There are many factors that affect the uneven distribution of the global population across Earth's surface. Physical factors like climate, topography, soil fertility, and water availability influence where people settle. Human factors such as political, economic, and technological developments also impact population patterns. Most of humanity lives in only 20% of the total land area, while vast sparsely populated areas account for 43% of land but only 2% of people. Population density calculations show large differences between overpopulated and underpopulated regions around the world. Developed countries have low birth rates and aging populations while developing nations experience high population growth that strains resources. Significant inequalities exist between developed and developing areas in terms of economic indicators, technology, education, healthcare access,

2.  Billion= mil millones / Billón= un millón de millones

3. The Earth, as you know, is inhabited by over 7.3 billion human beings.
However, they are not evenly distributed over the Earth´s surface.
 FACTORS THAT AFFECT POPULATION
DISTRIBUTION.
There are inequalities in population distribution because of different
factors: physical and human factors.
 PHYSICAL FACTORS
These are factors that occur in nature, making it possible for people to
obtain and use resources.
› Climate. A suitable temperature favours human settlement.
› Topography. People prefer to settle in low-lying areas near the coast
and in river valleys.
› Soil. The fertility of the soil, which favours the developed of agriculture,
has been an important factor.
› Water. In areas where water is scare, such as in deserts, the
population is usually low.

4.  HUMAN FACTORS
 These are consequences of human actions which
attract people to a territory or cause them to leave
it.
› Political. Decisions made by governments can influence
demographic behavior. For instance, policies encouraging
or penalizing births, regulating migration or causing
citizens to go into exile.
› Economic. People usually settle where there is
employment and services.
› Technological. Technological advances allow people to
alter natural physical factors. For example, agriculture can
be developed in previosly arid areas thanks to hydraulic
technologies.

5.  Most of humanity is grouped in only about 20 % of the
available land area, while there are also many
demographic vacuums or sparsely areas, which extend
over around 43 % of the land area, but are home to just
2 % of the population. NOTE: Look at the map of page 31 to see
the characteristics of population distribution.

6. › POPULATION DENSITY
 To analyse the number of people concentrated in an area, we
calculate the population density. This indicator allows us to make
comparisons between territories or countries of different sizes. To
calculate it, we use the following formula:
 For example: if we know that Africa has 30.310 Km2 of surface area
and 1.186.000 of total population, what is the population density of
this continent? Population density of Africa = 39, 13
inhabitants/km2
 You have to take into account that the population is distributed
unequally across the whole territory: there are areas that are
almost empty, whilst others are overpopulated.
 Therefore, if you see the map on page 32, we can identify the main
geographical areas where the population is concentrated.

7.  The population of the Earth is continuing to
grow. However, this growth is very uneven:
whereas in developed countries there are a low
natural growth, in developing countries natural
growth is higher (over 2 %).

8.  THE DISPROPORTION BETWEEN GROWTH AND RESOURCES.
In many poor countries, where the population is growing very fast, people go
hungry and development is restricted. This scarcity and lack of economic
prospects mean that these places are the starting point of migration. Besides,
the governments of these countries try to solve this situation by using
demographic policies that restrict the birth rate (for instance, in China until
2015)
 THE AGEING POPULATION.
In developed countries, such as Spain, we can talk about an elderly population.
It means not only that we have to pay pensions, healthcare and specialist care,
but also the productive capacity of society suffers, because if there are fewer
births, there are fewer workers. In many countries with this situation,
governments are putting pro-natalist policies into practice.
 INEQUALITIES IN DEVELOPMENT
Apart from inequalities in the demographics of countries, there are differences
between the developed countries (richest countries) and developing or
underdeveloped countries (poorest countries). To measure these differences,
the UN uses the Human Development Index (HDI) or INDICE DE
DESARROLLO HUMANO (IDH)

9.  GDP AND PERCAPITA INCOME
Gross domestic product (GDP). In Spanish language, PIB o Producto Interior Bruto. The value
(in money terms) of all of a country´s production of goods and services.
Per capita income (renta percápita). If the relationship between GPD and the number of
inhabitants is calculated, the per capita income is calculated.
In developed countries, these indicators are very high, whereas in developing countries are very
low.
 ECONOMY AND TECHNOLOGY
In developed countries: great level of technological development, tertiary sector the most
important economic sector and a large-scales trade.
In developing countries: agriculture is the primary activity and they do not have advanced
technology.
 EDUCATION AND HEALTHCARE
In developed countries: governments guarantees social benefits, such as public education,
health coverage and pensions. However, many inhabitants of developing countries do not have
access to these services. Sometimes, non-governmental organisations provide these services.
 SOCIAL INEQUALITIES
In developed countries, the distribution of wealth is relatively equitable. Most of the population
enjoys a level of purchasing power. On the other hand, there is very unequal distribution of
wealth in developing countries, with a rich minority and a large number of poor people.

10. The end