The International Air Transport Association (IATA) has set the following goals for the aviation industry with respect to GHG emissions:

A cap on net aviation CO2 emissions from 2020 (carbon-neutral growth)

A reduction in net aviation CO2 emissions of 50% by 2050, relative to 2005 level.

Based on the research findings in Lu (2018), what action (or combination of actions) from the list below would you recommend encouraging reductions in GHG emissions through the use of biofuel in aviation?

Taxation of airline passengers (per passenger tax).

Taxation of jet-A1 (oil-based) fuel.

Subsidization of biodiesel production

Carbon offset by airlines (cap and trade)

Government legislation/regulation of biofuel content /litre

All the information is given, please show explanation for recommendation.