INTRODUCTION
Population
growth, though a source of development is commonly regarded as one of the most
dreadful cause of environmental degradation. Population can be defined in terms
of a particular section, group, or type of people or animals living in an area
or country. Population growth has been defined in diverse ways by various
authors and institutions (Wikipedia1).
In this context, population growth refers to the growth of human population in
the world in terms of how the number of individuals in a population increases
over time.
According to The United
International Strategy of disaster reduction, environmental degradation is the
reduction of the capacity of the environment to meet social and ecological
objectives and needs. (UNISDR, 2009)
A report by the United
Nations population Division 1998, records that the world population has doubled
since 1950. About 90 million babies are born each year. At this rate, by the
year 2050, global population will reach 10 billion. The current world
population is on average very young and has many years of reproductive life
ahead. Because of this the population will grow even if the fertility rates
seem to decrease. The population growth takes mostly place in developing countries.
These countries are in charge of 90 percent of current population growth. It
has been estimated that by the year 2025 even 84 percent of the world’s people
will live in developing regions.
Most estimates for the
carrying capacity of the earth is between 4 billion and 16 billion. Depending
on which estimate is used human population may or may not have already
occurred. The main concern therefore is the rising population and its
auspicated effects on the environment especially in the developing Nations where
we have a high population growth rates and poor modes of food production.
The environment and key
natural resources in most African countries have been increasingly threatened
by escalating and unsustainable pressures from fast-growing populations (UNEP, 1999). Nations with high
population growth are often not able to produce enough goods to meet their
basic needs of their inhabitants.
An expansion of the
production of various goods seems necessary in order to sustain the population.
However an increase the amount of goods produced may aggregate environmental
problems; in particular if the less developed countries follow the pattern of
Development of Western Industrialized countries.
The demand placed on
the environment to provide resources for increased human activities such as
industrialization, exploitation of water and land resources and Urbanization,
and absorption of wastes steadily increases and long term effects is the
simultaneous degradation of the environment.
The aim of this paper
is to examine how increased world population through human beings change of
life degrades the environment. Man degrades the environment through his direct
or indirect acts that include:-
Ø Altering
and disturbing the natural resources
Ø Through intensive Agriculture practices
Ø Development
of cities (Urbanization)
Ø Rapid
growth and expanding off industries
URBANIZATION
Urbanization
refers to the general increase in population and the amount of
industrialization of a settlement. It includes increase in the number and extents
of cities. It symbolizes the movement of people from rural areas to urban
areas.
Urbanization
happens because of the increase in the extent and density of urban areas. The
density of population in urban areas increase because of the migration of
people from less industrialized regions to more industrialized areas
Causes of urbanization
Urbanization
usually occurs when people move from villages to cities to settle, in hope of a
higher standard of living. This normally takes place in developing countries
In
rural areas, people become victims of unpredictable weather condition such as
drought and floods, which can adversely affect their livelihood. Consequently
these people move to cities in search of better life. This can be seen in areas
like Budalangi, Kano plains, Tana Delta where these people move to Kisumu,
Nairobi, and Mombasa etc to escape poverty.
Cities
in contrast, offer opportunities of high living and are known to be places
where wealth and money are centralized
Most
industries and educational institutions are located in cities whereas there are
limited opportunities within rural areas. Thus further contribute to migration
to cities
Environmental impacts of
urbanization
Temperature
Due
to factors such as paving over formerly vegetated land, increasing number of
residences, and high-rise apartments and industries temperatures increases
drastically.
Air pollution
Factories
and automobiles are symbols of urbanization. Due to harmful emission of gases
and smoke from factories and vehicles, air pollution occurs.
