Then again such approaches to the problems facing human civilisation are complete tosh. Baloney.
Western middle-class and "biological", rather than world proletarian, Marxist and socialist revolutionary.
Far too close to neo-Malthusian arguments that treat human beings like fruit flies in a jam jar and generally stink of fascism, rather than solving the problem that really confronts people - the need to overthrow the wasteful and destructive system run by the greedy monopoly-capitalist ruling class.
Designed to get eco-warriors' pants in a twist, rather than convince people of the need for rational, Marxist-Leninist revolution.
In the short term, the human population NEEDS TO GROW for the fight to overthrow the monopoly-capitalist economic system that is spreading poverty and destruction because of its "over-production" crisis (see Marx's Capital Vol III, and Lenin's Imperialism the Highest Stage of Capitalism) and threatens the world with nuclear war.
The struggles of the poor to raise families on a mass scale around the world drive "liberal" types like David Attenborough MAD. Being as Establishment as you can get, he simply cannot face the understanding that the Western parliamentary democratic system is the "freedom and democracy" cover for rampant global profiteering destruction and warmongering that has to be overthrown by communist revolution.
Far simpler to say as he does in BBC TV programmes "WE are destroying the planet", "WE are poisoning the oceans" etc. NO! It's the CAPITALIST PROFIT MOTIVE with its exploitation, consumerism, waste and warmongering that is damaging and destroying the planet.
Even revisionist-led and capitalism-using China, run by the Chinese CP and using central planning, is bringing in environmental policies that will start to show up surrounding capitalist wastefulness and callousness towards the world's health and safety.
China is, of course, building hundreds of huge cities and aping the West a bit too much in its development, but it is reformable, and the bigger socialist revolution around the world has no reason to end up in any antagonistic relationship with the People's Republic.
But there can be nothing but CONFLICT between the world's population and the warmongering degeneration of the US Empire and the other imperialist countries. Two decades of the "war on terror" and "regime change for rogue states" are nothing but the harbinger of worse and worse destruction set to be inflicted on oppressed countries and - sooner or later - to be inflicted on France, Germany, Japan, Brazil, India or Russia in inter-imperialist shooting war (after WW1 & WW2).
The world does not want to end in smoking ruins so the world's proletariat will defeat and overthrow ALL imperialism (as opportunities arise, bit by bit).
Then we can get on and build rational, scientific socialism and do our best to look after the planet. Including reining in damaging over-consumption (which often alienates and damages us because of its envy-inducing and selfish characteristics). All economic growth can then be for a rational purpose, rather than for the sake of commodity production.
Jetting off to "get away from it all" will ease off as a mantra too. If everyone is involved in interesting and valuable work, and holidays with good friends in nice local resorts are available, what's the desperate need to "get away"??
Technology can be dedicated to being clean and green. Human ingenuity will find clean and green replacements for the damaging use of fossil fuels and jet fuels.
With socialist civilisation in place, any given country's population will eventually grow less rapidly and stabilise in size at a fairly reasonable rate, given civilised development prospects and an end to poverty, war, drought, famine, disease etc.
Don't get me wrong: there is nothing wrong about endeavouring to shift all civilised thinking and action towards care for the environment. But the Marxist truth about the global threats and realities of monopoly-capitalism has to be faced.
And people have to reject the middle-class, neo-Malthusian arguments that stink of forced sterilisation, mass murder and inhuman eugenics.
Build Leninism. See epsr.org.uk