Download Important Concepts for chemical cycling

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
Transformation Loss of Energy
Solar
Energy
Autotroph
Herbivore
Respiratory Loss
Carnivore
Biogeochemical Cycles
Cycling of chemical elements
between living and non-living
portions of the earth’s ecosystems
Decomposition
Respiration
Excretion
Biotic
Uptake
Abiotic
Abiotic Reservoirs for Essential
Elements
• Lithosphere (bedrock and soil)
• Atmosphere
• Hydrosphere (especially the
ocean)
Carbon Cycle
Where 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
CO2
Atmosphere
Hydrosphere
Carbonic acid
Bicarbonate ion
Carbonate ion
+ Calcium
Volcanic
Activity
Sedimentary
Rock
(Limestone)
Calcium Carbonate
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
120
trillion kg
Photosynthesis removes CO2 from the atmosphere
Solar Energy
CO2 + H2O
carbohydrate + oxygen
Chlorophyll
Reason 1: There is great mobility of carbon
Respiration/Decomposition returns CO2 to the
atmosphere
Carbohydrate + Oxygen
CO2 + H2O
Plants 60 trillion kg
heterotrophs (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
Maximum Photosynthesis
Conc.
carbon
dioxide
Month J F M A M J J A S O N D
Ocean Help Stabilize Levels of
Atmospheric CO2
Carbon is stored in more forms
than just CO2 in the oceans
Atmosphere
Ocean
Carbonic
Acid
bicarbonate ion
Co2 + H2O
H2CO3
H+ + HCO3
H+ + Co3
(carbonate ion)
Reactions are reversible
Oceans help stabilize Levels of
Atmospheric CO2
Ocean
Ocean
Ocean
Atmosphere
Equilibrium
Atmosphere
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 Pools
Compared 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 Reservoirs
Trillion kg of carbon
•
•
•
•
•
•
Soil Organic Carbon
1,500
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
Carbon
dioxide
Tree
Carbon
dioxide
Photosynthesis
Plant respiration
Decomposer
respiration
Carbon is stored in the
plant’s tissues (roots, stems,
and leaves)
Carbon is incorporated
into the soil
Young Forests and Mature
Forests
Gross Primary
Production
Net Primary
Production
Carbon
Respiration
YOUNG
MATURE
Young Forests and Mature Forests
Carbon Removed from
the atmosphere
Gross Primary
Production
Biomass
Carbon
Respiration
YOUNG
MATURE
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 Effect
Solar
Radiation
Greenhouse
Glass
long-wave
radiation is
absorbed
8-12 microns
Carbon dioxide lets Short
wave radiation pass through
0.1-7.0 microns
Energy Absorbed
In coming
radiation
Greenhouse Gases
Carbon dioxide
CO2 is essentially
transparent to
solar energy
Earth
•Energy absorbed by carbon dioxide is
radiated in all directions.
•Some of this energy is absorbed by the earth
causing the greenhouse effect.
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
CFCs
Methane*
Nitrous Oxide
370
0.000225
1.6
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
– China
– USA
– EU-15
– India
– Russian Federation
• Total
Total (%)
24
21
15
8
6%
71%
Per capita Emission Top Five
• Country
–
–
–
–
–
USA
Russia
EU-15
China
India
Capita (metric tons)
19.4
11.8
8.6
5.1
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
The Industrial Revolution Caused a
Dramatic Rise in CO2
2000
1800
1600
Inter-Glacial CO2
1400
Year (AD)
1200
1000
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
CO2
H2O
• Generally plants
– Higher photosynthesis as CO2 increases
– Lose less water
• Negative effects
– Higher temperature and drought
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
Vectors
Aedes aegypti
Aedes albopictus (Asian tiger
mosquito) -
Asian Tiger Mosquito
–Now found in
Peoria, Illinois
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
Countries
Total Per capita
(million tons)
(tons)
Tons/$ Growth
GNP* 1990-94
USA
1,371
5.26
210
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
4.4%
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