Most
of the ambient air –pollution in urban areas comes from the fossils fuel
industry, motor vehicles, heating and electricity generation. In some cities
the main air polluter is the domestic heating which results into indoor air
pollution. Indoor air pollution may pose an even greater hazard for human
health. Cooking and heating with wood, crop residues, animal dung and low
quality coal produces smoke that contain dangerous particles and gases which
may include various toxic and carcinogenic chemicals, heavy metals, trace
organic chemicals and fibres, photochemical pollutants, lead,carbon monoxide,
which are much more harmful to human health (HABITAT 1996). When fuels such as
these are burned indoors, using inefficient stoves and poor ventilation, they
can cause tuberculosis, other respiratory diseases and blindness (Mishra,
Rether ford and Smith,1999). In fact, indoor air pollution from cooking and
heating with unsafe fuels has been designated by the World Bank as one of the
four main environmental problems in developing countries.
Traffic:
almost all cities have changed to motorized road vehicles, which has increased
the use of fossil fuels and increase in green house- gas emissions. The
explosive growth in the number of road vehicles is a big problem in many
cities. Many city centers have major difficulties trying to cope with the
chaotic automobile traffic. The traffic jam is extremely bad in many cities and
transport traffic in the city area at least during rush hours is very slow. The
pollution is high due to constant traffic and cause respiratory diseases to
city habitants (HABITAT 1996)
Water and drainage
systems
When
urbanization takes place, water cycles changes and cities have more
precipitation than surrounding areas. Due to damping of sewage from factories
in water bodies, water pollution occur which can lead to outbreak of epidemics.
The
lack of sanitation and sewage treatment is the biggest factor regarding water
pollution. Local water bodies are used as dumping ground for untreated water
from urban areas and industries. For example in Bangkok 90 percent of
industrial wastes including hazardous chemicals are discharged without
treatment (UNEP 1999).
Many
rivers in developing countries are more like open sewers than rivers. Most of
the centers in these regions do not have drains or even services to collect the
garbage. The cities that are close to the coast often dump untreated sewage to
the sea. Most of the coastal cities have serious problems with dirty,
contaminated beaches and water which is a serious health risk to the bathers
and for the whole city (HABITAT 1996)
Habitat destruction and
loss of biodiversity
To
make an area urbanized, a lot of forested areas are destroyed. Usually these
areas would have been habitats to many birds and animals
Population
growth leads to expanding human settlements and increasing demand for food,
fuel and building materials. Modernization of agriculture also threatens
potentially valuable local crops.
Such
development programmes such as creating reservoirs, mining, forest clearing,
lying of communication and transport networks etc. I t is estimated that in the
worldwide perspective slightly over1000 animal species and sub-species are
threatened with extinction rate of one per year, while 20000 flowering plants
are thought to be at risk (Compendium of Environment Statistics 2000)
POPULATION
GROWTH AND SETTLEMENT
Rapid population growth
has outstripped the ability to deliver adequate services such as education,
health care, safe water, sanitation, and waste removal. The increased
population exerts pressure on existing facilities and even the ecosystem since
it’s beyond the carrying capacity of these facilities hence calling for
expansion or creation of new facilities to cater for increased population. Growing
population is one of the main forces driving a country’s overwhelming
environmental challenges.
One of the major
problems brought about by increase in population is settlement. Population growth affects migration and
settlement patterns and their relationships to the physical environment. As population increases, settlements sprawl,
and take over forested and agricultural land, fragmenting and degrading
remaining natural areas. The clearing of forested to pave way for settlement
impacts the environment negatively causing degradation. The cleared environment
paves way for soil erosion as there are no trees to hold the soil together;
this in turn causes pollution of the air when windy and pollution of water
bodies during rainy season hence affecting aquatic life and human health.
Clearing of the trees also causes loss of biodiversity. Some plant and species
are lost hence affecting the ecosystem balance.
Trees act as
windbreakers and clearing the forest will mean no windbreakers. It will also
lead to destruction of water catchment areas. The medicinal value of the tress
will be lost by destruction and there will be increased of carbon dioxide in
the atmosphere as there will be no carbon sink, this will lead to global
warming causing forest fires, skin cancers and rise in sea levels causing
flooding resulting to displacement of people and coastal erosion.
