Originally Posted by
hfly
The aviation industry has consistently been moving toward cleaner and more efficient planes.
If you philosophically accept individual moral culpability for large scale problems, then creating 15 tons of carbon emissions for a roundtrip flight in first class that you could have potentially done in business (or even economy), consolidated into other travel, or skipped entirely is difficult to defend.
If we're aiming for 1.5 degrees C of total warming, aviation is about 25% of the total budget because we now have a clear technological path to rapid decarbonization of terrestrial power systems, automotive transit, etc. Please note, this is for the integral of the time-period between now and 2050. In the year 2050 itself, aviation would essentially be close to half the world's emissions if the IATAs predictions for passenger growth are accurate. To say this is a rounding error is totally illogical.
Similarly, only a small portion of the world actually has the privilege of boarding a plane in a given year. Conversely, a huge portion benefits from international trade and the built environment that necessitates concrete. If I had to give up aviation, the city I live in, or international trade, I would choose aviation in a heart-beat. I don't deny the importance of reducing carbon intensity of concrete or shipping, but fuel expenditures via aviation are the things which I have most direct control over and can most easily reduce. Finally, aviation is something we all probably have a passion for given our participation in this forum.
https://www.carbonbrief.org/aviation...-carbon-budget
If we were still using 60's - 80's era aircraft, the aviation industry would be producing 15-20% of the World's CO2 emissions, not 2%
Unfortunately your numbers are totally wrong. A 777-200 (about halfway through its useful commercial life) has about 65% of the per-passenger-mile fuel consumption of a 747-100, not 10-15% as suggested by your post.
https://www.transportenvironment.org...efficiency.pdf
(figure 1, filled black squares)
Furthermore, the 787 and A350 likely reflect close to the limits of future improvements in the composite airplane and high-bypass turbofan model. We're going to need major technological advancements (alternative power systems) to achieve further substantial advancements. The pathway of technological development is not an immutable force gifted to us by the gods, our economy must choose what to invest in, and the steps outlined in this thread are aimed at increasing the economic pressures and clarifying the technical decision making in favor of major advancements in aviation technology.
Let's talk about the shipping industry, which uses "BUNKER" which is the cheapest dirtiest fuel that you can imagine
Impressive commitment to argument through, "whataboutism," here. However, apparently ill-informed regarding the January 1, 2020 deadline for reducing sulfur contents 7-fold compared to current limits:
https://www.shell.com/business-custo.../imo-2020.html
Furthermore, any technological advancements made in non-fossil fuel aviation power-systems is likely applicable to the marine sector as they're both applications of the same problem: developing energy-dense energy storage systems. Pushing aviation to be more efficient also helps address marine emissions.
Finally, an excellent technical primer for anyone interested on carbon emissions related to cement:
https://cleantechnica.com/2019/11/26...-economically/
With enough cheap renewable electricity, we could easily address about half of cement's emissions related to heating, but the part that comes directly from transforming the limestone is a very difficult problem without carbon sequestration, etc.