The trend suggests we actually need longevity to survive as a species. Studies show an increase in quality of life decreases our fertility rate, and the world is on a trend to dip below sustainability within a generation. Forget those that scream overpopulation, it's foolish to look at our raw population surpassing 7 billion and suggesting runaway growth.
Bonus thought, when we dramatically increase our longevity and quality of life we could end up as some race mostly composed of thousand+ year old elders who rarely breed. Which in all honesty is better for the universe, greater chance of other species thriving and joining us.
Info and extra reading: The rate of sustainability for developed societies is 2.1 kids, today we have Australia at 1.92, US at 1.9 and UK is 1.94 (wiki: http://en.wikipedia.org/wiki/Total_fertility_rate#Replacement_rates)