Taking up of
agricultural land to put up settlements will reduce arable land hence reduce
food production and therefore leading to food insecurity.
Increase in population
makes it difficult for a nation to plan; it leads to increased poverty levels,
low life expectancy and high infant mortality. The pressure from increasing
population is a major hindrance to sustainable development hence a country
remains under developed.
Ongoing rural to urban
migration, high natural birth rates, and poor or Inappropriate country’s
planning conspires to continue degrading the environment and this has impacts
on human health and the economy. For the country to achieve the MDGs progress
must be made, an important target is stabilizing the fertility rate as
recommended by the Population Policy for Sustainable
Development (CBS
2004). The country can achieve more
sustainable land use if it combines planning and development with environmental
management.
INCREASED
POPULATION AND ITS IMPACT THROUGH AGRICULTURE TO ENVIRONMENT DEGRADATION
Agricultural impact is
such direct on the environment because it involves man manipulating the
environment to gather for his needs/food. Since time in memorial man has been
dealing with farming. With the increased population man has been force to clear
more land to gather for the increased needs of his family.
The era of Agricultural
revolution cleared fast lands to pave way for the green revolution.
Agricultural revolution cleared 10% of the earth’s land surface of either grass
or trees so that it could be ploughed planted to crops.
Agriculture has changed dramatically, especially since the
end of World War II. The world population has shot from 370million after the
Great Famine and the Black Death in Britain in 1350 to 7 Billion in 2012 March.
The sharp increase in worlds population demands that more land should be
brought under Agricultural use or use intensified farming methods to increase
food production this in turn causes harm to the environment either directly or
indirectly.
Today the 7 Billion people cultivate over 40% of the worlds
land and .Total farmland has been increasing drastically since 1992 to 2002 the
Agricultural land increased by 5 Million
Hectares
Of the total 13 Billion hectares of
land area on Earth, Cropland accounts for 11% ,pastureland 27%, Forerstland
32%, urban land 9%the rest 21% unsuitable for crop farming.(World watch
Institute http://t.co/uOQdMqrp )
Increased population through Agriculture impacts on
Environmental degradation in the following ways;
i.
Burning
of forests to create new lands for Agriculture
ii.
Use
of pesticides and herbicides.
iii.
Soil degradation and pollution
iv.
Increased
pressure on Arable land
Burning of forests to create new
lands for Agriculture
Man is constantly colonizing new lands to get food for the
increasing population. Burning includes human-initiated burning of vegetation
for land clearing and land-use change as well as natural, lightning-induced
fires. Scientists estimate that humans are responsible for about 90% of biomass
burning with only a small percentage of natural fires contributing to the total
amount of vegetation burned. Man is forced to clear new lands by burning the
vegetation down to get more land burning vegetation releases large amounts of
particulates (solid carbon combustion particles) and gases, including
greenhouse gases that help warm the Earth. Greenhouse gases may lead to an
increased warming of the Earth or human-initiated global climate change. In the
long run the cleared forests which used to Act a carbon sinks are no more and
this leads to increased levels of carbon in the atmosphere.
Use of pesticides and Herbicides for
Agriculture
The increased population is always forced to use pesticides
herbicides and fungicides to reduce the number of competitors in the tropical
level so that food production is maximized.during their
application they also affect non-target
plants and animals. Repeated application leads to loss of biodiversity. Many pesticides
are not easily degradable, they persist
in soil, leach to groundwater
and surface water and contaminate wide environment. Depending on their
chemical properties they can enter the organism, bioaccumulation in food chains and consequently influence also
human health.
The French incident in
two French Caribbean islands, Martinique and Guadeloupe, which were heavily
contaminated by pesticide chlordecone after several decades of its spraying on
bananas plantations. Initially, the use led to higher crop yields but each
season more chlordecone was required to achieve the same results. As a
consequence, this tropical paradise with about 800,000 inhabitants now faces an
environmental disaster with far-reaching ecological, economical and social
impacts.
Water contamination is one of the most affected component of the ecosystem when it comes to use of Pesticides.
