I'm not particularly interested in getting into pointless debates with climate science deniers any more. The evidence is clear, very widely available, and the ambiguity is all in the detail, not the big picture. Look at NASA, IPCC, a bunch of textbooks that are readily available, from the (actually very good)
, up to multiple volumes that require multiple degrees to properly understand.
However there are aspects of the public picture that are less accurate, particularly with regard to aviation. So here's a few points about why this is often misunderstood, or just why we need to worry.
Aviation is presently responsible for between 2 and 3% of global CO2 emissions. That's reasonably trivial. We're also as an industry reducing our per passenger mile emissions by about 2% per year, through a combination of technological and efficiency improvements. So that makes it seem even more trivial. Now to the bad news.
Aviation is (a) totally reliant at the moment on liquid hydrocarbon fuels, (b) growing globally about 5% per year, (c) emitting other things, not just CO2. In particular the latest science says that contrails are contributing to radiative forcing: the physical mechanism behind global warming, to a factor of about double what our CO2 emissions are doing.
Now, electric flight is one way in which we can tackle both CO2 and non-CO2 emissions, and if we can crack it the reliance upon dwindling supplies of fossil fuels. Unfortunately it also is spectacularly inefficient and difficult to achieve, as evidenced by the fact that in 119 years of powered flight, we so far have one (count them) certified electric aircraft in the world - capable of about an hour full to flat, and a payload of one pilot and one passenger. This suggests that pursuing this technology may be totally pointless.
Except it isn't, for a bunch of reasons. A lot of the potential future technologies needed involve electric propulsion, even if not the current battery-inverter-motor-thrust combo. There's hybrid combinations, fuel cell technologies (hydrogen's the favourite, but I've been to enough meetings discussing ammonia that may be part of our future). So the present work on electric flight is, in my opinion, an absolutely essential step towards eventual technologies that *will* have a significant impact on allowing aviation to continue to grow as an industry, whilst reducing both our CO2 and non CO2 emissions.
But, none of this actually says that the present generation of electric aircraft are useful. They may find some tiny, economically and environmentally insignificant niches. But what they will do is teach us a whole bunch of lessons we need to genuinely move forward and start - very necessarily - reducing our emissions.
There are other technologies that might do the same job. eFuels - using renewable energy to extract CO2 from the atmosphere and reconstitute it into synthetic jet fuel. Hydrogen combustion. (Oh, by the way we're also very reliant here on a bunch of work from the chemical engineering industries also - whether that's to produce green hydrogen, green ammonia, or sustainable synthetic jet fuel. But they are working very hard on that.) But we can't afford against the urgency of climate change to pick winners - we need to pursue everything right now, and let natural selection determine the technological winners.
If we don't, denying climate science won't be an option - we will see externally imposed demand control that will decimate our industry.
G