Perhaps aviation biggest challenge....
 

Journo by any chance?

Journalists and "consultants" who believe that they are the ultimate authority when something goes wrong

Realistically, that's not setting the bar very high ...

With aviation accounting for about 2% of all global emissions and road transport for 74% - our biggest challenge is to inform and educate.

What type of aircraft is a B373-800 ?

New name for the MAX?!

I think the biggest challenge facing aviation and every other "climate-destroying" industry and activity is that the "tree-huggers" can't see anything other than a "ban it" approach. The eventual solution will undoubtedly have to come from an engineering source, using technology to remove the carbon we have poured into the atmosphere over the last 250 years.
There has been some very promising progress on possible techniques in Canada recently, and Cambridge University have set up a dedicated department looking at possibilities, but the activists still think that stopping everything now is a viable position, and that is taking a lot of attention (and resources) away from a realistic approach to the problem.
There will undoubtedly have to be elimination of the worst polluters - burning lignite to produce electricity to charge electric cars makes absolutely no sense at all - but for many human activities the ultimate solution will probably be to find ways to effectively remove the pollution post-event rather than to stop the activity completely.

Yes, there are lots of activities to reduce greenhouse gas emissions, converting traditional mechanical, hydraulic and pneumatic systems with electrical alternatives. Electric brakes and thrust reversers are just two examples of the work being done, reducing weight and eradicating the use of corrosive, inflammable fluids. The 'More Electric Aircraft' brings its own challenges with increased voltage and power levels which has to be managed through the aircraft wiring. Higher dependency on insulation materials and the continual need to reduce weight is a real focus for the R&D teams at Airbus, Boeing, etc. I'm working on some of these challenges today and great steps are already being taken to meet these growing needs. I'm not employed by Safran but here's a short article that shows their commitment to these initiatives.

https://www.safran-electrical-power....t-power-future

If you must worry about CO2 rather than fuel cost.
Take aircraft type, normal fuel burn for flight, divide by number of miles flown, divide by number of revenue pax. Most modern twins will return better than 120mpg per revenue passenger.
No infrastructure is needed to be built and maintained between departure and destination - no rails or tarmac
Other 'incidentals'
Cost of passenger time traveling is also reduced.
Some journeys are only practicable by air.

Some journeys are only practicable by air.

But as they used to say, is your journey really neccessary? e.g. stag weekends to las vegas as some work colleagues recently did?

Yes, and this will have unintended consequences. When I learned to fly (I think back around when A & C was filling up a Trident) there were basically two types of pilots applying to fly for the airlines: Former military pilots, and pilots emerging from "private aviation". The ex Military pilots were very well trained, and used to flying within a regimented system. The private pilots had a more self directed learning path, in more simple planes, as generally they had funded their training and experience themselves. Now we have those paths, plus the more formalized career training path, which really does not include much "private" flying. Fewer hours, less total experience, training directed at the airline role only. Perhaps more similar to the military training environment than than private path.

The "private" path has one difference to the military or career path training, being a lot more self directed, with the pilot making more of their own decisions (particularly go - no go), and solo flying - perhaps in a modest "experience builder" plane. I have seen that pilots who emerge from the self directed path, and have flown a lot of solo, are confident decision makers. The airline passengers of the future would like to be flown by pilots who are well motivated, and confident decision makers. That's not to speak less well of military or career path pilots, we need a mixture of all types of pilots.

As private flying becomes more costly, and less socially welcome, the opportunity will be lost for new pilots to fly hundreds of hours of personal experience building, and solo decision making. Airliners will be flown (or watched form the pilot's seat) by pilots who have passed the training to the minimum requirements, and perhaps had little opportunity to make solo piloting decisions, and carry out the outcome of their decisions.

I hope that the career path training ramps up to produce very experienced entry level airline pilots, 'cause they won't be coming from the "private" path so much in the future.....

It is refreshing to see some science being applied to the issue as opposed to believing that school children egged on by pushy parents are the world experts

Aviation is 4% of UK CO2 production, and 2% globally. Both aviation and shipping have applied science to reduce pollution per unit cargo mile, but volumes have increased. Banning transportation will not solve anything.

The biggest issues are:

The big polluters. China produces 100 times the CO2 that the UK does and has increased by 17% ie one other country has increased CO2 production by 17 times the total UK CO2.

Developing countries particularly Poland and Indonesia who are churning out coal, building coal fired power stations and refuse to come to the table

Corruption, which has led to deforestation especially in South America and mass poverty in sub saharan Africa. The latter perpetuates wood burning for fuel and prevents eg hydroelectric development in the DRC

The west IMHO needs to address these ongoing issues and promote technology such as carbon capture to sell / give to to developing countries.

Just in case you have been off-planet for the last 100 years or so:
Greenhouse gasses
It was an established module on my engineering course over 40 years ago