Lecture 4 -- Oceans: Two CO2 Problems

Question 1

1. What are the two major global impacts caused by excessive CO2 emissions?1

Answer 1

Climate changed caused by greenhouse gases (CO2 & other)

Ocean Acidification - CO2 absorbed by the ocean (disrupts food webs)

Question 2

2. Why are pteropods (sea butterflies) important to the north Pacific foodweb?

Answer 2

Tiny “seabutterflies”, planktonic snails, key part of the diet of organisms in the PNW (krill salmon and whales)

acidification in the ocean dissolves their shells

Question 3

3. Where is most of the excess energy from global warming going?

Answer 3

1

Question 4

4. There is a net radiation imbalance between the equator and the poles…what two things does the energy imbalance move?

Answer 4

Global wind patterns and ocean currents

Question 5

5. The global conveyor belt is driven by the downwelling of surface water in a small number of places in the ocean…what 2 factors drive downwelling?

Answer 5

Salinity and Water Temp

How much salt in the water, what is the temp?

Question 6

6. Why are there no major downwelling areas on the conveyor belt in the north Pacific?

Answer 6

1

Question 7

7. How could climate change affect salinity of ocean water in the north Atlantic?

Answer 7

Increased temperatures mean:
More evaporation of water increases salinity.

Melting glaciers add more freshwater, diluting the salinity

Question 8

8. What could happen to the conveyor belt if salinity decreases in the north Atlantic? Describe some potential impacts if the conveyor belt slows substantially or stops.

Answer 8

The conveyer belt could slow or even stop.

Collapse of plankton stocks, increased temperature in tropics, Alaska, Low O2 in ocean means mass extinction, Cooling of northern Europe, more frequent storms and major floods.

Question 9

9. Which is currently the greatest driver in sea level rise, melting glaciers or thermal expansion of sea water?

Answer 9

Thermal Expansion!

Question 10

10. Anthropogenic CO2 emissions move carbon from a stable, storage reservoir (buried fossil fuels) into three bio-reactive reservoirs (atmosphere, terrestrial biosphere, and ocean). How much of those emissions end up in the ocean?

Answer 10

30% make it to the oceans

Question 11

11. Why does global atmospheric CO2 always drop substantially over the course of summer, and then rise during winter?

Answer 11

Warm water holds less CO2, also more sunlight means more PS which uses up available CO2

Question 12

12. What are the two main types of CaCO3? Which is less stable? How is CaCO3 used by marine organisms…give examples.

Answer 12

Calcite and Argonite.

Argonite is more soluble, less stable

Calcite used by diatoms
Argonite for clams shells

Question 13

13. Why is there a zone of undersaturated aragonite (water corrosive to aragonite) off the coast of Oregon and Washington during spring and early summer.

Answer 13

Maybe agg run off?

Question 14

14. Of what material do our favorite pteropods make their shells?

Answer 14

Argonite

Question 15

15. Which of the following plankton do NOT make their shells from CaCO3: pteropods, coccolithophores, foraminifera, diatoms

Answer 15

Diatoms- they have silica shells

Question 16

16. Name a couple of bio-processes that may be affected positively by rising CO2 levels, at least initially.

Answer 16

Nutrient cycles, food webs, increased diseases transmissions, invasion of tropical species, alters salinity,

Question 17

17. Rising CO2 levels could affect species differently in different life history stages. Why do you think many crustaceans, oysters, other molluscs, and echinoderms (sea urchins) can live OK, and sometimes even thrive, as adults in high CO2 conditions, and yet fail to reproduce?

Answer 17

CO2 impacts salinity and water temp. Most species have very specific conditions for reproduction.