Imagine that we had the population we have today, but we didn't have our technological societies. Would there be more or less pollution and environmental degradation?
IMO, the Green movement is trying to impose a certain viewpoint on humanity, seeking to demonise, even criminalise, those who question it. One only has to look at how it operates in influencing governments. Prominent green spokespeople who want to tax the hell out of people typically jet-set all over the world and are more rather than less profligate than average folk who are just trying to survive from day to day. It's a movement led by liars and hypocrites, but unfortunately, many well-meaning sympathisers just can't see it.
Why wouldn't they insist that their conferences use as little resource as possible - minimal food, no alcohol, and no heating or air conditioning? Hold them in slums to make all delegates more aware of the issues involved?