Pesticides can get into water via drift during pesticide spraying, by runoff from treated area, leaching through the soil. In some cases pesticides can be applied directly onto water surface e.g. for control of mosquitoes. Water contamination depends mainly on nature of pesticides (water solubility, hydrophobicity), soil properties, weather conditions, landscape and also on the distance from an application site to a water source. Rapid transport to groundwater may be caused by heavy rainfall shortly after application of the pesticide to wet soils. (pesticide action Network Europe 2008)
Soil micro-organisms play a key role in soil. They are essential for
maintenance of soil structure, transformation and mineralization of organic
matter, making nutrients available for plants when we are using pesticides we
harm and kill this micro-organism by either deforming them or completely
whipping them out of the ecosystem
Soil degradation and
Pollution
All the actions that man venture into revolve around the crust. Man got
direct impact on the soil and he causes stress to it by application of
fertilizers, fungicides, overgrazing and contact cultivation. All this
activities man venture into so that he can get food for the increased
population not knowing that he/she is harming the environment greatly
Pesticides
enter the soil via spray drift during foliage treatment, wash-off from treated
foliage, release from granulates or from treated seeds in soil. Some pesticides
such as soil fumigants and nematocides are applied directly into soil to
control pests and plant diseases presented in soil. Fertilizers are also
applied direct to the soil.
Increased pressure on Arable land
The geometric rise in
human population levels during the twentieth century is the fundamental cause
of the loss of biodiversity. It exacerbates every other factor having an impact
on both Terrestrial (Grassland, mountain, Forest and Desert ecosystems) and
Aquatic ecosystems, It has led to an unceasing search for more arable land for
food production, livestock grazing, for wood for fuel, construction, and
energy.
Balmford, et al.,
(2001) have demonstrated that human population size in a given tropical area
correlates with the number of endangered species, and that this pattern holds
for every taxonomic group. Most of the other effects mentioned below are either
consequent to the human population expansion or related to it.
EFFECTS
OF OVERPOPULATION ON NATURAL RESOURCES
o
Inadequate fresh water for drinking as
well as sewage treatment and effluent discharge.
o
Depletion of natural resources
especially fossil fuels.
o
Increased levels of air pollution ,
water pollution, Soil pollution, noise
pollution,
o
Deforestation and loss of ecosystem that
sustain global atmospheric oxygen and carbon dioxide balance. About 8 million hectares of forest
are lost every year.
o
Changes in atmospheric composition and
consequent global warming.
o
Irreversible loss of arable land and
increase in desertification.
Mass
species extinction from reduced habitats in tropical forests due to slash –and-
burn techniques that are practiced by shifting cultivators; especially in
countries with rapidly expanding rural population present extinction rates may
be as high as 140,000 species lost per year. As of February 2011 IUCN Red List,
a total of 801 animal species having gone in recorded history.
Stealing
of natural resources to survive conflict over scarce resource. The resources to
be considered when evaluating whether an ecological niche is over populated
include clean water, clean air food shelter and warmth.
The
demands placed on the environment to
provide resources for human activities and to absorb wastes have grown steadily
with rising population and increasing per capita consumption. Currently the
highest fertility rates are found in countries suffering from poverty ,food
insecurity and natural resource degradation.
Given
that many natural resources such as many
natural resources( such as water, soil, forests
and fish stocks) are already being exploited to or beyond their limits
in at least some regions. The efforts required to meet the needs of additional
300million people will be immense.
Globalization
of population movements is needed like movement of capital and free trade in
goods and services through WTO, for people to live and work wherever they like.
This is the one change that allow optimization of the population to environmental carrying capacity and a rapid reduction in economic and solid
disparities between countries.
HOW
POPULATION GROWTH DEGRADES ENVIRONMENT TROUGH INDUSTRIALIZATION
Industrialization was a
key component that man discovered in the mid 18th Century. The
advent of Industrial revolution tremendously reformed most sectors in the world
and it made work efficient, created employment and also made life comfortable.
