ENVS CHAP 12

Question 1

What is a carbon source?

Answer 1

Something that releases carbon into the atmosphere. Fossil fuel burning is the main source of CO2 release as it is responsible for more than 90% of the total flux. Deforestation, wood burning, respiration and decomposition of dead biomass/OM is also a source of CO2

Question 2

What is a carbon sink?

Answer 2

It is a site of storage of carbon. The ocean and terrestrial CO2 sinks are relatively equal in storage capabilities and are critical in reducing fossil fuel combustion. There’s lots of uncertainty with how much terrestrial sinks can hold, but ocean sinks are known with high precision

Question 3

What is radiative forcing?

Answer 3

It is the imbalance between incoming solar radiation and outgoing infrared radiation. It expresses a change in energy in the atmosphere due to GHGs.

ex. CO2 increases warming while some aerosols reflect back light and can reduce warming

Question 4

How do methane sinks work?

Answer 4

They alter methane to other compounds so it less destructive.

ex. biggest method is atmospheric photooxidation, which oxidizes methane into CO2 and H2O

Question 5

What is residence time?

Answer 5

It is the amount of time a molecule/gas stays in the same place, usually referring to the atmosphere

ex. CH4’s atmospheric residence time is 12 yrs opposed to 100yrs for CO2

Question 6

What is methanogenesis?

Answer 6

It is the production of methane by bacteria in the absence of O2. Decomposers use O2 to break down dead OM and produce CO2, but in anaerobic conditions, CH4 produced instead