Populations and environment

• Population


  Amount of people in a defined area. The world population is approx. 8 billion.
• Distribution


  How a population is spread globally or regionally. The distribution of populations have changed - globally urban populations are increasing faster than rural ones, so populations are becoming less evenly distributed with higher densities in cities.
• Density


  Measurement of population per unit area.
• Global population change


  - The global population has risen rapidly since 1800.

  - Until 1950, most population growth was limited to developed countries:

  1) Until the 19th Century, the populations of North America and many countries in Western Europe grew rapidly. Improvements in medicine and food production increased life expectancy and reduced infant mortality rates.

  2) During the same period, the populations of developing countries remained stable - infant and maternal mortality rates were high, and famine was common.
• How climate affects population

  - It affects health and wellbeing of the population, dictating how many people can be supported in an area.

  - Affects agriculture as crops need certain conditions to grow, and food is needed to support a population.

  - The climate also affects incidence of disease, as some diseases thrive in certain climates which affects the population.

  - Climate change is affecting population distribution. For example, in coastal areas where sea levels are rising, people are moving inland, and. some people living on small islands are having to abandon they're islands.
• How soil affects the population

  - The soil fertility determines the amount and type of food that can be produced in a region.

  - It has played a role in determining where human settlements have developed and the size of populations.

  - Some countries such as Bangladesh, have large floodplains, which are very fertile. This supports large scale agriculture, which feeds the large population.
• How availability of natural resources affects population

  They are needed for a population to grow and be supported. A clean water supply is needed for hygiene, sanitation and drinking.

  - Many deserts have small populations because of the lack of water.

  - Places with lots of naturally occurring food and fuel eg. tropical rainforests are able to support fairly large populations.

  - Energy and mineral resources can cause local concentrations of people.
• How the 'green revolution' affected population

  This was the process of using technology and more efficient farming practices, in agriculture to maximise crop yields in the 50s and 60s. This created more food, especially in developing countries meaning a larger population could be sustained.

  An estimated 1 billion people are able to be fed as a result of the green revolution.
• How the 'Industrial revolution' affected population

  Beginning in the mid-1700s, the Industrial Revolution was the transition from majorly labour-intensive industry to technology manufacturing processes, including the use of machinery, fossil fuels, and factories. The process revolutionised agriculture, the manufacture of goods, transportation. medicine and other aspects of society, overall making life less labour intensive for many people. Industrialisation caused world population growth rates to increase. At the start of the Industrial Revolution, the population grew by 57%, and 100 years on the population grew by 100%.
• Global population density


  Urbanised areas are the most densely populated areas as many people move for job prospects and other opportunities. 55% of the population currently live in urban areas, and this is expected to rise to 2/3rds of the population by 2050.
• Why are some areas sparsely populated?

  eg. Sahara, Australia, Canada. Because they often have uninhabitable conditions, meaning the population can't be supported eg. lack of food to accommodate.
• Rate of population change

  There has been a shift from rapid population growth in richer countries, to rapid population growth in LIC's and a slowing in HIC's.
• Why do HIC's have the lowest population growth rates?

  This is due to a range of reasons, such as more contraception available, the emancipation of women, urbanisation, changes in society etc.
• Why do LIC's have the highest population growth rates?

  Mostly due to these countries 'catching up' and going through ​similar trends that high income countries went through in the 1900s. Overall though, global population growth rates are slowing.
• Food production


  Has tripled globally in the last 50 years, and global arable land has increased by 67 million hectares. More crops are being grown on more land and better quality crops.
• Why has food production increased globally?

  - Increased use of farming machinery which allows for more crops to be collected in a quicker time frame.

  - Increased use of other farming resources, such as pesticides to maximise yields.

  - Better farming management to maximise yields and create more farmable land.
• Distribution of food production

  ​Food production is unevenly distributed​.

  - More developed areas like Europe and North America, consume a lot. They can afford to import a large variety of foods, and many people have high disposable incomes so can afford more food.

  - Less developed areas, like Africa and parts of South America and Asia, consume less food per person as they cannot afford much.
• Food consumption


  Generally, has increased over time due to increased amount of people.
• Patterns of food consumption

  - LIC's consume less food than HIC's. This is because HIC's have more money to import food and invest in agriculture.

  - Africa consumes the least calories out of all continents. Over 27% of Africa is affected by severe food insecurity.

  - North America has the highest consumption rate. And Asia's consumption rate has seen the quickest growth.
• Socio- economic reasons - Cereals:

  50% of calories​ globally are from cereals, more so in developing countries (​54%​).

  ● In Africa ​and parts of ​Asia​, cereals account for up to ​70% of energy intake​, whereas in high income countries this number is around ​30%​.

  ● Rice ​consumption is highest in ​China ​and ​Eastern Asian countries​, although this is

  projected to ​decline​.

  ● Wheat​ consumption is highest in ​developing countries​ and increasing.

  ● Coarse grains​ are a major contributor to​ Sub-Saharan Africa​'s cereal intake.
• Meats:


  Developed countries eat the most meat, whereas ​developing countries tend to get protein from ​non-animal based sources

  ● Pig, sheep, cattle, and poultry ​are the main meats consumed in ​HIC regions like ​North America​ and ​Europe​.

  ● In the ​Middle-East​, ​India​, and ​Africa​, ​camels and goats ​are the dominant meat.

