Реферат: Urbanization

Introduction
Urbanization is one of the most controversial problems of modern society.
Although it is an essential process of social and economical development of
humans, it also the source of the problems that people never faced before.
Anyone familiar with the world development trends knows that nearly half of
the worldТs population lives in urban areas and the number are expected to
grow by 2% every year. Because of greater engagements in non-farm activities
and driven by financial or educational needs people shifts to cities, causing
the rapid growth of urban areas. Cities play not only the role of employment,
shelter and service but also play the role of center of culture, education
and portal to the rest of the world.
Although, cities and their ecology have a thousand years of evolving history,
the term Уurbanization and ecologyФ surprisingly only appeared very recently.
For example, term ФUrbanizationФ was born only in the middle of 19th 
century, when with the expansion of industry people started to move from rural
to urban areas causing vast pressure on the capacity of cities. Air pollution,
acid rain, and imbalance of ecology made the term Уecology of urbanizationФ
more and more relevant in 20th century and made the public pay more
attention to this issue. It is kind of scary to realize that this kind of
important issue is only a little bit older than me.
Modern urbanization process has tons of problems, starting with insufficient
housing and ending with global ecology impact. In this paper, I tried to
cover a little piece of the ecology problems that urban areas are facing
these days: air, water, waste and ecological footprint. The paper is designed
to cover the basic ideas of ecological impact and how significant it can be
if we donТt realize it soon.
     
Urbanization and ecology
Everybody knows the obvious correlation between urbanization and economic
development; some Asian countries rapidly developed during 70Тs and 80Тs, the
time when the large movement of population from rural to urban was recorded.
According to UN report, worldwide, cities produce on average 60 percent of a
countryТs GNP. Bangkok, for example, produces 40 percent of ThailandТs
output, whereas only 12 percent of its population lives in this city.  Cities
are undoubtedly the basis for any functioning economy and it will keep
remaining important in the future. As mentioned in the introduction, cities
are the centers of culture and economic prosper, but the mismanagement and
poor economical development can turn the cities into centers of unemployment,
poverty and pollution.
As the city grows it needs more lumber, more steel, more labor and more land.
They absorb the agricultural land for urban use, the forest for construction
and all sorts of raw materials for growth. A city the size of San Francisco
has more copper and aluminum than a medium size mine; more lumber than some
countries have in their forest. Cities behave like a giant growing monster,
eating and swallow everything round it, while at the same time spoiling and
wasting surrounding areas. High concentration of cars and industries causes
the air and water pollution, high demand produces extra wastes and high
density requires more land. In many cases cities are the only cause of the
instability of the sensitive ecosystem of the region.
Until recent time the false attitude was popular that only cities of
developed countries has an ecology problem. Breaking point was in 1972 when
UNТs Stockholm conference on ecology declared that ecology of urbanization is
one of the difficult problem almost in all countries, no matter where.
One of the reasons of environmental pollution in the developing countries is
weak legislation enforcement. Cheap production cost, weak legislation
enforcement and corrupted officials are the signs of easy money in developing
countries. As a result many corporations from developed countries moved their
production of hazardous and dangerous products in to third world. Instead of
paying millions of dollars for cleaning and security equipments, they are
enjoying a quite safe and cheap environment in hosting countries and harming
environment without even bothering about it. Most of these productions
usually located within the urban zones. For example, research done in
Nicaragua in 1980, found the source of mercury poisoning among the population
in capital city. Uncontrolled down throw of mercury by American corporation
leaded to enormous poising of environment. In fact the content of mercury in
the city water was 12 times higher than it was allowed in the US.
     
Air and water of condition of urbanization
     Air pollution
Under the term Уecological disasterФ we understand that one constant system
changes to another unstable system. For example, increase in average
temperature on Earth leads to melting of polar ice, which can have an
unpredictable consequence; or spread of the ozone hole can bring all sorts of
diseases or death to a many life forms. One or all of these disasters would
occur as the product of our activity if the countries wonТt pay enough
attention to greenhouse effect of emission.
