Notes on Human Population and Environment (Environmental Studies)

Population Dynamics

  • Population: All individuals of a species living together in an area.
  • Demography: Statistical study of populations, allows for predictions about population changes.

Key Features of Populations

  • Size: Number of individuals in an area
  • Birth Rate (b): Number of births in a population.
  • Death Rate (d): Number of deaths in a population.
  • Rate of Natural Increase (r): $r = b - d$.
  • Population Density: $Population Density = \frac{# of individuals}{unit of space}$.

Types of Dispersion in Human Populations

  • Clumped Dispersion: Concentrated in specific areas (e.g., urban settlements).
  • Uniform Dispersion: Evenly spaced (e.g., housing developments).
  • Random Dispersion: Unpredictable distribution (e.g., settlers in unplanned areas).

Population Growth Patterns

  • Rapid Growth: Example: Kenya.
  • Slow Growth: Example: USA.
  • Zero Growth/Decrease: Example: Italy.
  • Factors Influencing Population Growth:
    • Agriculture advancements.
    • Technologies enabling expansion.
    • Improved sanitation and healthcare dropping death rates.

Population Growth Statistics

  • World population has significantly increased over the last 200 years.
  • Increased population in less-developed countries (98% growth).

Future Population Growth Factors

  • Immigration: Movement into populations.
  • Emigration: Movement out of populations.
  • Affect on growth includes natility (birth) and mortality (death).

Causes of Mortality

  • Developed Countries: Predominant causes include cardiovascular diseases (43%) and cancers (27%).
  • Least Developed Countries: High influence of communicable diseases (47%).

Challenges of Rapid Decline

  • Economic threats: Labor shortages, reduced government revenues.
  • Impact on public services: Higher pension/healthcare costs.

Carrying Capacity

  • Definition: Maximum population size supported by available resources.
  • Scientific advancements can increase carrying capacity, aiming for sustainable growth.

Urbanization Trends

  • Significant increase from 29% urban population in 1950 to projected 61% by 2030.
  • Migration to cities driven by economic opportunities and better living standards.

Environmental Impacts of Population Growth

  • Pollution: Increased greenhouse gas emissions.
  • Deforestation: Habitat destruction for housing.
  • Freshwater Issues: Pollution and waste from increased human activity.
  • Resource Depletion: Overuse of fossil fuels, affecting ecosystems.

Economic Development

  • Demographic transition as countries industrialize leads to slower population growth.
  • Challenges include poverty, war, and environmental degradation.