• Final Thoughts LAST TIME . . .ended here

– Turn in Long Lab Field Trip (HW-1)

– Please do HW-2 (due July 7th)

– Wed – Final Chemical Oceanography -CO2_The Oceans & Ocean Physics

Fe2+

NO3-Ca2+

OUTLINE

• Foundations of Chemical Oceanography• Periodic Table – Valence Electrons• Water – It’s Unique Properties• Dissolved Elements in SeaWater• Sources & Sinks• Carbon Dioxide & the WORLD Ocean

– Intro to Global Warming

• Residence Times of Elements REMOVE?

– When sources/ sinks in balance – ocean is steady state– At steady state – can define the amt. of time

For total mass of an Element (e.g. Na) to be replaced– aka Residence Time (how long it is in the ocean)

– Residence Time • = mass of element present / rate of input or removal

• Na– 1.472 x 1011 kg yr-1 tons/ year / 2 x108 tons/yr-1 Na/year = 70 million years!

Recall - Periodic Table _Valence Electrons

Outer valence electrons (= e-) participates in bonding of Elements

e.g.CO2 carbon dioxide

.. ..O::C::O ‘‘ ‘’

Covalent bondSharing e- O=C=O

CO2

4 e- = (.)6 e- = (.)

• CO2– Aka, dry ice O=C=O– More CO2 you add

• the more acidic the water

MORE acidic

• Carbon Dioxide & the WORLD Ocean– Is human released (= anthropogenic) carbon dioxide (CO2)

• Changing the Earth’s Climate? ?– CO2

traps heat in earth’s atmosphere as a greenhouse gas

» Other gasses: CH4 (methane), CFCs, H2O

CO2, CH4 (methane),CFCs, H2O

• Who/ where is the real contribution(s)

Source: Source: U.S. Energy Information Administration (EIA)

Per Capita and Total Carbon Dioxide Emissions, 2005

CO2 emissions in tons per person Total CO2 emissions in million tons

• Two International Research Programs– Joint Global Ocean Flux Study (1988-1998)– World Ocean Circulation Experiment (1990-2002)

• To estimate oceanic storage of CO2– Oceans ~could account for 48% CO2 released thru human activity– Greatest CO2 in Deep waters: N. Atlantic & intermediate Atlantic, S. Oceans

» ` why it this?

» to be continued

• Carbon Dioxide & the WORLD Ocean– Increase in CO2 in Atmosphere Increase CO2 in World Oceans

– Concurrently seen increase in pH (more acidic) surface waters• diff of ~ 0.4 pH (not a big deal?)

RecaLL

0.4 diff =

4Xs more acidic!

Acidic means

more H+s donating

vs

Basic

H+ accepting. . .

• Marine Carbonate System and pH– Little CO2 exists as gas in Seawater,

• Mostly in chemical form: Carbonate Buffering System

• 0.4 pH diff. in Oceans b/c of Carbonate Buffering System– Favors formation of Carbonate and (H+) (see below)

This lowering of pH (more acidic) effects dissolution rates of phytoplankton shells?>

Shells dissolve shallower recall lysocline

calciteCa2+CO3

2-

MORE acidic

• Marine Carbonate System and pH

• Anthropogenic (Human produced) Carbon Dioxide – 2 major sources:

• Burning of fossil fuels

• Deforestation

How much have atmospheric CO2 levels risen since 1800?Challenge Question

Year Amount1800 – 270 ppb2004 – 380 ppb (30% increase)

• Anthropogenic (Human produced) Carbon Dioxide – 1958, David Keeling (Scripps Institute)

• Mauna Loa Observatory, HI

• CONTINUOUS (daily) CO2 measurements,– Sawtooth pattern indicates variation due to:

» Warm seasons: plants consume CO2 (drops) » Cold seasons: animals, plants release CO2 (rise)

Trend indicates Increased atmospheric CO2 levels b/c~ burning of fossil fuels. .

• Anthropogenic (Human produced) Carbon Dioxide – Fate of anthropogenic CO2 in Atm. is uncertain

• Sources/sinks reveal discrepancy ~ 2 gigatons (Gt) – i.e. there is less CO2 in atmosphere then should be present

– Based on what know about SOURCES & Sinks

– The MISSING Carbon Problem: addition Puzzle for Climate modeling.

