The population of the planet has grown from (approximately) one billion maximum, through most of world history; up to (apparently) more than seven billion at present - and this has happened since the industrial revolution and mostly in the past century.
http://charltonteaching.blogspot.co.uk/2014/02/the-modern-world-is-selecting-for-pure.html
Six billion of the population are therefore sustained by the global system of technology, organisation and trade that we call Western Civilisation - and thus includes all of the 'third world/ developing' nations where population growth is so rapid.
For example, without Western civilisation (including medicine and public health) Africa would have less than a tenth of current population.
And of course Western Civilisation is going to end, and probably quite soon - for many, many reasons not least of which is that the majority of the world, including the global establishment, are extremely hostile to it - and to that which created and sustained it.
This means that billions of people will almost-certainly die, quite soon - although exactly how many billions and how rapidly is merely a question of how long the shrinking remnant can live-off accumulated, but also shrinking, capital stores.
However; 'civilisation' is (quite rightly) nobody's priority to sustain - not least because it is a by-product rather than a strategy; and is anyway a very long-term and remote problem - so it will always be made a low priority in competition with so many others.
The big question is not If there will be a collapse of technology and trade and a colossal extinction event; but why it has not already happened - given the malign intentions of the most powerful people in the world.
The answer is simple, albeit ominous.
The Global Establishment is - grudgingly - maintaining the international system of trade and technology because they are engaged in spiritual warfare, and they are currently winning.
In a nutshell, the Global Establishment are ultimately tools of the supernatural powers of evil - and because evil is winning more and more souls to self-damnation, they want the system to continue... at least for a while longer.
Think of it this way: Billions are going to die for sure - but what is in doubt is the fate of these souls: will they accept the salvation offered by Christ, or will they choose to reject this gift and instead opt for damnation?
Everything currently indicates that more and more people (most obviously in the West - where moral inversion is official and dominant; but seemingly almost everywhere else too - by their behaviour) are motivated by fear, resentment, pride and despair.
In such a state of conviction, the mass of post-mortem souls will not want Heaven, will purposively reject salvation... Certainly they won't want it at the necessary and inevitable price of personal repentance and faith (including admitting they had been fundamentally wrong in mortal life, and then actively joining with God's eternal plan for our deification).
What this suggests is that it is only the wickedness of the world which is keeping it going, and postponing the billion-fold die-off; and if there are strong signs of a Christian awakening in the hearts of Men, then that will be the time that the demons pull-the-plug on the vast, multiply-interdependent and therefore exquisitely fragile system that we call the global economy.
The mass death will come sooner or later, whatever happens - because its causes are probably unstoppable but in any case not being stopped - yet it may perhaps come sooner if many people do the right thing, than if they don't.
In which case there may be a stark choice between either extending this-world survival coupled with the expectation of an increased rate of eternal damnation; or alternatively accepting rapid collapse and death as the cost of saving more souls for eternal happiness...