IB Environmental Systems and Societies

1. Topic 3.8
Environmental demands of
human populations

2. Environmental Demands of Human
Populations
• An ecological footprint is the hypothetical area of
land needed by an individual, group or society to
fulfil its resource needs and assimilate all waste
• An ecological footprint is not necessarily
sustainable. It may refer to an unstable
equilibrium (not that carrying capacity is real
rather than hypothetical, and refers to a steady
state equilibrium).

3. Ecological Footprint
• A country with a total ecological footprint
greater than its available land is in theory living
beyond its means

4. Factors affecting ecological footprint
• A large footprint could be caused by:
– Reliance on fossil fuels
– Increased use of technology (depending on its use)
– High levels of importation
– Large production of carbon waste
– High food consumption
– Meat-rich diets
• Footprint could be reduced by:
– Reduced resource consumption
– Recycling and reuse of resources
– Improved efficiency of resource use
– Reduced pollution
– Exportation of waste
– Use of technology (to increase carrying capacity and efficiency of land use)
– Reduced population

7. Approximate Ecological Footprints (2003)
• USA – 10.3 ha cap-1
• Australia – 9.0
• Canada – 7.8
• Germany – 5.3
• UK – 5.2
• Switzerland – 5.1
• Mexico 3.0 (2007 data)
• China – 1.6
• India – 0.8
In 2003, there were approx. only 1.8 ha available per person (including
productive marine areas). Therefore many of us are living beyond the Earth’s
ability to sustain the population
Which country do you think currently has the largest ecological footprint?

8. Calculations
• Ecological footprint is usually calculated in hectares
• 1 hectare = 10 000m2
• This is aproximately the size of a football field (0.6-0.8 ha)
or the field inside a 400m athletics track (about 1.2 ha)
• The 2 basic calcs usually carried out are
1. Per capita land (and water) required for food consumption
2. Per capita land (and water) required for carbon waste
absorbtion
• They are are added together to give the total footprint

9. Calculations
Per capita land requirement for food production (ha cap-1)
= per capita food consumption per year (kg cap-1 yr-1)
mean food production per hectare per year (kg ha-1 yr-1)
+ Food given as kg equivalents of grain
Per capita land requirement to assimilate carbon waste (ha cap-1)
= per capita CO2 emission per year (kg cap-1 yr-1)
total CO2 fixation by vegetation per year (kg ha-1 yr-1)

10. Problems with the Calculation
• It doesn’t consider the effects of pollutants
other than CO2
• It doesn’t consider land (or water) needed to
assimilate wastes other than CO2
• It doesn’t consider land lost through
urbanisation
http://myfootprint.org/en/your_carbon_footprint/

11. MEDCs vs LEDCs
more/less economically developed countries
1. Which has the higher ecological footprint?
2. Why does North America have a particularly high
per capita grain consumption?
3. Which are more dependent on fossil fuels?
4. Which has higher CO2 fixation and why?
5. Use the data to calculate per capita footprints:
Area Per capita grain
consumption kg
cap-1 yr-1
Grain
production
kg ha-1 yr-1
Per capita CO2
emissions
kg cap-1 yr-1
Net CO2 fixation
by vegetation
kg ha-1 yr-1
Africa 300 6000 200 6000
North America 600 300 1500 3000

12. The Human Population
• World Population Clock
• The current global birth rate is about 6 per sec
• The current global mortality rate is about 3 sec
• It took you about 10 seconds to read this, so how
much has the world population changed?
• How many children could a monogomous couple
have in their lifetime and not contribute to
population growth?

13. Policies on population dynamics and
growth
• There are 2 types of policy:
– Pro-natalist (eg. France)
– Anti-natalist (eg. China)
• Please make notes from the video clips for
each policy, and why it has been adopted

14. Fertility Rates
Fertility rate is the mean expected number of children born to a woman in her lifetime
(data from 2013 Census)

15. 2013 List by the CIA World Factbook

16. Methods of Population Control
• Population control may use one or more of the following practices although there
are other methods as well:
• Contraception
• Abstinence
• Reducing infant mortality so that parents do not increase their family size to
ensure at least some survive to adulthood
• Abortion
• Infanticide
• Improving status of women causing departure from traditional sexual division of
labour
• War
• Emigration
• Immigration reduction
• Sterilization
• Euthanasia

17. UN Millenium Development Goals
1. Eradicate extreme hunger and poverty
2. Achieve universal primary education
3. Promote gender equality and empower women
4. Reduce child mortality
5. Improve mental health
6. Combat disease (especially HIV/AIDS and malaria)
7. Ensure environmental stability
8. Develop a global partnership for development
http://www.mdgmonitor.org/

18. UN Millenium Development Goals
• Eight goals that respond to the major
development challenges that face the Earth
• They were adopted by 189 countries in 2000
• The goals are meant to be achieved by 2015
• They are an attempt by the UN to address
problems that individuals countries can’t or
won’t achieve in isolation
• They therefore represent INTERNATIONAL
rather than NATIONAL policy

19. Some Criticisisms of UN MDGs
• They lack specific objectives and the criteria
for success are largely subjective
• They don’t specifically mention agriculture
• Enrollment in education does not guarentee
learning
• Countries with biggest occurance of disease
often have least reliable data collection
• They seek local change largely through
external financing