Population and the Environment: population, food, climate and soils

carrying capacity

the maximum number of species an environment can support indefinitely

population distribution

the pattern of where people live

china population distribution

over 90% live in the eastern part of the country as much of the west is covered by mountains and deserts

population density

the population of an area divided by the size of that area, number of people per square kilometre

population density of Libya

4 people per square km

population density of Bangladesh

1200 per square km

where are areas of high population density usually found

between 20 degrees N and 60 degrees N

population density can vary

within a country

global population reaches 1 billion

1804

until 1950, population growth was limited to

developed countries

population increase in england and wales from 1801 to 1901

9.4 million to 32.5 million

which populations grew most rapidly in the 19th century and why

north america and western europe because improvements in medicine and food production improved life expectancy and reduced infant mortality rates

population rates in developing countries in 19th century

remained stable as infant and maternal mortality high and famine common

population in 1950 vs 2017

2.5 billion in 1950 to 7.5 billion in 2017

population in 2025

8.2 billion

what has population growth post 1950 been driven by

developing countries

example of a country experiencing population decline

Japan where death rate is now higher than birth rates

changing population distributions

globally urban populations are increasing faster than rural ones so higher densities in cities

3 aspects of the physical environment that affect population

climate

soils

resource distribution

climate change and population distribution

in coastal areas where sea levels are rising people are moving inland and people living on small islands are having to abandon them

also causing nutrition levels to fall in some countries

climate type and global population distribution

few people live in arid areas like the sahara but many live in temperate and tropical areas which tend to have largest populations and highest densities as it is easier to produce food

soil fertility determines

the amount and type of food that can be produced in a region

how has soil fertility determined population size

it plays a role in where settlements have developed for example many cities like Naples are built near volcanoes as soil fertility is high

soil fertility and population change

soil erosion can cause people to move to other places as agriculture becomes more difficult

floodplains

very fertile so encourage large scale agriculture and thus large populations can be sustained

water and resources

population growth and distribution are linked to the availability of fresh water and natural resources for example most deserts have small populations because of lack of water

consequences of lack of safe water

food insecurity, health problems and death which causes population decrease

places with lots of naturally occurring food and fuel can

support large populations

energy and mineral resources cause

local concentrations of people

neolithic revolution

12,000 years ago

neolithic revolution and population

some people developed agriculture and began permanent settlements which grew in size as food supply became more reliable

industrial revolution

approximately 1760-1850

Britain’s population during industrial revolution

more than doubled

industrial revolution and population increase

death rates fell due to better food production and more money meant better diets

industrial revolution and changing population density

farming became less intensive as machinery developed so more people moved to cities to work which led to more concentrated populations

what happens to population as countries develop

rate of population growth first increases then decreases and populations become more concentrated in urban areas

global food production is

unevenly distributed

what has happened to food production globally in the last 50 years

it has increased as the area of land used for producing food has increased and huge technological advances happened in green revolution

what has technological development meant for food production

we can produce more food from less land

countries that produce a lot of food

East Asia and North America because they have temperate or tropical climates that are good for farming and a lot of investment in farming

countries that produce little food

central america and africa due to a lack of resources and funding for equipment, unsuitable climates and unsuitable land because of mountains or deserts

food consumption varies

between countries

what is happening to food consumption per person

it is increasing because as the world gets more economically developed people eat more

what countries consume the most food

developed areas like North America and Europe

why do developed countries consume the most food

they can afford to import a wide variety, have a culture of consumerism and more people have disposable income so can afford more food

China and food

beginning to consume more food as wealth increases and non traditional foods

variations of food consumption within countries

even within countries that have a high intake overall, some people may have limited access to food

types of food and development

meat costs more so it makes up larger proportion of diets in more developed countries

average amount of meat consumed per person per year in developed countries from 2013-15

65.7kg

average amount of meat consumed per person per year in developing countries from 2013-15

