Does anyone have any idea why CO2 levels would spike so high when a plane takes off?
787 maintain internal air pressure equivalent to 6,000 feet of elevation. All other commercial aircraft maintain 8,000 feet air pressure. I think most of my discomfort from long flights is due to altitude sickness. The only time I have slept on a long flight and awakened refreshed was on a 787.
Jet engines use a neuro-toxic lubricant. Occasionally, some of this enters the cabin through the compressed air feed and poisons the passengers [1]. 787 passengers don't have this risk because the planes don't draw air from engines.
[0] https://en.wikipedia.org/wiki/Boeing_787_Dreamliner#Interior
I'd bet if you can get a few popular newspapers to write articles about this with scary headlines ('Airline nearly suffocates passengers - and doesn't even apologize!'), then airlines will remind pilots not to do that...
That seems like quite a long time to ignore an obvious item on the flight checklist.
Seems unlikely. Actual altitude sickness is generally considered to occur only above 8000 ft, and above 10000 ft is where the real risk begins. Symptoms generally don't appear until 12-24 hours after climbing to altitude. Also, risk of altitude sickness increases with physical exertion, and you're probably not doing much of that on a plane!
CO2 rises in the cabin during taxi because the bleed air system is not effective while the aircraft is moving slowly. This is another good feature of the 787: cabin air conditioning works adequately even with the aircraft at rest.
Presumably the external air mix is just full of exhaust before they're at speed.