Urban air pollution is one of the most important environmental problems. High
concentration of transportation, industry and people turns the city into
perfect polluter of the air. According the statistical data, the main sources
of air pollution are vehicle exhaust, industrial emissions, and domestic use
of wood, coal and refuse for heating and cooking. But in the city the lion
share of air pollution belongs to transportation. Vehicles contribute about
14% of total global air pollution but in big cities it can contribute up to
80% of the cityТs emission. There are about 600 million units of vehicles in
the world, and every type produces about 3-4 kg of carbon dioxide, more than
our nature can absorb.
In most European and North American cities, the concentrations of SO2 and
Suspended Particulate Matter (SPM includes dust, fumes, mists and smoke Ч SO2
and troposphere ozone) have decreased substantially in recent years. However,
in the US every second person has a car, about 170 million cars with the
population of 280 million people; high concentration of industry and
transportation turned the US into one of the biggest air polluters in the
world, even though the number is decreasing. The US account for 26% of the
total air pollution in the world.
The problem is not only in developed countries. In many developing countries,
rapid urbanization has resulted in increasing air pollution in many cities.
WHO air quality guidelines are often not met and, in mega cities such as
Beijing, Calcutta, Mexico City and Rio de Janeiro, high levels of Suspended
Particulate Matter (SPM) prevail. The result of air and water pollution is
chronic and infectious respiratory disease; water borne diseases; increased
mortality rates, particularly among children; and premature deaths Ц the
highest rate being among the poor. In Cairo, the leading polluted city, there
are about 10.6 million people with respiratory disorder (SEI 1999). Air
pollution is not only the cause of lung disease, but also has become the
cause of heard attacks, birth defects and cancer.
In developing countries, transportation is not the main source of air pollution.
For example China and India together have about 600 million bicycles and much,
much fewer cars. If in the US every second person has a car, in China only
every 79th person has a car, so the sources of pollution are
different. People move from rural to urban areas to find better job and a
better life, so many cities in China have a housing problem. Because the city
canТt offer decent housing, people live in small self-built shelters and
usually heating and cooking is done by burning a very low quality coal, because
it is the only cheap source of energy. Beijing is one of the air polluted
cities in the world and because of air pollution they have a desert 
problem. All green plants around the city are dead and any efforts to plant new
trees and grass have had a miserable result.
The geographical location plays not last role in the determination of air
pollution of cities. For example, some cities in South America, which are
located in high mountains have natural problem with free flow of air movement
that removes polluted air. Besides, the low oxygen concentration in high
mountain areas causes the partial burn of the fuel, which simply worsens the
situation. For example Mexico city, the second largest city in the world, has
a big problem with smog Ц dry, smoky fogs, which consist of carbon dioxide
and nitrogen dioxide. Sometimes the smog stays for few days in the city
without any movement, causing enormous harm to the health of citizens of
Mexico city.
     Water pollution
Water pollution problems vary in severity around the world, depending on
population densities, the types and amounts of industrial and agricultural
development, and the number and efficiency of waste treatment systems that
are used.
For a millennia, people have used water as a convenient sink into which to
dump wastes. The pollution comes from many sources, including untreated
sewage, chemical discharges, petroleum leaks and spills, and agricultural
chemicals that are washed off or seep downward from farm fields. In one area
after another, the amounts and types of waste discharged have outstripped
nature's ability to break them down into less harmful elements. Pollution
spoils large quantities of water which then cannot be used, or at best can be
used for restricted purposes only.
A growing number of regions face increasing water stresses because more
people are both polluting and demanding more water for all uses from a
renewable but finite resource. They are thus suffering from scarcities caused
by failure to adapt to the amount of water that is regularly made available
by rain and snowfall. Water demands are so high that a number of large rivers
decrease in volume as they flow downstream, with the result that downstream
users face shortages, and ecosystems suffer, both in the rivers and in
adjacent coastal areas.
