In my country, with 1.2 billion population, poverty and illiteracy plays in big role in population growth.
Sure, there is a considerable % of people who aren't aware of various birth control processes and options that is available out there.
And for many people who live below poverty, sex is the only good thing or entertaiment they experience in their life time.
That said, it also has a lot to do with the culture. India is very family-oriented culture based on various joint family concepts.
For most, having no children (or even one) is not an accepted or a desired lifestyle. As it stands with my generation, we are pretty standarized to two children per family concept.
That said, India is one of the places where you witness extreme adaption. Resources are horribly short!!
System is not perfect, just like many other things. When we were kids, we would have 2 hours of rationed water supply.
We would fill our reservoirs and for any need for extra water meant having to walk few blocks to a community water boring-pump.
Just last year, I was at my uncles, and they do not have power supply for almost 8 hours through the day.
These things are just part of our lives. You would find the most innovative adaptive skills in Mumbai monsoon, it will blow your mind!
Humans are extremely adaptive! But, this whole thing is a vicious cycyle. The worse earth's climate gets, the more we dip into resources and the more we dip into resources, the worse we make everything.
We are slowly but surely changing the way we think and the way we live. As everything we will reach a tipping point and everything will start all over again.
I mean, except for few ice ages, Earth was ice-free, wasn't it?