Lecture 8

Question 1

Anthropogenic emissions:

Answer 1

emissions of GHGs, precursors of GHGs and aerosols caused by human activities.

Question 2

Anthropogenic removals:

Answer 2

biological sinks of CO2 and chemical engineering to achieve long-term removal and storage.

Question 3

Climate neutrality:

Answer 3

concept of a state in which human activities result in no net effect on the climate system.

Question 4

Net zero emissions:

Answer 4

anthropogenic emissions of greenhouse gases to the atmosphere are balanced by anthropogenic removals over a specified period.

Question 5

Technological improvements are:

Answer 5

Electrifeid powertrains and propulsion system, hydrogen fuiled aircraft, energy-efficient aircraft configurations

Question 6

Electrification disadvantages:

Answer 6

Very heavy so a low energy density so not feasible for large and long range aircraft beceause they are energy intensive.

Question 7

Hydrogen advantages:

Answer 7

Lack of any in-flight CO2 emission, high energy-to-mass ratio

Question 8

Hydrogen disadvantages:

Answer 8

Larger emission of water vapour, more formation of contrails, hydrogen fuel tanks are very heavy.

Question 9

Contrails

Answer 9

are water vapour that condenses as ice onto soot particles and trap and absorb outgoing heat which otherwise escapes into space.

Question 10

Drop in fuel:

Answer 10

fuels compatible with current aircraft and which can be blended with conventional jet fuel

Question 11

Non-drop in fuel:

Answer 11

Fuels that require substantial changes to the aircraft in combination with new infrastructure, liquid hydrogen and methane

Question 12

Sustainable Aviation Fuel (SAF):

Answer 12

a biofuel with similar properties to conventional jet fuel but with a smaller carbon footprint, can reduce life cycle GHG emissions dramatically compared to conventional jet fuel

Question 13

Impact on airports

Answer 13

See slides.