Human population growth and the demand for resources'

1
Human population growth and the demand for
resources.
2
Population and resource use.

• The UN Agenda 21 states that the unsustainable
  pattern of production and consumption ..is the
  major cause of the continued deterioration of the
  global environment.
• Industrialized populations (20) are using 85 of
  aluminum, chemicals 80 of paper, iron steel
  75 of timber, energy 60 of meat, fertilizers
  50 of fish, grain.
• Resource use is rising faster than world
  population - in 1995 at a rate of about 5.5 per
  year compared to the 1.6 population growth
  (WRI,1996)

3
Consumption fPAT

• Myers and others clearly show how resource
  sustainability is governed by IPAT or Impact
  population affluence technology.
• The greater the population growth, the greater
  the demand for goods and services per capita, and
  the greater the use of inefficient, wasteful or
  unsafe production technologies, the greater the
  impact on our natural resource base and overall
  environment.

4
Population outstrips innovation

• World population is growing at around 1.4 per
  year, doubling every 50 years. US population is
  growing at around 0.8.
• Current world population is 5.9b and the 2050
  best estimate is 9.4b (WRI, 1998).
• Population growth rates coupled with increasing
  aspirations for material wealth fuel the IPAT
  phenomena.
• The failure to transfer resource-efficient and
  clean technologies to the developing nations
  exacerbates IPAT.

5
US population and resources

• Since 1900, the US population grew 300 but raw
  material use grew 1700.
• Americans use per capita compared to world
  average
• 7 plastics, crude oil.
• 6synthetic chemicals and aluminum.
• 4 sand, gravel, copper.
• 3 nitrogen, iron steel.
• 1.5 cement. (PCSD, 1997)

6
US population - a case for ZPG?

• US population growth outstrips resource
  efficiency improvements.
• While it is true that per capita energy
  consumption in the US fell slightly from 1980 to
  1993, population grew by 32 m leading to an
  absolute increase in energy use of 10
  (PCSD,1997).
• A similar story exists for almost all classes of
  resources - per capita reductions have
  universally been wiped out by the effect of
  population increases.

7
How populations grow

• For every nation, the following formula governs
  population growth.
• ?Pm Pm-1/1000.(bmim)-(dmem)
• P population in millions at end of year
• ?P annual change in population
• b live births per thousand
• i immigration per thousand
• d deaths per thousand
• e emigration per thousand
• m year in question

8
Population projections

• The balance between births, deaths, immigration
  and emigration bi-d-e/10 gives the annual
  rate of increase r.
• This r can be used to project the growth of
  population over a particular time period.
• Pmn Pm.1(r/100)n
• P population in millions at end of year
• m a given year, e.g. 1996.
• n number of years into the future e.g 10
• r annual increase in population