The second phase of industrialization begun in the 1860-1914. The
second phase of industrialization was characterized by a rapid expansion of
industries that developed because of new sources of energy hydroelectricity and oil.
The change in industrialization system was prompted by the increased
demands of the public due to the growing population. The world population had
been increasing steadily from the onset of Industrial revolution and there was
need to seek for improved of production and acquiring of goods and services. During
the onset of industrial revolution there was an increase in population due to
increased food and diet.
During the Agricultural
and Industrial Revolutions,
the life expectancy
of children increased dramatically. The percentage of the children born in
London who died before the age of five
decreased from 74.5% in 1730–1749 to 31.8% in 1810–1829. Between 1700 and 1900,
Europe’s population increased from about 100 million to over 400 million.
(Wikipedia2)
The shift from the 1st phase (coal and steam era) to the 2nd
phase (electricity era) coincides with the British colonization of foreign
lands where they acquired many raw materials that needs to be processed in
large numbers.
However, industrialization has got a serious effect on the environment
while it strives to meet the needs of the growing population. Man through its
agent (Industries) contribute to more than 50% of the Environmental degradation
when he/she is trying to fetch raw materials, build industries and dispose
waste products. The final effect on the environment will include:-
Rapid
Industrialization versus Air Pollution
Air pollution involves
the release of chemicals and particulates into the air, and it can cause
problems varying from difficulty breathing to contamination of crops. The
increased rate of industrialization poses a major threat to the air quality. Most
the industries use environmentally unfriendly sources of energy like fossil
fuels, coal, wood fuel and others that releases high levels of Oxides to the
environment. Considering their sources of energy the industries that use wood
fuel contribute so much in logging. The indirect impacts will be the releases
of carbon to the atmosphere causing a significant increase in the Green houses
gases which causes global warming. In extreme cases, these gases may cause river, lakes and sea
levels to rise. This means that, as the globe continues to experience global
warming, chances of flooding increases. The worst pollutant in
low lying areas is Smog. Where
smog is produced abundantly, air quality deteriorates especially during hot
weather, and it is during this period that asthma cases rise. Industries
associated with massive smog emissions are those that operate in manufacturing
sectors. Example of the Donora Valley in Pennsylvania 1948.
The highest probable Top emitters of green house gases into
the atmosphere include; Power generation industries are major causes of global
warming. According to the year 2000 estimates, these industries emit more than
8000teragrams of carbon dioxide, and 3teragrams of methane. In total, this
industry alone accounts for 31% of greenhouse gases emitted annually. Second on
the list of industries causing global warming is the refineries. This
industrial sub sector emits more than 5000teragrams of carbon dioxide and
8teragrams of methane. Refineries alone accounts for 15% of greenhouses gases
emitted per year. Third on the list is the road sector. As countries continue
to develop, automobiles no longer become luxuries, but necessities. By the year
2005, the vehicles emissions accounted for almost the same percentage as the
refineries (15%) other contributing sectors are; coal mining and processing,
oil extraction and refining, international shipping, rail and non road
transportation and bio fuel production sectors (socyberty.com)
Industrialization and Land Pollution
The
industrial revolution brought with it some lucrative and convenient ways of
handling the Land. The Agricultural revolution intensified farming through use
of inorganic fertilizers and mechanization. Modern agriculture has embrace the
idea of going “green”, and has instead opted for inorganic means, has opposed
to the ancient organic ways of growing crops. The key issue why the world is
headed to an inorganic direction is to satisfy the growing population in terms
of food supply.
Industries
are the key players in production of Inorganic substances; fertilizers,
pesticides and fungicides. The industries are also linked with polluting the
crust through releasing of poisonous substances whether by accident or as a way
of disposing them. These industries produce on a large scale chemical
fertilizers, and commercial feeds that have short run benefits on both the
farmers and land. In the long run, all stakeholders stand to lose to due to the
distressing effects caused by agricultural and related industries. Prolonged
use of chemical fertilizers, pesticides and herbicides lead to massive land
pollution and reducing fertility of the same. Most of these chemicals are
highly leeched and others are non-biodegradable and constant use of it causes
accumulation in plant tissues.
