tissues (roots, stems,

and leaves)

Carbon is incorporatedinto the soil

Decomposerrespiration

Plant respiration

Carbondioxide

Young Forests and Mature Forests

Gross Primary Production

Respiration

Carbon Net Primary Production

YOUNG MATURE

Young Forests and Mature Forests

Gross Primary Production

Respiration

Carbon

Biomass

YOUNG MATURE

Carbon Removed from the atmosphere

Forests as carbons sinks (Mature Vs. Young Forests)

• Young forests– Accumulate more carbon than they give off in

respiration – Represent smaller “carbon sinks”

• Mature forests – Approximate balance between photosynthesis

and respiration– Larger sinks for carbon

Cutting and Burning Forest returns large amounts of carbon to the atmosphere

• What happens when forests are converted to cropland?

Reasons for increased carbon dioxide

• Industry– Fossil fuel burning 6.9-7.0 trillion kg of

carbon (77%)

• Deforestation– 1.8-2.0 trillion kg of carbon (22%)– mostly in tropical regions of the world

• Consequences?

Greenhouse EffectGreenhouse Glass

Energy AbsorbedCarbon dioxide lets Short wave radiation pass through

0.1-7.0 microns

long-wave radiation is

absorbed8-12 microns

Solar Radiation

Greenhouse Gases

Earth

In comingradiation

Carbon dioxide

•Energy absorbed by carbon dioxide is radiated in all directions.

•Some of this energy is absorbed by the earth causing the greenhouse effect.

CO2 is essentiallytransparent to

solar energy

Greenhouse Gases

• Gas % Rel. Efficiency

– Contribution

• CO2 65% 1

• Methane (CH4) 20% 21

• Nitrous Oxide (N2O) 5% 270

• CFCs >5% 15,000

• CFC = Chlorofluorcarbons

Greenhouse Gases

• Gas Atmospheric Conc. (ppm)

– CO2 370

• CFCs 0.000225

• Methane* 1.6

• Nitrous Oxide 0.31

Methane Production (20% Global Warming)

• Natural Sources (40%)– Decomposition of detritis

• Human Sources (60%)– Land fills– Natural Gas Management– Livestock Production

• Ruminant 25-500 liters/day

• Manure Management

• 37% of human sources

• 2% of global warming

1996 (C02 from fossil fuels, cement production, gas flaring)RANK NATION CO2 TOT * CO2/ CAP** 1 UNITED STATES OF AMERICA 1446777 5.37 2 CHINA (MAINLAND) 917997 0.76 3 RUSSIAN FEDERATION 431090 2.91 4 JAPAN 318686 2.54 5 INDIA 272212 0.29 6 GERMANY 235050 2.87 7 UNITED KINGDOM 152015 2.59 8 CANADA 111723 3.76 9 REPUBLIC OF KOREA 111370 2.46 10 ITALY (INCLUDING SAN MARINO) 110052 1.92 11 UKRAINE 108431 2.10 12 FRANCE (INCLUDING MONACO) 98750 1.69 13 POLAND 97375 2.52 14 MEXICO 95007 1.02 Total* = 1,000 metric tons of carbon, metric tons per capita**

Changes in Carbon dioxide Emissions

China surpassed USA’s emissions in 2006 by 8%, China’s CO2 emissions are now estimated to be about 14% higher than

those from the USA

Current Total CO2 Emissions (2007)Five Leading Nations

• Country Total (%)– China 24– USA 21– EU-15 15– India 8– Russian Federation 6%

• Total 71%

Per capita Emission Top Five

• Country Capita (metric tons)– USA 19.4 – Russia 11.8– EU-15 8.6– China 5.1– India 1.8

China Lacks Technology to Curb Emissions

How much CO2 does the earth’s atmosphere

accumulate each year?

Global Carbon Emissions Breakdown Giga tons (Trillion tons)

• Global Emissions: 8.7-9.1– Fossil fuels: 6.9-7.0 (77%)– Land-use change (deforestation): 1.8-2.0 (22%)– Other (cement production, gas flaring): 0.1 (1%)

• Global Absorption:8.7-9.1– Remains in atmosphere:4.5– Absorbed by oceans:2.3– Absorbed by vegetation:1.9-2.3

Inter-Glacial CO2

2000 1800 1000120014001600

Year (AD)

The Industrial Revolution Caused a Dramatic Rise in CO2

Could Changes in Carbon Dioxide alter world temperature

• Long-term temperature change based on Vostok ice (Antarctic) –

• Global data land base thermometers:– 0.6 Celsius (1.2 degree Fahrenheit)-

World Temperature

Changes in World Climate

• Five of the six warmest years in meteorological history occurred in this century

• Nineteen of warmest years in global meteorological history occurred in the past 20 years

• 2006 5th warmest year

• 2007 2nd warmest year

Boulder Glacier, Glacier National Park, Montana 56 years later, from the same point.

July 1932 July 1988

Departure from World Warming Trend in 1992 and 1993

Trends in world temperature• Increasing temperature interrupted 1992 &

1993

• Eruption of Mount Pinatubo in the Philippines

• Sulfur dioxide – two-year cooling trend– sulfur dioxide - nucleus for water droplets to form

• Increase low cloudiness – cause world temperatures to cool – warming resumed in 1994

Some consequences of global warming?

• Some parts of the world become cooler.• Loss of biological diversity• Plant growth faster with less water loss• Patterns of world crop yields change• Insect damage to crops increase• Human tropical diseases may spread• Sea level rises• Climate less predictable

Unexpected Climatic Change

Some parts of the world may become markedly cooler!!

