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Relationship between population size and resource consumption
Transcript of Relationship between population size and resource consumption
size and resource consumption
What do we already know?
"The theoretical measurement of the amount of land and water a population requires to produce the resources it consumes and to absorb its waste under prevailing technology"
Population growth will lead to increased food demand
-> Less food per capita
Increased mortality - positive checks
Decreased fertility - negative checks
Reduction of population
Resources optimist - work was based on studies of shifting cultivation
Population growth would result in an increased demand for food
Improved agricultural productivity or better transportation (e.g. "Green revolution", technology, human ingenuity)
Population continues to grow
Malthus and the neo-Malthusians
The Population Bomb (1968)
“Each year food production in the undeveloped countries falls a bit further behind burgeoning population growth, and people go to bed a little bit hungrier”
"The battle to feed all of humanity is over," the Ehrlichs warned. "In the 1970s and 1980s, hundreds of millions of people will starve to death in spite of any crash programmes embarked upon now. At this late date, nothing can prevent a substantial increase in the world death rate..."
in 2008, he publishe, "The Dominant Animal: Human Evolution and the Environment" with his wife.
"The charm and the curse of the population debate is that one must inevitably return to the subject of fruit flies. When a female finds a pile of rotting bananas, she lays her eggs and the population explodes. When the bananas are used up, the population crashes. Some females find another pile of fruit, and the process starts over. "Our problem is we only have one pile of bananas," Ehrlich says." (http://www.guardian.co.uk/environment/2008/jul/16/humanconsumption)
The Club of Rome
small international group of professionals met at a quiet villa in Rome.
Invited by Italian industrialist Aurelio Peccei and Scottish scientist Alexander King
1972 - Published, "The Limits of Growth" report - 12 million copies were sold in 30 languages
The dilemma of prevailing short-term thinking in international affairs
Concerns regarding unlimited resource consumption in an increasingly interdependent world
Highlighted fragile relationship between economic development and environment
We have a choice:
Population growth + increased demand for food
-> Either resources will be exhausted and mortality will increase
Or we regulate population growth and reduce fertility and increase industrialisation
1996 “The Ultimate Resource”
Scarce -> expensive
Abundant -> cheap
BUT, with time the price of almost all natural resources has decreased
Does this mean resources are becoming less scarce/more abundant?
Short run: population growth will drive up demand for resources (prices will rise)
High prices encourage entrepreneurs to find new resources
Billiard balls: ivory->celluloid/plastic
Net result: resources are cheaper and more plentiful than before population growth
Canada could support 50 million people
It easily has the capacity to support its population and export food
A country can have a low population density and still be overpopulated (e.g. north-eastern Brazil)
A country can have a high population density and still have the capacity to provide for itself (e.g. through technological innovation - Netherlands)
If knowledge of new technology is not available - there will be no population growth
How has food production increased?
OVERALL AMOUNT OF LAND USED FOR FOOD PRODUCTION HAS INCREASED (per capita the land used has decreased)
reclaiming land from the sea
cross-breeding of cattle
high-yield varieties of crops (HYVs)
terracing on steep slopes
growing crops in greenhouses
using more sophisticated irrigation
new foods, e.g. soy
use of artificial fertilizers and pesticides
farming native species of crops and animals
Who was right? Who is right?
Since Malthus, food production has increased dramatically.
On a global scale, absolute food production since 1961 has increased.
Per capita food production has also increased globally.
Some neo-Malthusians believe we have passed the point where we can all live in comfort. Evidence:
High IMRs in some sub-Saharan African countries
People continue to die from preventable diseases
People continue to lack access to safe drinking water and sanitation
Russia - declining population (rural-urban migration, low life expectancy, loss of subsidies)
Madagascar - 30% of land that was considered arable is now irreversibly barren
UN Population Projections
Projections suggest that the world population will peak during the 21st century - but is this because Malthus was right? Or because fertility rates are decreasing naturally?
2004 study by Paul Ehrlich & Kenneth Arrow
central concern has shifted from population growth to consumption ratio
What do you think?