The question is for the industry what will replace hydrocarbon fuel?
Whilst the present emissions are only 3% by mid century, aviation will account for approximately 30%.
With forecast growth in ASK at 5% per annum the CO2 net emission cap is loaded with assumptions of questionable robustness. For aviation to be carbon neutral from 2020, efficiency gains will need to be found every year at rates that largely map the improvements in jet engine technology since the 1960's. Further, embedded in the assumptions are gains best described as "Rumsfeldian", unknown-unknowns: As yet undetermined efficiency gains will continue to be invented. Whilst substitute fuel sources are big on media and technically feasible, they are not commercially viable,
By way of an example, Bio Fuel technically works, the problem remains the scale of agricultural land needed to support 1/3 of the requirements in a country like the USA, would result in reduced food production of major cereal crops..
By way of contrast, the maritime industry already taxes sulfur levels, is transitioning away from fossil fuels and will by 2075, be completely free of hydrocarbon based fuel. The aviation industry has no such viable alternative.
It is possible that the industry becomes a much larger emitter both in gross terms and in percentage derived from aviation, than even the optimistic forecasts suggest.
IFF the world decides that 'CO2 emitters are a problem', then the airline's industry as a collective may face a public relations problem, which could arguably mutate into something more concerning: a reduction in available air transport options.
This is neither in defence of, nor rebuttal of climate change.
Last edited by Rated De; 22nd May 2019 at 12:00.