  ● Meat consumption is increasing​, especially in ​rapidly developing countries​. There's been a ​threefold ​increase in meat consumption in ​Asia ​since the ​60s​, and ​China

  specifically consumes ​nine times the amount of meat ​they once did.
• Sugars and oils


  ● Consumption of these products are ​highest in HICs ​due to the ​consumerist culture​.

  ● Consumption is ​rapidly increasing in developing countries​, but is still slower in the least

  developed countries.
• Inputs of agricultural systems


  - human labour and capital.
• Processes of agricultural systems

  1) Commercial farming - The production of crops or livestock to make a profit. It has high agricultural productivity and is more common in developed countries than developing countries.

  2) Subsistence farming - When just enough food is grown to feed the family. Its common in Africa and Asia, and has low agricultural productivity.
• Outputs of Agricultural systems:

  - Food crops

  - Other crops

  - Animal produce

  - Excess products to sell/trade
• Total factor productivity


  The best farmers will use inputs but get more output.
• TPF can improve by:

  - Improvement in crops - disease resistance, higher yields, drought tolerant.

  - Alerter harvest times.

  - Technology - Fertilisers, soils, watering, breeding.

  - Knowledge on animal diseases.
• Intensive farming:


  ​High inputs in relation to agricultural land to produce the highest possible output​. High inputs could include a lot of labour​, or ​high capital inputs​ - such as machinery - to maximise yields.
• Extensive farming:


  Low labour and capital ​inputs ​in relation to agricultural land, thus usually producing ​lower outputs​.
• Commercial farming:


  ​Agriculture with the intention of providing yields that can be sold commercially​, making a ​profit​. This type of farming is usually associated with intensive farming​, as more profits can be made using this management strategy.
• Subsistence farming:


  Self-sufficient farming​, where crops are grown only to support those growing the crops family or community, with little or no profit.
• How Human activities affected by the climate

  1) The world can be broadly classifies into 5 climatic zones - arid, continental, polar, temperate and tropical.

  2) Climate affects things like agricultural productivity and water availability - this means that population sizes and lifestyles in different climactic zones are different.
• Polar climates


  1) Polar climates are mainly found above 66degree latitude in the Northern and Southern Hemispheres, and experience the coldest temperatures on the planet.

  2) The have little precipitation, and the only precipitation that falls is as snow.

  
• The 2 polar regions

  1) The arctic at the north of the globe, it covers the Arctic Ocean much of which has a surface layer of ice.

  Areas around the Arctic Ocean such as north Canada, Greenland have a polar climate.

  In winter, temps are -40^ and in summer they range from -10 - 10.

  Precipitation is generally less than 100mm a year.

  2) Antarctica is at the South of the Earth:

  It is colder than the arctic - temperatures in the winter can fall below -80^

  The interior of Antarctica is very dry - it gets less than 50mm of precipitation each year. Precipitation is higher in coastal areas, especially in the west.

  *Polar climates produce two main types of environment - ice caps, which are layers of ice permanently covering an area, and tundra, which has permanently frozen ground called permafrost.

  
• Populations of the polar climates.

  - The populations are low in the polar climactic zone - the population of the Arctic is around 4 million, nobody permanently lives in Antarctica.
• Traditional lifestyles in the Arctic

  - Agricultural productivity is low, so traditional lifestyles are based on subsistence.

  - Arable farming isn't possible because few plants can survive such cold temperatures, and the ground is often frozen solid.

  - Therefore, arctic diets are usually meat - based - much of the meats come from hunting, trapping and fishing, but many Arctic people also raise reindeer for meat and milk.

  - Many of the species that Arctic people eat leave the most extreme environments in the winter - this causes some people to migrate seasonally, so they're closer to a food source all year round.

  - People have adapted to the cold temperatures with clothing and building methods that provide insulation.
• How climate affects development of polar regions

  - The low temperatures and frozen ground make it hard for people to work in polar environments or construct buildings there - this means that development is difficult. Buildings and roads have to be designed so they don't melt the permafrost.

  - There are several types of seasonal work. Tourism is popular during summer months , especially on cruise ships. Oil and gas reserves are more accessible in summer which also creates more jobs.

  - The melting of the arctic sea ice during the summer opens up shipping routes that make trade between northern countries easier. Commercial fishing can also take place where there is less sea ice.
• Arid climates


  - They are very dry and usually get less than 250mm of rainfall per year, places in this zone are classed as deserts.

  - Hot deserts are around 30^ North and South of the equator, eg. the Sahara in Northern Africa and the Namib in Southern Africa. Max. air temps are above 40 degrees.

  - Temperate deserts occur at higher altitudes eg. Central Asia. They are cooler than hot deserts but still Arid.

  - Rain is rare and unreliable - it falls in in infrequent heavy storms

  - Temp ranges can be huge - nights are usually much colder than days.

  
• Population of Arid climates

  - Population is low eg. The Sahara desert has around 2.5 million inhabitants. Distribution is uneven - there are clusters of settlement around water sources, and other areas are uninhabited.
• Challenges of an arid climate

  - Agriculture is impossible inmost areas because of the lack of rain, usually in the form of heavy conventional rainstorms. Rainstorms cause flash flooding and soil erosion.

  - Water can be drawn from oases to irrigate crops nearby. Crops such as cereals can be grown in the shade of taller food plants eg. date palms. These methods have allows some people to settle around oases.

  - Other native people are nomadic - they move from place to place. This allows people to keep grazing livestock despite the sparse vegetation - animals eat the plants in one place and then move on.