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Transcript
The urgent need to stabilise
population numbers
Jenny Goldie
Sustainable Population Australia inc
[email protected]
Global population
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Global population 6.48 billion
Still grows by over 70 million a year
9 billion by 2050 – up to 12 billion
Most future growth in developing world
Growth variable – TFR 1.2 – 8
Many low pop growth countries wealthy
Most high pop growth countries poor
Barriers to further growth
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Ecosystem health
Food production
Climate change
Peak Oil
Ecosystem health
Millennium Ecosystem Assessment:
• Humans have changed ecosystems more
rapidly and extensively in the last 50 years
than in any other period
• Ecosystem changes that have contributed
substantial net gains in human well-being and
economic development have been achieved
at growing costs in the form of degradation of
other services.
Ecosystem Health
Millennium Ecosystem Assessment:
• The degradation of ecosystem services could
grow significantly worse during the first half
of this century and is a barrier to achieving
the UN Millennium Development Goals.
• The challenge of reversing the degradation of
ecosystems while meeting increasing
demands can be met but require significant
policy and institutional changes.
Food production
• 800 million undernourished (hungry) with no
money to buy available food
• 3 billion malnourished
• Many countries not self-sufficient in food
• Total calorie production has kept pace with
population growth thanks to oil crops, but…
• per capita grain production has fallen for past
two decades (380 to 330 kgs/person)
Food production
• Yields still increasing but rate declining
• Land gained from deforestation about equal
to land lost to houses, roads & degradation
• 10 m hectares annually lost to soil erosion
• 10m hectares annually lost to salinisation
• Quarter of all arable land - declining
productivity
Food production
• Little good land left to farm (maybe Brazil)
• Cannot expect dramatic gains in yield
• Diminishing returns (extra fertiliser doesn’t
increase yields after a point)
• Falling water-tables from over-pumping
• Loss of farmland to ethanol
• Loss of cropland and rangeland to erosion
(desertification)
Food production
• Average grainland world wide:
0.23h in 1950
0.11h in 2000
0.07h in 2050 (at 9b and no loss of land)
• Decline in resources will lead to drop in living
standards and ultimately conflict
• “World food security could begin to eclipse
terrorism as the over-riding concern of
governments.” - Brown
China
• Falling water tables, drying rivers and
polluted water
• Annual grain harvests dropping since 1998
• 1.4 b people - still growing 0.6% a year
• Grain deficit (demand minus supply) 37.5 m
tonnes this year
• Imported $US14.3b farm produce half 2004
• Will soon import 30-50 m tonnes annually
Climate change
UNFPA (2001)
• increased severity and intensity of storms
• flooding and soil erosion
• accelerate the extinction of plants and
animals
• shift agricultural zones
• threat to public health through increased
water stress and tropical disease
Climate change
IPPC:
• 0.7 degrees C. increase last century
• 1.4 – 5.8 degrees C. this century
• Both adverse and beneficial impacts
• Richer countries (temperate) enjoy
some beneficial effects
• Poorer countries (tropical) endure
adverse effects
Climate change
Unknowns:
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Effects of increased CO2 in the field
Potential losses from pests and disease
Spatial variability in crop losses
Effects of extreme climate events on
crops and livestock
Climate change
• Global warming has already cut rice harvests
by 10% for every 1 degree inc in night-time
temperatures
• Rice production needs to increase 1%
annually to keep pace with demand….but
• 3.5 degree rise this century would see rice
yields decline another 30%
• Modern strains of rice may be resistant to
rising temperatures (IRRI – Philippines)
Climate change
Rising seas
• Half metre rise by 2100 will double number of
people affected by flooding (to 100 m)
• Coastal land and mangroves damaged
• Severe implications for fish-stocks from a
warming ocean (wind strength and ocean
circulation will affect breeding and migration
patterns)
Peak Oil
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Global supplies will peak soon (Simmons)
Oil effectively gone in 40 years
Current production 85 mbd - 75 mbd in 2015
Faster oil extracted, faster pressure dissipated
Overproduction leads to production collapse
New fields often poor quality (Kazakhstan)
Tar sands extraction very energy-intensive
Peak Oil
Implications
• Higher energy prices
• Higher prices of transported goods eg food
• Air travel and tourism adversely affected
• Recession likely with inflation and high
unemployment and consumer debt
• Plastics, medicines, packaging, synthetic
fabrics, road surfaces, cosmetics, detergents,
fertilisers will become scarcer
Peak Oil
Implications for agriculture:
• 70% water used for irrigation
• More expensive to pump water around
• Uneconomic to pump from deep aquifers
• Land converted back to dryland farms,
meaning less food available
• More expensive to drive modern machinery
• Fertilisers and pesticides increasingly
expensive, meaning lower yields
Population
• Increased demand for food and water as
population grows
• Yet less food and water available because of
higher energy costs
• Already 1.1b without adequate water and
2.4m without adequate sanitation
• Need to stabilise atmosphere with 60%
reduction in GGE
• Urgent need to reduce per capita demand in
rich countries but lift poor out of poverty
Population
• Need to lift yields to feed more people at very
time it will be difficult to do so
• Ecosystems already stressed so cannot take
on new land to farm
• May need to revert farms to forest to retain
ecosystem services
• Technology can help but will not allow
business-as-usual
• Only solution: rapid stabilisation then
reduction of population