Dumping
of industrial waste also contributes to land pollution. In 2007 alone,
Environment Protection Agency of the United Sates noted that there were more
than 10 million pounds of harmful pollutants dumped. Major pollutants
identified by this survey were heavy metals that comprise mainly of mercury,
lead and arsenic compounds.
Water Pollution versus
Industrialization
Ground water is mainly polluted
through leaching processes. Surface water on the other hand gets polluted
through a number of ways. One of the ways that rivers, lakes and seas, get
polluted is when sulfur oxides combine with moisture to form acid rain then
these flows into the water sources. Runoffs from polluted agricultural land,
also leads to water pollution. Other ways that surface water gets polluted is
through oil spills, water runoff from dumping sites and through deliberate
disposal of industrial waste into water bodies.
Conclusion
Although
modern man is justified to apply the current means of production and develop
the current technology to use in industries and in food production to increase
his food production, man is ignoring the fact that he plays a key role in the
environment and he has the mandate to take care of the environment.
Human
beings by his means through intensified means production due to rapidly growing
population and the nature of demands dictates that man must engage in
activities that expose the environment to a total risk of degradation.
In summary
increased population or over population causes environmental degradation not by
direct impact but through the activities that man undertake over the earth’s
surface both in marine and terrestrial lands that includes; Intensive
Agricultural activities, rapid growth of urban centers with unplanned
settlements and industrialization
Recommendation
Since mans
action on the environment is justified due to the fact that man needs to derive
source of livelihood, we are therefore left with no option as human beings and
especially as environmentalists to device environmentally friendly ways that
does not necessarily stop mans harm on the environment but means that reduce
the effect and foster sustainable development.
Some of
the ways might be; change in the means of Transport. This can be done by
encouraging man to use public means that uses less fuel does less emissions of Oxides into the Atmosphere. The
use of commercial means of Transport saves both the non-renewable sources of
Energy and also reduces the combustion of fossil fuels to produce petroleum
products.
Secondly,
we can adopt a culture of using renewable sources of Energy like solar energy
and wind energy. Less has been done to harness wind energy which is
eco-friendly type of energy.
Finally, we
should encourage the use recycling of wastes and plan for companies in such a
way that the waste products of one company becomes a raw material of another
company.
According
to the Population Policy for National Development(Kenya) Launched on 30th
October 2012 proposes that average Kenyan women gives birth to 2.6 Children over the reproductive age of 15
to 49 years currently the woman gives birth to an average of 4.6 children. The
policy further warns that the population will hit the 77Million mark by 2030
when the Kenya’s Economic blueprint, Vision 2030, expires-Daily Nation 31St
October 2012.
Therefore,
national family planning campaigns should be intensified so as to attain the
2.6. Children per woman between the ages of 15-45 years.
Awareness
creation should be also intensified in rural and urban areas/informal settlements
to curb the increasing population.
REFERENCES
1.
Balmford. A et al, Measuring the changing state of nature TRENDS in Ecology and
Evolution Vol.18 No.7 July 2003
2.
Central Statistical Organization,
(2000), “Compendium of Environment Statistics,” Ministry of Statistics and
Programme Implementation, Government of India, New Delhi.
3.
Cropper M., C. Griffiths (1999), “The
Interaction of Population Growth and Environmental Quality” American Economic
Review, 84:250-254
6.
The
United Nations International Strategy for Disaaster Reduction (UNISDR) (2009)
Terminology on Disaster Risk
7.
UNEP, 1999, “Unequal Impacts of
Environment Damage, “Human Development Report 1999, Oxford University Press,
New York.
8.
U.N HABITAT (1996), “An Urbanization
World. Global report on Human Settlement. Instanbul.
9.
UNEP,Global Environmental outlook (1999/2000)
No comments:
Post a Comment