Carbon Cycle Session

How much CO2 is sequestered by the biological carbon pump each year?

• 20 Gt

• 30 Gt

• 40 Gt

• 50 Gt

Mature forest trees in the UK contain how much carbon per hectare?

• 170-200 tonnes per ha

• 150-170 tonnes per ha

• 200-220 tonnes per ha

• 220-250 tonnes per ha

Permafrost containes _____ Gt of carbon.

• 1400

• 1600

• 1800

• 2000

What is the typical residence time for carbon stored in the lithospere?

• 20 million years

• 50 million years

• 100 million years

• 150 million years

Colder ocean temperatures _________ the solubility of carbon.

• increase

• decrease

Which is not part of an example of a positive feedback loop?

• More carbon leading to higher temperatures leading to increased plant growth

• More carbon leading to ocean acidification leading to less phytoplankton

• Increase in temperature leading to less ice leading to a decrease in albedo

• Increase in temperature leading to more evaporation leading to more water vapour

Soya farming has a carbon biomass of ______ tonnes per hectare

• 2.7

• 3.6

• 4.1

• 1.5

Ho much carbon in total (above and below ground) do rainforest trees store?

• 180 tonnes per ha

• 220 tonnes per ha

• 260 tonnes per ha

• 280 tonnes per ha

Carbon dioxide levels have increased from 180ppm to ___ppm since 1750.

The carbon cycle is a/an __________ system.

• open

• closed