It was interesting that you mentioned Red Mars (by Kim Stanley Robinson) since there are some controversial ideas around population and birth control in his novels.
People are already living longer due to advances in technology and that trend will continue to put pressure on our precious resources.

Farming (as we know it today) is one of the areas that will see the biggest change.

We must get use to the idea that meat will be 'grown' in laboratories!
'Alternative' sources of protein will also become part of our diet...
Fresh food production will continue to move closer to cities by implementing vertical farming.

The plus side for us (working with and/or interested in data) is that there will be many opportunities for IIoT, Big Data, Machine Learning and AI projects.