The island where we are living now recently saw an intensive trap and neuter program for the feral cat population and it has made quite a difference. These two cats are probably going to be the last pets we ‘own’ and the plastic carriers will be donated to a shelter when we don’t need them anymore.

As much as I abhor plastic in general, I’m a fan of plastic cat carriers like the ones shown in your picture. A carrier like that is a godsend when evacuating on foot during a storm, because the solid top keeps the cat relatively dry. The carriers are also stackable if transporting several cats by car or spending time in a crowded evacuation shelter. The solid tops and bottoms of the carriers keep each cat in the stack from being subjected to urine from those above or teeth or claws from those both above and below.

If having plastic carriers troubles your conscience, you could sell them to someone else who will soon be traveling. I have often seen people who are about to fly with their dogs ask if anyone has a used airline crate for sale, and imagine that a similar market exists for cat carriers approved by airlines. However, in your shoes I would save the carriers for the next time you move internationally.