1.1: Exploring human populations Flashcards
(39 cards)
By the end of 2020 its estimated that the human population would reach:
7.8 billion
How many people are added every minute?
140
Natural ecosystems are under threat because of..
over-consumption of resources and creation of pollution
What did the Global Footprint Network reported?
That the human population on earth had already consumes its yearly production
Why does the impact of human population on the earth depends on how resources are used and distributed?
Because of the huge differences in resource use among people
What does overpopulation depend on?
Density of population
ratio of population to available sustainable resources
how resources are managed and distributed
List the 7 types of resources
- Fresh water
- Food
- Wood
- Non-renewable energy
- Renewable energy
- Metals and Minerals
- Land
What is the human carrying capacity?
Carrying capacity means the population size for a given species that a specific environment can sustain indefinitely, given the food, habitat, water, and other necessary resources available.
According to Malthus, human population size is regulated by its food supply when
the number of people exceeds the available food supply.
The regulations on human population growth are either
- voluntary (for example, birth control, abstinence, or delayed marriage)
- involuntary (for example, famine, disease, or war).
Define an ecological footprint
is a measure of a person’s daily demands on the earth’s ecosystems. It is the amount of biologically productive area of the earth (land and sea) needed to produce the resources a person consumes, in addition to the area needed to absorb and treat the resulting waste. It is measured in global hectares (gha).
What does a global hectare represent?
A global hectare represents the biological productivity found on one “average” hectare (a measure of area) of the biologically productive parts of the earth.
it is estimated that each person on earth needs ______ to meet their needs, but this is not distributed evenly.
2.1 gha
The ecological footprint of the average Canadian is about
7.6 ha
In developed countries:
birth rates have recently declined.
birth rates in some countries are so low that their populations would begin to shrink if they didn’t use immigration to keep their populations stable.
Describe the demographic transition
stability - high - stability - decline
Why did the global population in stage 1 stayed for thousands of years?
- Agriculture and rise of complex societies increased birth rates
- Disease and wars kept mortality rates high
When did the Industrial Revolution began? Where?
mid-1700s and began Europe and North America
What happened when the Industrial Revolution began?
- New machines and factories (more goods and cheaper)
- People migrated from farms to cities
- Higher standard of living (less mortality rates and more birth rates)
- Modern farm machinery and fertilization meant more food could be harvested from same amount of land
What happened because of high mortality rates?
People had more children as an insurance policy
People had more children to help in farming
Young women started having families at an early age
As the Industrial Revolution progressed, the new lower mortality rates combined with traditionally high birth rates created a
period of exponential growth.
When Industrial Revolution did not spread as fast to developing countries?
- Most were still dependent on small-scale agriculture until the early 1900s.
- Gradual improvements in medical care and agricultural practices helped to reduce their mortality rates. This led to small increases in their population.
- However, infant mortality rates remained relatively high, so population growth was moderate.
Risk of famine was also high.
Who created the Green Revolution?
an American plant breeder named Norman Borlaug
What happened during the Green Revolution?
- New varieties of wheat and rice
- Synthetic fertilizers, mechanized irrigation, and petroleum-based herbicides and pesticides food supply
