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1. Over the glacial-interglacial cycles of the past 800,000 years, temperature i

ID: 291262 • Letter: 1

Question

1.

Over the glacial-interglacial cycles of the past 800,000 years, temperature increases occurred before CO2 changes. This suggests:

CO2 is not the main driver/forcing for glacial-interglacial changes

Temperature responses are due to forcing from orbital cycles

Positive feedbacks are necessary to continue warming and cooling trends

All of the above

None of the above

2.  

Which feedback did NOT amplify the orbital forcing that starts glacials?

Weathering feedback

Ice-Albedo feedback

Water vapor feedback

Carbon solubility feedback

3.  

In which of these cases could we stimulate phytoplankton growth by adding a nutrient which is limited?

C:N:P = 106:16:1

C:N:P = 53:8:0.5

C:N:P = 212:20:2

C:N:P = 212:32:2

3.  

Low-level clouds tend to ______ Earth by ______.

Cool / reflecting sunlight

Cool / trapping heat

Warm / reflecting sunlight

Warm / trapping heat

5.  

High-level clouds tend to ______ Earth by ______.

Cool / reflecting sunlight

Cool / trapping heat

Warm / reflecting sunlight

Warm / trapping heat

Reflective clouds lead to more climate cooling when _____________. The figure accompanying this question shows the % of sunlight reflected by different parts of the Earth system.

they form over oceans because oceans have a much lower albedo than clouds

they form over oceans because oceans have a much higher albedo than clouds

they form over tropical land because tropical land has a higher albedo than clouds

A

CO2 is not the main driver/forcing for glacial-interglacial changes

B

Temperature responses are due to forcing from orbital cycles

C

Positive feedbacks are necessary to continue warming and cooling trends

D

All of the above

E

None of the above

100 90 80 SNOW fresh CUMULUS STRATUS 70 60 SNOW old ALTOSTRATUS CIRRUS 50 STRATUS SAND ICE 30 SOIL DESERT SAND dry wet CROPS 20 SAVANNA twvATERISOLI FOREST TER Iwou|FOREST 1MEADow 10 ? WATER wet. TFOREST

Explanation / Answer

1A

CO2 is not the main driver/forcing for glacial-interglacial changes

2. B Weathering feedback

3. C C:N:P = 212:20:2

4. C Warm / reflecting sunlight

5 . D Warm / trapping heat

6 . A they form over oceans because oceans have a much lower albedo than clouds

CO2 is not the main driver/forcing for glacial-interglacial changes