I think humans are definitely on borrowed time. I would like to think that it isn’t too late though. Would reducing human population turn things around? Yes it probably would, particularly if you combined population reduction with a more responsible attitude towards animal habitats, overfishing, etc.

It would certainly help if more people shifted to plant-based diets. Even eating less meat would help. Apart from anything else, it would show a greater level of respect for animals and their habitats.