This question is pretty vague and confusing.
Overconsumption – situation where resource use has outpaced the sustainable capacity of the ecosystem. ...
Overpopulation – too many people for the planet to sustain. ...
Acid rain.
Biodiversity loss.
Deforestation.
Desertification.
Global warming/climate change.
Habitat destruction.
source - wikipedia.org
The answer to this question would be: 14 days.
The skin is consist of keratinized cells that will keep multiplying. The cells start at the stratum basale and will keep moving up changing the old ones until it ends up at the outermost layer of stratum corneum.This process will take time around 2 - 4 weeks.