Oxford Dictionary definition: Sustain* ~ Enable to last out…
The pressure of population on the environment is not a new concern, by any means:
In his book, Paul Ehrlich argued that increasing populations and affluence were placing growing pressure on the global environment in many fields, from loss of biodiversity, overfishing, global warming, urbanization, chemical pollution, and competition for raw materials. Ehrlich and others, now argue that whilst the projected timing was wrong, humanity has simply deferred the moment of disaster through the intensive agricultural techniques introduced during the green revolution. Ehrlich maintains that in light of growing global affluence, reducing total population as well as consumption is critical to maintaining environment protection and living standards and that current rates of growth are still too high for a sustainable future.
In 2011, as the world’s population passed the seven billion mark Paul Ehrlich (author of “The Population Bomb – 1968) argued that the next two billion people on Earth would cause more damage than the previous two billion due to the increased need to use more marginal land, damaging the environment and important resources.