A bit of background on carbonates. CaCO 3 (solid)

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1 A bit of background on carbonates CaCO 3 (solid)

2 Organisms need both carbon dioxide and carbonate Kleypas et al 2005

3 The two pumps put CO 2 into the deep ocean

4 The long term record of climate change Or: 60 million years of climate change in 80 minutes

5 Controls on climate Tectonics Ocean circulation Orbital parameters

6 Oxygen isotopes have different controls on different time scales

7 The reasons for the isotopic change has 2 forcings colder More ice

8 Isotopes record broad climate change But why did it occur?... Tectonics..

9 The Cretaceous world

10 Circulation in the Cretaceous was restricted at high latitudes

11 Ocean circulation in the early Tertiary

12 Eocene continental placement

13 Oligocene continental placement

14 In the Tertiary, the Southern Ocean began to open The Cretaceous world comes apart. At the same time the Southern Ocean opens, the Atlantic began to open

15 Ocean circulation at 25 Ma

16 The reasons for this isotopic change has 2 forcings colder More ice

17 Earliest Miocene Circulation

18 Change in continental placement through the tertiary controls circulation and climate

19 The final piece The isthmus of Panama closes at 3.3Ma The basins are set (as today) Northern hemisphere glaciation begins at ~2.4 Ma Pulsing at ~40ka periodicity.

21 The broad brush misses lots of detail colder More ice

22 Tectonic control orbital control Orbital parameters were always an influence but as the basin shape is set up they become more influential. Also, we have a better record and can see the record of glacial pulsing in more detail. What are the orbital parameters?

23 Glacial cycles of the last 2 million years

24 Orbital changes cause changes in insolation Insolation at different times of the year has different effects on global climate The earth s orbit varies in shape on long time scales. These changes vary total insolation And they vary seasonal insolation.

25 Sum total of the orbital control Gives us an added wave pattern that resembles the 18 O record Is the Is tilt the of elliptical-ness the poles and of it s the variation orbit

26 Sum total of the orbital control Gives us an added wave pattern that resembles the 18 O record

27 Climate record for the last 120ka 18 O in the sediment record Emerson and Hedges 2008

28 The congress effect on climate tectonics Orbital snowball

29 Climate record for the last 120ka 18 O in the sediment record Emerson and Hedges 2008

30 Orbital parameters and climate are similar

31 Glacial cycles of the last 2 million years Past 2 million years shift from a 40k to 100k cyclicity

32 Climate and circulation feedback Past 300k 3 cycles

33 Record of CO 2 in the atmosphere The record of CO 2 levels in the atmosphere has the same pattern as ice volume

34 Rapid climate change Ocean circulation between glacial and interglacial modes The triggers that can shift the circulation between modes can be rapid. Modes can switch like a switch

35 The conveyor belt circulation And thermohaline circulation moves CO 2 through the system

36 Last glacial shutdown of NADW The polar front moved south. The location and character of NADW water formation changed

38 The NADW that formed was less in volume and shallower

39 The 13 C reflects traces the concentration of CO 2 in the deep ocean Curry and Oppo, 2005 Our tracer is 13 C

40 NADW became NAIW Curry and Oppo, 2005 Our tracer is 13 C

41 The deep ocean had more CO more DIC Less DIC It looked more like the Pacific today than the Atlantic today Holocene ( ka) Glacial (20-21ka) Southern Ocean 4000

42 The biological pump interacts with the excess CO 2 we are putting into the atmosphere. The marine system is taking up CO 2 in surface waters fixing it to organic carbon and carbonate and Putting it into the deep ocean. Because most of the deep ocean is capped by the thermocline, the respired CO 2 remains there.. If carbonate dissolves then the capacity of the water is increased (balanced by the alkalinity)

43 Controls on the fractionation of 13 C Water downwells: DIC enriched Low nutrients High O 2 13 C 12 C 13 C 13 C 12 C 13 C 12 C 12 C 13 C 13 C DIC (in Water) more depleted with increasing age 12 C 12 C 12 C 13 C 12 C 12 C 12 C 12 C C C 12 C 12 C 13 C Porewaters very sensitive to remineralization can be very depleted in 13 C

44 Controls on the distribution of CO 2 Water downwells: Low nutrients High O 2 low CO 2 content CO 2 CO 2 CO 2 CO 2 CO 2 CO 2 Corg DIC Corg DIC Corg DIC Corg DIC DIC DIC DIC content of Water increases with increasing age DIC DIC Corg Corg Corg DIC Corg DIC Corg DIC DIC Corg Carbonate Sediments are a source and sink of carbon, both Corg and CO 2

45 Record of CO 2 in the atmosphere through time Moana Loa Vostok ice core Temperature records change in sync with carbon dioxide records

46 We now have all the pieces: Ocean controlled carbon cycling There is a balance between atmosphere and ocean If ocean circulation is changed there is a moderately long-term effect on carbon cycling.

47 The CO 2 Climate connection How much CO 2 in the ocean controls the levels in the atmosphere How fast the ocean circulates controls can change the amount of CO 2 in the atmosphere (to change climate) The carbon cycle IS the climate cycle.

48 The carbon cycle summary

49 Two pumps put CO 2 into the deep ocean

50 Changes in circulation affect the CCD In the glaciation the CCD rose about 1000m More dissolved CO 2 stayed in the ocean and it came out of the atmosphere.

51 To reiterate.. The depth of the CCD shallowed in the LGM

52 Long term change in circulation has long term effects on CO 2 cycling The CCD permanently dropped when deep circulation as we know it began after the Cretaceous (when the Atlantic opened). This permanently changed the oceans CO 2 capacity

53 The Wilson cycle Are the very long term processes that affect CO 2 and climate

54 carbon cycling time frames Longer: The tectonic time Frame the Wilson Cycle The sedimentary time frame ~ millions-thousands yrs Shorter: The bio pump (organic and carbonate) Respiration and dissolution

55 Timescales Climate change Ecosystems ~ 10,000yr sediments

56 The importance of limestone Most of the carbon stored near the surface of the earth is found as CaCO 3 skeletal remains. Organic carbon is significant, but limestone is the largest reservoir

57 Oil reserves

58 Carbonate sediments

59 Carbonate sediment-carbon cycle Weathering of carbonate consumes CO 2 Organic carbon sequestration occurs on the same time frame as carbonates These both contribute to the mid-long term cycling ,000 yrs s million yrs

60 Very long term changes in Atmosphere CO 2 content Hothouse eras Rise of vascular plants Limestone and Oil formation

61 Not just CO 2 changed Increasing oxygen Rise of vascular plants As CO 2 decreases O 2 increases. They are linked through photosysthesis respiration, and weathering.

62 Atmospheric oxygen

63 Carbon in the ocean and sediments The deep ocean reservoir is 50x atmosphereic sediment reservoir is 4 orders of magnitude larger. It is both organic and carbonate carbon.

64 The scientist view on climate John Oliver s take on the debate and for good measure: Jon Stewart on ice displacement

Welcome to ATMS 111 Global Warming.

Welcome to ATMS 111 Global Warming http://www.atmos.washington.edu/2010q1/111 Isotopic Evidence 16 O isotopes "light 18 O isotopes "heavy" Evaporation favors light Rain favors heavy Cloud above ice is