If you see multiple indicators that rapid and increasing population growth is assured as a sign that 'the world is getting better', I fear for our future.
The UN predicts that the population will stabilize between 11 and 12 billion around 2100. That is much more than today which poses a large challenge, but not an insurmountable one.
How population affects climate change seems to be the biggest negative externality.
Of the 600 marine fish stocks monitored by FAO:
3% are underexploited
20% are moderately exploited
52% are fully exploited
17% are overexploited
7% are depleted
1% are recovering from depletion
Further troubles exist on land, with global deforestation increasing YOY.
How will more people living longer benefit from these factors?