I'll add one more...
e. The environment, like it or not, is an economic commodity, even more so in less developed parts of the world. If conservation is to succeed, it needs support in terms of tourist pounds, dollars or euros ...and that means flying. Drive down the numbers flying and some of these schemes will fail. A couple of simple examples - if Bharatpur in India is to see policy change (and it appears it might), it will only because of the direct imortance of tourism. All the African national parks, the finest wildlife areas on the planet, how safe are they without visiting tourists?
Fly and save the planet, cut your carbon footprint and see it screwed beyond repair! And as they screw it, and the animals cry as their home is gone, watch too as the trees get burnt, pumping yet more of that grubby carbon stuff into the air!