The urgent need to stabilise population

numbers

Jenny GoldieSustainable Population Australia

incpresident@population.org.au

Global population

• 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

• Ecosystem health• Food production• Climate change• Peak Oil

Ecosystem healthMillennium 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 HealthMillennium 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 20000.07h 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:

• 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

• 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