L2 - Climate crash course

Question 1

Which are the important anthropogenic GHG and their procentual amount?

Answer 1

• CO2 75%
• Methane Ch4 16%
• Nitrous oxide N2O 8%
• Flourinated gases 1%

Question 2

Why is the CO2 concentration raise cyclic?

Answer 2

Levels of carbon dioxide in the atmosphere rise and fall each year as plants, through photosynthesis and respiration, take up the gas in spring and summer, and release it in fall and winter.

Question 3

What are the uncertainties with the climate sensitivity and the effect on climate change of aerosols?

Answer 3

• How much will temperature increase for a doubling of atmospheric CO2concentration (at equilibrium)?

Aerosols have a net cooling effect and hide some of the warming signal from CO2emissions –but how much?
•most aerosols cool by reflecting sunlight (but black carbon i.e. soot also warms by absorbing sunlight and reducing albedo on snow)
•complex interactions with clouds
•both natural and anthropogenic sources (volcanos & fuel combustion)

Question 4

What is climate sensitivity? What is likely to happen with and without feedbacks?

Answer 4

Climate sensitivity is a measure of how much the Earth’s climate will cool or warm after a change in the climate system, such as how much it will warm for doubling in carbon dioxide (CO. 2) concentrations

Without feedback —-> about 1.1 C per doubling of CO2 concentration

Question 5

What is BECCS?

Answer 5

Bioenergy with carbon capture and storage (BECCS) is the process of extracting bioenergy from biomass and capturing and storing the carbon, thereby removing it from the atmosphere.