Ocean Conveyor Belt

Loss of pollinators

Loss of Biodiversity

• Hummingbirds – pollinate flowers in mountains – Wintering birds migrate at a precise photoperiod

• Cannot rely on local climate• Arrive when plants are in flower

• Flowering plants– Specialized for hummingbirds– Flower controlled by temp. – Global warming means earlier flowering

• Pollinators arrive too late• Cascading interactions:

– Pollinators have no resources– Plants set no seeds– Herbivores and seed predators decline– Predators decline

What are the Possible Consequences of Global Warming?

• Loss of biological diversity– Loss of migration routes due to habitat

destruction– Encouragement of aggressive, exotic species

Polar Bears

– Decline in polar bears

• 20,000 – 25,000

• Polar bears are now Federally listed

• An “endangered” species is one that is in danger of extinction throughout all or a significant portion of its range. A “threatened” species is one that is likely to become endangered in the foreseeable future.

Effect of elevated CO2 on plant growth

• Generally plants

– Higher photosynthesis as CO2 increases

– Lose less water

• Negative effects

– Higher temperature and drought

CO2 H2O

Crop Yields

• Generally increased crop yields – World’s three major crops:

• Rice, corn and wheat

• Tropical regions – Higher temperatures and reduced moisture– Likely will decrease crop yields

• Overall no expected change world wide

• Local Change ?

Some consequences of global warming?

• Some parts of the world become cooler.• Loss of biological diversity• Plant growth faster with less water loss• Patterns of world crop yields change• Insect damage to crops increase• Human tropical diseases may spread• Sea level rises• Climate less predictable

Insect Damage to plants may increase due to global warming

• Warmer temperatures– Increase insect metabolism

• Plants will grow faster– Less nitrogen per unit of plant tissue– Insects eat more plant to obtain nitrogen

• Insect pests of crops– Spread into new areas– European corn borer

• Europe and North America

Tropical human diseases may spread northward

• Malaria

• Dengue Fever – Break bone fever– Four related Viral disease transmitted by

mosquitoes– Symptoms:

• Rash, fever,

• Joints ache (Break bone fever)

Dengue hemorrhagic fever

• Prior immunity: People infect by more than one strain of virus

• Bleeding breaks through the skin (hemorrhagic disease) – small blood vessels (capillaries)

• 5% of cases fatal

Hemmorhagic Disease

Asian Tiger Mosquito

–Now found in Peoria, Illinois

Vectors Aedes aegypti Aedes albopictus (Asian tiger mosquito) -

Transmitted by anopheles mosquito – occurs every where but Antarctica

Sea level rise at an accelerated rate

• Average global sea level rise – 10- 25 cm last 100

years– Melting of ice &

expansion of water• Unmitigated (red)• Stabilization:

– 750 ppm CO2 (blue) – 550 ppm CO2 (green)

• Gray no climate change .

2.5 cm = 1 inch

20 cm = 8 inches

Consequences of rising sea level

• Estuary systems

• Quality of coastal fresh water

• Coastal settlements threatened include, Tokyo, Los Angeles, Cairo, New York , Shanghia, Bangkok

Melting of land ice will contribute to Sea Rise

• Why will only melting of land ice contribute to sea level rise?

• Where is most of the land ice?– Antarctica– Greenland

• West Antarctica ice sheet– 6 meters

Climate will be less predictable and climatic extremes will increase

• Will climate change increase severity or frequency of major storms, including hurricanes – Some evidence relates frequency of severe hurricanes

to global warming

• U.S. NOAA (National Ocean and Atmospheric Administration) – Steady increase in precipitation derived from extreme

one-day precipitation events

• Insurance companies are paying out more money because of unexpected disastrous storms

Kyoto Protocol • Adopted on 12 December 1997 in Kyoto, Japan

– (UNFCCC)

• Terms for implementation– 55 parties to United Nations Framework Convention

on Climate Change (UNFCCC) • 1992 Earth Summit

– At least of 55% of 1990 CO2 emissions– Effective February 16, 2005 – 178 signatories (as of April 2008)

• 61.6% of emissions

Kyoto Protocol• Reduction in Emissions or Trading Emissions:

– 6 key greenhouse gases – below 1990 base level– Period 2008-2012

• 5.5 % Developed countries collectively • Industrialized nations 5.2%

– 8% Switzerland– 7% USA (at the time USA produced 37% of CO2

emissions)– 6% Canada, Hungary, Poland, Japan, Russia– Stabilize Ukraine, New Zealand – Norway +1%,– Australia +8%– India and China no limitations

Kyoto Protocol USA

• President Clinton

• President Bush

• Carbon credits– Companies with excess emission purchase

credits from companies with excess allowances– Green companies: plant trees to absorb excess

carbon dioxide and sell carbon credits to companies with excess allowance.

Carbon emission from fossil fuel burning Selected Total Per capita Tons/$ Growth Countries (million tons) (tons) GNP* 1990-94

USA 1,371 5.26 210 4.4%

China 835 0.71 330 13.0

Russia 455 3.08 590 -24.1

Japan 299 2.39 110 0.1

United Kingdom 153 2.62 150 -0.3

Poland 89 2.31 460 -4.5

South Korea 88 1.98 200 43.7

* tons per million dollars

Planting Trees

• In the tropics:– one trees is planted for every 10 cut– Africa one planted for every 29 cut

• World wide we would have to plant 1,000 trees per person annually

• USA --we would have plant 4,500 trees per person, at 1,200 trees/acre this is 3.75 acres per year