Changes, certainly. End of humanity, maybe not. Deserts will expand as the world gets warmer. But this still leaves us a lot of living room. Lots of factors at work by the end of the 21st century. Robotics can work in environments with no water.
Children born after 2020 will certainly see changes as previous generations did. But an end? No.
Boy are you pessimistic, potential end of society by 2020?
Did I imply the end of the world by 2020?
I think those born after 2020 will see the deserts expanding beyond current borders in their life times, assuming the warming trend continues. People living in deserts will die out or move to cities outside the desert.
On desert formation, especially in Africa; subsistence existence with charcoal and wood as primary fuels has resulted in HUGE deforestation in the northern reaches of Africa.
In other words, end of society as we know it.
This is sort of a given, in the past 100 years, take any decade´s society as they knew it, and
one will find that it has ended. So what else is new.