Population and the Environment Flashcards
what is the size of the population in an area influenced by?
how many people the environment of that area can support
what is population distribution?
the pattern of where people live
what is population density?
the population of an area divided by the size of that area
when did the worlds population reach 1 billion?
1804
what prevented the population from growing rapidly before 1800?
famine, disease and war
what has increased life expectancy and reduced infant mortality rates?
medicine and food production
what is the population predicted to reach by 2050?
9 billion
how has the distribution of populations changed?
globally, urban populations are increasing faster than rural ones
why are populations becoming less evenly distributed?
urban populations are increasing faster than rural ones
what are the three main aspects of the physical environment that affect populations?
- climate
- soils
- resource distribution
how does climate type affect the global distribution of population?
- few people live in arid areas, but many live in temperate areas
- tropical and temperate climates usually have the highest population densities because its easier to produce food
how is climate change affecting population distribution?
- in coastal areas where sea levels are rising, people are moving inland
- causing levels of nutrition to fall in some developing countries
how does soil fertility affect populations?
soil fertility determines the amount and type of food that can be produced in a region
how can soil erosion affect populations?
it can cause people to migrate to other places as agriculture becomes more difficult
how does climate affect populations?
- climate type affects the global distribution of people
- climate change affect population distribution
how does soil affect populations?
- soil fertility determines the amount and type of food that can be produced in a region
- played a role in where human settlements have developed and the size of populations
- soil erosion can cause people to migrate to other places as agriculture becomes more difficult
why has food production increased globally over the last 50 years?
- the area of land used to produce food has increased
- technological advances
why does East Asia and North America produce a lot of food?
- climates that are good for farming
- lots of investment in farming
why does Central America and Africa produce relatively small amounts of food?
- lack of resources and funding for farming equipment
- large areas of land that are unsuitable for farming as they are either mountainous, or they have poor quality or little soil
- unsuitable climates - some areas don’t get enough rainfall or are too hot
why is there a need for more food?
- the global population is increasing
- food consumption per person is increasing
how can resource distribution affect populations?
- population growth and distribution are linked to the availability of fresh water and other natural resources
- lack of safe water can lead to food insecurity, health problems, and death (can cause populations to decrease)
- places with naturally occurring food and fueler able to support fairly large productions
- energy and mineral resources can cause local concentrations of people
what is agricultural productivity?
a measure of the amount of food that is produced in a n area (its the ratio of agricultural output)
what is commercial farming?
the production of crops or livestock to make a profit
what is subsistence farming?
when just enough food is grown to feed the family
what is intensive farming?
as much as possible is produced from the land
what is extensive farming?
has low capital and labour input for the area of lands produces less food than intensive farming
what is nomadic farming?
farmers move from place to place to grow crops of graze animals on different land
are farms open or closed systems?
open
why is global good consumption unevenly distributed?
- the global population is increasing, so more food is being consumed
- food consumption per person is increasing the world becomes more economically developed
- food consumption varies between countries
- types of food consumed vary between countries at different levels of development
why can more developed countries consume a lot of food?
- they can afford to import a large variety of foods
- a culture of consumerism
- high disposable incomes, so can afford more food
why can less developed countries consume less food?
-they can’t afford as much food
why are emerging economies starting to consume more?
the wealth is increasing
in an open system what can be gained or lost from the environment?
energy and matter
what are some natural inputs to farmland?
solar energy and rainwater
what are some human inputs to farmland?
seeds and fertilisers
what is the main output of farms?
food
what re energy and matter transferred to and stored in?
soil, crops and/or animals
how is agricultural productivity affected by commercial farming?
it has high agricultural productivity and is more common in developed countries than developing countries
how is agricultural productivity affected by subsistence farming?
lower agricultural productivity
what is capital intensive farming?
farming has a high input of capital and a low input of labour for the area of land. involves using fertilisers, pesticides and labour saving machinery
what is labour intensive farming?
farming doesn’t involve much capital but uses a lot of labour
what are the two ways the physical environment is affected by agricultural productivity?
- climate
- soil
how does soil affect agricultural productivity?
- some areas are unsuitable for farming because there is not enough soil or the soil quality is poor
- different types of soil are suited to different types of farming
how does climate affect agricultural productivity?
- some climates make farming more difficult
- some crops are adapted to particular climatic conditions
- the climate affects how successfully plants can grow in an area and the animals that can survive there
what are the five climatic zones?
- arid
- continental
- polar
- temperate
- tropical
why are population sizes and lifestyles in different climatic zones often different?
climate affects things like agricultural productivity and water availability
polar climates are mainly found above what latitude in the northern and Southern Hemisphere?
66* latitude
how does the precipitation usually occur in polar regions?
as snow
what are the temperatures in the winter in polar regions?
often below -40*c
what are the temperatures in the summer in polar regions?
range from about -10c to +10c
what is the precipitation in mm per year in polar regions?
100mm per year
what is the precipitation in mm per year in the interior of Antartica?
less that 50mm per year
what are the temperatures in Antartica in the winter?
below -80*c
what are the two main types of polar climate environments?
- ice caps
- tundra
what are ice caps as polar climate environments?
layers of ice permanently covering an area
what is tundra in polar climates?
permanently frozen ground called permafrost
what is the population of the Arctic?
around 4 million
what affects traditional lifestyles in the Arctic?
- low temperatures
- low precipitation
why is arable farming not generally possible in the Arctic?
few plants can survive the temperatures and the ground is often frozen solid
agricultural productivity is low, so what are traditional lifestyle based onion the Arctic?
subsistence farming (produce enough food for yourself, but not enough to trade)
how does food cause some native people to migrate seasonally?
many of the species Artic people eat, leave the most extreme environments in winter, so they migrate to be closer to a food source all year round
how have Arctic people adapted to the cold temperatures?
with clothes and building methods that provide insulation
how does the climate affect development in polar regions?
- low temperatures and frozen ground make it hard for people to work and construct buildings, so development is difficult
- seasonal work - tourism summer and gas and oil reserves are all in summer, creating more jobs
- melting of Artic sea ice in summer opens up shipping routes, making trade easier, and commercial fishing is able to take place
how many mm of rainfall do arid areas get per year?
usually less than 250mm
where do hot deserts occur around the equator?
30* north and south of the equator
what is the maximum air temperatures of hot deserts?
above 40*c
how has climate change impacted agriculture?
- decreasing agricultural productivity in some areas
- increasing agricultural productivity in some areas
- changes in types of crops grown
- agricultural pests and diseases may increase in some areas
why is distribution uneven in arid areas?
there are clusters of settlements around water sources and other areas are left uninhabited