Huh, speak for yourself? My generation is the one that is going to be dealing full force with this.

Oh, it'll be waaaay worse in 250 years - so just relax. You won't see the the FULL force of climate change (or NZ's efforts at cost-cutting ;) )

So you're not convinced by a heated atmosphere, disappearing glaciers, major loss of arctic and antarctic ice, increased and worsening cyclonic activity and sea level rise?? I wish I could walk around with my eyes closed, but perhaps I am as this is seriously off-topic!

Major loss of Arctic and Antarctic Ice? Not according to many authorities.... It makes my head spin - all the claims and counter claims...

Well that escalated quickly.

Going back to the OP, I wonder how many pax actually need a water bottle? Would a solution be to have them available on demand/at the back of cabin?

Water bottles
 

Does the koru lounge have canned water (still or soda) or plastic water bottles ?
(with Auckland include the strata lounge as that is also used by Airnz)

It sure did.

The bottom line: Any attempt to portray this as anything but cost-cutting 'sustainability theatre' is disingenuous to the real issues of sustainability and climate change. If Air NZ were ultra-concerned about the plastic, the bottles would be replaced with an alternative, and one that may actually cost more to implement, e.g. fully degradable bottles etc. But I think we all know that there is no way that is going to happen. At the same time, it is a business that is trying to stay profitable in a tricky environment (no pun), so two sides to everything.

All said and done, water is a basic need, and if I struggle in the future to have easy (instant) access to hydration when flying, due to some bizarrro attempt to cost save, that is a bad look for an airline whose premium cabins are not cheap to fly in. However you slice it, taking in-seat water sources away will blatantly deliver you less hydrated passengers on average.

Nobody needs to dehydrate. There's a call bell. Push it and ask for water. They also do a drinks run. Ask for a drink.

Taking your own water bottle is a viable solution. You can use it in cars, at work, the gym etc Why do I get the feeling the small effort is beyond some people?

It does need to be remembered that water is only being removed on short haul TT and Islands flights. Air NZ serve plenty of water on these flights particularly as the premium meal service in BP is ongoing for well over 1hr of a 3hr flight let alone the preflight and post takeoff drinks. I don't agree with this move, but to suggest people will be dehydrated is frankly a bit of a stretch.

I often drink 2-3 bottles at least on overnight on long haul flights so if they got rid of those and I had to get up or call a crew member to come and fill a bottle it would be a real pain.

I wouldn't be too surprised to see people drinking less of the water and instead drinking more beer and / or wine. This could easily offset the cost savings.

Don't be surprised when they announce they're switching to cask wine to save weight as an environmental initiative ;)