Fundamentally, some object to the initial premise that, as Phil Harding puts it, we are living beyond the 'carrying capacity' of the planet. Technological advances and a fairer distribution of resources mean the idea of a finite world is questionable, they argue. 'Absurd', even, says Julian Baggini, editor of The Philosophers' Magazine. 'Clearly there's an absolute limit somewhere, which despite all our efforts couldn't sustain that population, but the idea that's coming soon is rather dubious, to say the least.'
The latter quote reads fine to me.
Most credible moralities say we have to take into consideration the interests of anyone who might be affected; that's certainly the case whether [or not] they are geographically close; it should be the case whether they are temporally close to you or not.