Everyone who cares about healthy life extension should also have a basic understanding and an interest in planetary scale ecology. Our future must be sustainable or there is no future, that much we know.
A few papers on this topic:
Nature. 2009 Sep 24;461(7263):472-5. doi: 10.1038/461472a.
A safe operating space for humanity.
Rockström J, Steffen W, Noone K, Persson A, Chapin FS 3rd, Lambin EF, Lenton TM, Scheffer M, Folke C, Schellnhuber HJ, Nykvist B, de Wit CA, Hughes T, van der Leeuw S, Rodhe H, Sörlin S, Snyder PK, Costanza R, Svedin U, Falkenmark M, Karlberg L, Corell RW, Fabry VJ, Hansen J, Walker B, Liverman D, Richardson K, Crutzen P, Foley JA.
Rockström, Johan, et al. "Planetary boundaries: exploring the safe operating space for humanity." Ecology and society 14.2 (2009).
Science. 2012 Sep 21;337(6101):1458-9.
Ecology. A measurable planetary boundary for the biosphere.