• Estimation of the Sources & Sinks of Carbon to the Atm.

– Req. understanding of ~ The GLOBAL Carbon Cycle– What is it?

• The exchange of Carbon b/w various carbon reservoirs via – bio-geo-chemical processes

– Amts. in Gigatons (Gt)

• The GLOBAL Carbon Cycle– Total Carbon in Earth Reservoirs: Sources

• 1) mainly stored in Sedimentary rocks– e.g. limestone or dolomite ~82,370,000 Gigatons (Gt)

• 2) as organic carbon buried in sediments ~15,500,000 Gt

• 3) CO2 dissolved in world Oceans ~ 36,000 Gt– More then fossil fuels, the atm. Living organism combined

CaMg(CO3)2

Ca2+CO32-

123

• The Global Carbon Cycle– Residence Time also Important

• Scientists interested in process that move Carbon from reservoir to another

• Small Changes in Reservoir MAY have profound effects

• Large Reservoirs may exert disproportionate influence on small reservoirs– Organic carbon as Fossil fuels ~residence time: thousand years

LAND OCEAN

• The Global Carbon Cycle - Residence Time also Important• Temporal scales exist over which Carbon transfer ~ ranges

– e.g. Months thousands of years

• Thus Scientists Recognize 3 diff Carbon Cycles based on

their time scales: What are they?– 1. Short term Organic carbon cycle

» Atm & biosphere (seasonal - Keeling Curve 1958-)

– 2. Long-term Organic carbon cycle

» Formation of fossil fuels (burial of organic carbon (dinosaurs, plants))

– 3. Long-term InOrganic carbon cycle

» Storage of Carbon in rocks –

• Long Term Inorganic cycle – best represented here– From CO2 trapped in Ice Core measurements (Antarctic)

– Together all 3 cycles• Influ. atm CO2 over

– Long Time scales

• CO2 vs Temp correlate – Spark a large debate . . ..

CO2

Avg. EarthTEMP 13*CVarying/time

Petit et al., 1999, Nature 399, 429

http://upload.wikimedia.org/wikipedia/commons/1/1c/Carbon_Dioxide_400kyr.png

• Summary– No Questions CO2 is on the Rise 300ppm

• Unlike never before– Leading to Higher temperatures on earth

– What will happen?

– Major climate changes???

» More hurricanes, storms, floods etc.

» Quite possibly – only one way to find out

» Wait and see . . ..

SUMMARY- / Confirming your knowledge• How does CO2 in the atmosphere influence the Earth’s Climate?

– Serves as a Greenhouse gas

• What holds more CO2 the Oceans or Atm?– Oceans; thus small changes in ocean conditions

• large effects on atmosphere, warming/cooling (climate change)

• Where is most of the earths carbon stored?– Rocks (CaCO3) limestone

• CO2 & O2 undergo rapid changes via biological activity in Oceans from– phytoplankton (photosythnesis) & animals (respiration); what do they do?

• CO2 is consumed (phytoplankton) O2 released

• O2 is comsumed (animals/zooplankton), CO2 is released

• Storage of Carbon in Oceans~ only understood by quantifying:– The production (photosynthesis),

– The sedimentation

– Burial/subduction in ocean crusts

• SUMMARY– Humans have been adding Considerable CO2 to Atm for

• 100 years

– The world ocean has absorbed 48% of anthropogenic CO2 increasing Ocean acidity (lowered the pH)

• LONG TERMS RESULTS -- Not Clear?• Speculative . . . But probable – real climate changes

How does this CO2/temp. change affect climate? To be continued...

• Lets get informed/Involved?– Watch the Movie 90min http://www.youtube.com/watch?v=wnjx6KETmi4

Inconvenient Truth Trailer

Controversial Inflection pointsMinor issue – does cast doubt on presentation-brought to light by nut jobs. ..

http://www.youtube.com/watch?v=UOqms6REmC8&feature=related

http://www.youtube.com/watch?v=4_aRKRyB7UE&feature=related

Will ask 2 basic Questions from about glaciers and worldwide temperature