13.1 Human Population

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• Population growth impacts our environment and contributes to our ECOLOGICAL FOOTPRINT

• ECOLOGICAL FOOTPRINT: measure of water, land resources and pollution created to meet our demands

Ecological Footprint (ha. per capita)

A Brief History of Human Population Growth

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DENSITY DEPENDENT environmental FACTORS

• availability of food
• water
• shelter

4 WAYS HUMANS HAVE AVOIDED DENSITY DEPENDENT REGULATING FACTORS

1. Have expanded geographic range

• Less competition for space
• Could do this because overcame limiting factors in environment by:
• Making fires
• Building shelters
• Making clothes + tools
• Planning community hunts

• *** LANGUAGE
• Allowed communication of complex ideas
• Allowed vital survival skills to be passed down in subsequent generations

2. Increased carrying capacity

Shift from hunting and gathering to agriculture

3. Fossil Fuels

Industrialization

4. Public health advances

Reduced critical limiting factors
• Malnutrition
• Contagious diseases
• Poor hygiene
Reduced death rates + lengthened lifespan

Domestication of Plants and Animals

Advent of agriculture and livestock

CHanged Human Existence

• Livestock provided an ALTERNATE FOOD SOURCE for areas not good at producing crops
• Sheep, goats, pigs = first to be domesticated

Domestication of plants/animals transformed the population from small mobile groups of hunter gatherers into societies in PERMANENT VILLAGES and towns.

PEOPLE AND THE PATHOGENS: DISEASES ON THE RISE

Pathogens (disease causing agents) → Epidemics (disease that spreads rapidly through a population)

• BUT—highly dense populations also brought about RESISTANCE

INDUSTRIALIZATION put pressure on the environment because of increases in extraction/consumption of raw materials, pollution emissions + energy demands

THE INFLUENCE OF SCIENCE, TECHNOLOGY, AND MEDICICNE

THE INDUSTRIAL REVOLUTION lead to major changes in:
• Agriculture
• Manufacturing
• Mining
• Transportation
• Technology

Advances in chemistry

• Production of new compounds e.g. SYNTHETIC FERTILIZERS
• Allowed more food production

Public Health Advancements
• Sanitation improvements
• Waste removal
• Improving water quality
• Researching causes/understanding transmission/access of infectious diseases
•DEVELOPING ANTIBIOTICS AND VACCINES

Negative Results of an Increasing Population

• Land erosion from deforestation for housing
• Loss of large areas of habitat for agricultural purposes
• Drainage of wetlands
• Depletion of forests for logging
• EXTINCTION/DECLINE OF SPECIES
E.g. passenger pigeons

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