n. A time when the world's population reaches a maximum, after which it steadily declines due to reduced birth rates or global shortages of energy, food, and water.
2012
The world is on the threshold of what might be called "peak people." The world’s supply of working-age people will soon be shrinking, causing a shift from surplus to scarcity.
2011
We have peak cheap oil and global climate change combined with a shortage of phosphorus and water. We have reached the point where we will be unable to feed the population we have. Expect a decline not a growth. Some will starve, some will die in the inevitable resources wars and most of those wars will be over water not oil. I feel confident in predicting there will be less people on this planet in 20 years not more. We have reached peak people!
2004 (earliest)
Coal, nuclear, and renewable energy sources, combined with increasing efficiencies, may mitigate the effect of a plateau in oil and gas production. If not, the demographic effects of a no-growth or declining economy may be profound. Assuming some lag time, which could be relatively short, Colin Campbell comments that, "…the consequence of peak oil may be peak people."
This phrase is a play on the controversial term peak oil, coined in 1956 by the geologist M. King Hubbert. It refers to a time when the global rate of oil extraction reaches a maximum and thereafter declines steadily leading to either (depending on your political leanings and whether you wear socks under your Birkenstocks) a paradise of sustainability or a nightmare of barbarism (hence the controversy).