26.6kg

what type of system are farms

open systems where both energy and matter can be lost or gained to the environment

natural inputs into farmland

solar energy and rainwater

human inputs into farmland

seeds, fertilisers

stores in farm systems

soil, crops and animals

main output of a farm system

the food produced but also others like runoff

agricultural productivity

is a measure of the amount of food produced in an area so is the ratio of agricultural outputs (food) to inputs (capital and labour)

what is agricultural productivity affected by

the type of agricultural system

commercial farming

the production of crops or livestock to make a profit, usually has high productivity and is more common in developed countries

subsistence farming

when just enough food is grown to feed the family, common in Africa and Asia and has lower agricultural productivity

arable farming

plants

livestock farming

animals

intensive farming

as much is produced from the land as possible, there are 2 types of intensive farming

2 types of intensive farming

• capital intensive farming with a high input of capital and a low input of labour for an area of land

• labour intensive doesn’t involve much capital but uses a lot of labour

capital intensive farming

involves using fertilisers, pesticides and labour saving machinery

extensive farming

opposite to intensive farming, has a low capital and labour input for the area of land so produces less food than intensive farming

example of extensive farming

small numbers of livestock grazing large areas of land like livestock farms on the grasslands of north america

benefits of extensive farming

has less impact on the environment and provides better animal welfare

nomadic farming

farmers move from place to place to grow crops or graze animals on different land

example of nomadic farming

many livestock farmers in sub saharan africa roam over large areas to let their animals graze

agricultural productivity is affected by

the climate and soil

climate and farming

climate affects how successfully plants can grow in an area and how animals can survive there

climate and crops

some crops adapted to certain climactic conditions like pineapples being suited to tropical climates

climates that make growing crops difficult

tundra where the ground is frequently frozen

soil and farming

some areas unsuitable as there isn’t enough soil or it isn’t of high enough quality like deserts

different soils and types of farming

different soils suited to different types of farming so some aren’t fertile enough to grow crops and are used for grazing

5 climactic zones of the world

• arid

• continental

• polar

• temperate

• tropical

where are polar climates found

mainly above 66 degrees latitude in the northern and southern hemispheres

characteristics of polar climates

have the coldest temperatures on earth and little precipitation that mostly falls as snow

2 polar regions

Arctic in the North and Antarctic in the South

areas around the arctic that have a polar climate

northern canada, greenland and northern russia

arctic winter temperatures

often under -40 degrees

summer arctic temperatures

range between -10 and +10

precipitation in the artic

generally less than 100mm a year

antarctica

an ice covered continent at the south of the earth

antarctica winter temperatures

can be below -80 degrees

precipitation levels in Antarctica

interior very dry with less than 50mm a year but higher at the coast especially in the west

two main environments produced by polar climates

ice caps and tundra

ice caps

layers of ice permanently covering an area

tundra

has permanently frozen ground called permafrost which is land that stays frozen for more than 2 consecutive years

populations in the polar climactic zone

very low, 4 million in the Arctic and nobody lives permanently in Antarctica

agriculture and lifestyles in the arctic

agricultural productivity is low so traditional lifestyles based around subsistence

diets in the arctic and climate

arable farming generally not possible because of temperatures and frozen ground so arctic diets meat based

arctic meat diet

comes from hunting, trapping and fishing rather than farming livestock aside from deer

arctic people and migration

many of the species arctic people eat leave the most extreme environments in winter so some native peoples migrate seasonally so they are close to food

arctic people and adaptation to climate

favour clothing and building methods that provide insulation like the inuit people building stone houses into hillsides which are insulated by turf and snow

climate and development

temperature makes building places of business hard

infrastructure has to be designed specially

seasonal work

melting ice opens shipping routes

how is development of business hard in the arctic

low temperatures and frozen ground makes it hard to construct buildings and work

seasonal work in the arctic

tourism popular in the summer months especially on cruise ships and oil and gas reserves more accessible in the summer

melting of arctic ice in the summer

opens up shipping routes that makes trade between northern countries easier and commercial fishing can happen when there is less sea ice

temperature dictates the length of

the growing season