The UK spent a shit-tonne on two new aircraft carriers, of which only one will ever be used and then had to stump up another shit-tonne for the planes to fly off them/it, which are more expensive than they could be because of the compromises of the carrier platform. Then, a third shit-tonne later, they have a reduced number of air defence ships that keep breaking down in warm water requiring shit-tonnes of money to fix.
Anyway, enough ranting about the Navy, I’m out of that fight now, so it’s not fair to get into it again.
Suffice to say defence spending is a huge money-spinner for the contractors providing the materiel and support. They know countries will pay, so they can do what the hell they want. It’s not their fault, they are just corporations doing what business does. They are just in a market where the people with the requirements are making decisions have no idea of what ‘value for money’ is.
So, climate change… Armies, navies, air forces need to exercise, if you don’t train, you can’t fight effectively and the defence of the realm is the number one priority of any government. Training takes fuel and the machines that are used are not chosen for their economy. Take a Landrover. It’s never been the most efficient thing in the world, but slap some basic armour on it, add a weapons mount kit and suddenly it’s into single figure mpg. The further you fight/train away from your supply bases, the more you need to transfer supplies to them, taking fuel, water, etc. It’s a vicious circle.
Trying to reduce CO2 in that is tough. You can reduce training, but that reduces your army’s effectiveness, makes your pilots worse. In war, it means you move less and sacrifice initiative.