Just for the avoidance of doubt - despite the wording of my response to Markos I have no doubt that BALPA are being much much more realistic than CAE

(Disclaimer: I'm also a BALPA member who has witnessed the carnage, including redundancies, this has caused at a major airline).

Last proper pilot shortage was 1987.
a marmoset with a cpl would have got a DEC then

no, that’s not true at all, said monkey would have required an ATPL for a DEC

Or a SCPL if the MTOW did not exceed 20MT.
900 hours as oppose to 1500 hours experience necessary.
Last issue date by UK CAA 3 December 1989. Valid for 5 years.

I always thought the "imminent pilot shortage" doomsday-predictions-that-never-really-materialize were pretty much orchestrated by manufacturers and airlines alike to have access to cheap labour.
I still think the same. BUT:

Since we can pretty much discount there WILL at least be 1 efficient vaccine, let's go with the 2024 "return to 2019 levels" scenario in terms of worldwide pax numbers. I believe markets such as european and US domestic short-haul will recover quicker though (summer 2022) despite not overly favorable macro conditions. Capacity will be there perhaps revenue will take a bit longer. Everyone wants to gain market share.

If most of the VLAs A380s, B747s and some of the older B777s etc. are decommissioned, it means to match the number of travelers you need roughly double the airframes (B787/A321XLR etc) or at least 1.5 the airplanes.

Assuming that is true that there was a relative shortage of EXPERIENCED flight deck crew in 2019, that means unless they all of the sudden go single pilot there will necessarily be an experienced airline pilot shortage between 2022 and 2023. Remember that it takes years to reach the necessary experience to become a Commander even a senior first officer and particularly when people are flying once a month these days they are not really accumulating experience. Also remember that people keep retiring (confinement does not stop aging) and fresh cadets out of school are not building meaningful hours.

Unfortunately, in Europe, I'm afraid most pilots will not manage to find alternative and successful careers outside aviation unless they had a previous education and experience and will pretty much be forced to return to flying.

That's how I see it.

While it's certainly true that recruitment for European, USA or whatever regional short-haul will start first, I see it as a case of mass exodus of long-haul pilots towards short-haul for the sake of returning to flying. In a situation where jobs are few and far between, a firm A320 job right now is way, way better than the possibility of an A350 job in another 1-2 years (spent doing what?). Hence, the true shortage of pilots with relevant experience will only start when long-haul picks up.

We now exactly the situation, and it's useless to add anything else.
Just a little consideration:
When the market picks up again, (maybe a day with a vaccine, with less restrictions / quarantines / lockdowns), the demand will require, of necessity, airplanes and crews.
How can an airline recover without flying ?
This will be gradually of course.
The today's leading low-cost companies are trying to conquer the globe, by expanding, even with empty planes, as an investment for the future, opening new bases and routes.
This strategy is definitely based on recovering earlier and better than the competitors, but in order to actualize it, again, pilots will be needed; so I assume we would not need to wait the "peak" again.
I'm absolutely not saying that there will be a shortage soon, but of course at least a gradual redistribution sooner than 2024, I guess.

Not a good time to learn to fly except for recreation. The market will return but it will take time. There is a green agenda at the heart of government. The airlines are the sacrificial lambs for this. The Ryanair / easy travel explosion in Europe has meant that access to the desirable hot spots in Europe is available to all and not just the apparent elite. The weak and ineffectual Boris is influenced by his girlfriend who has climate change at the top of the pile post covid. The airlines and air travel are the targets for all sorts of unscientific reasons. The lack of support and the continued empty airports back this up. Consequently and unfortunately it is unlikely that there will be normal pilot opportunities for some time. However despite the gloomy predictions I do believe that air travel will return at some point in the future to relative normality. There is certainly no foreseeable pilot shortage.

Valid point , well spotted !