Many underground water resources, known as groundwater, are being drained
faster than nature can replenish them. Intensive and misuse of underground
water leads to drainage of water recourses around the city, deserting the big
areas beyond the cities boundaries. In some cases, groundwater depletion
results in the land above aquifers sinking. Land subsidence caused by high
water withdrawals has been recorded in many countries, including Mexico, the
United States, Japan, China and Thailand, with the land sinking from 1 to 10
meters.
South and Southeast Asia are facing severe water pollution problems. Rivers
such as the Yellow (China), Ganges (India), and Amu and Syr Darya (Central
Asia) top the list of the worldТs most polluted rivers. In cities in the
developing countries of the region, most water bodies are now heavily
polluted with domestic sewage, industrial effluents, chemicals and solid
wastes. Most rivers in NepalТs urban areas have been polluted and their
waters are now unfit for human use, while drinking water in Katmandu is
contaminated with coliform bacteria, iron, ammonia and other contaminants.
There are estimates that in developing countries, which often lack the
resources to build and maintain sewage treatment a system, 90 per cent of
waste water is discharged without treatment. A UN study found that in Latin
America, virtually all domestic sewage and industrial waste is discharged
untreated into the nearest streams. In most areas, domestic sewage volumes
are far higher than those of industrial discharges. There were similar
findings from West Africa, where there were signs of shallow aquifers being
contaminated by the seepage of human wastes.
     
Waste management
Some estimates show that New York wastes round 24Т000 ton material everyday.
It contains metal, glass, plastics, paper, food and etc. It also includes
dangerous substances like mercury from battery, phosphate from bulbs and
other different type of toxic waste from paintings, detergents, home cleaners
and etc.
The sad fact is that wealthy city tends to use more energy and produce more
waste than similar developing countryТs cities. Developing countries trash
about 2-3 times less waste than developed country. To satisfy an average
costumer, for example, a company uses more packaging than it needed or more
advertisements than it requires, which in other words mean more waste. Among
the nations, the US produces the highest waste per person Ц 520 kg waste per
person a year; in comparison Norway, Spain, Nederland Ц 200-300 kg, African
cities Ц much less.
Depending on the country and its economic stand, there are different
approaches to the waste management. Rich and developed countries or countries
with scarce land supply use high tech processes to handle the waste. But on
opposite side, poor and developing countries are still using the simple
methods of waste discharge.
     Open Waste Area and Land Filling.
Until recent time, 90% of waste in US is used to bury. Open dumping takes
more space and more energy to handle it and usually becomes the shelter of
different type of leaving creatures; rats, mosquitoes, bags - the potential
carriers of diseases. The process of rotting of organic waste spreads strong
smell to surrounding area, and the wind disseminates the loose trashes. In
developed countries there are almost no open dumping areas nowadays (except
for solid waste), but in third world it is the only way of handling the
waste; cheaper and more convenient. The heartbreaking fact is that those open
waste areas, in third world, become shelter and the only source of income for
many poor people.
Ecological impact of open dumping is wide and significant. The content of
waste can be various, starting from usual organic waste and ending with heavy
chemical products, which can be dissolved by rain or snow water. It leaks to
underground water and can spread many miles away from the original source. In
the past, people used open dumping because most of the waste used to be
absorbed by the nature; wind, water, ground and sun dissolve the waste. But
with the advance of the technology many items just simply donТt dissolve
easily. For example, paper takes two to ten years to completely disappear,
cans Ц more than 90 years, filter from cigars Ц more than 100 years, plastic
bags Ц 200 years, plastic Ц 500 years, glass Ц 1000 years.
With the danger of heavy pollution many countries changed open dumping to
land filling. Waste problem was solved for a decade, no more headaches for
government.  But with more pollution of underground water and threat to
health, people realized the hidden danger. Nowadays, land filling is a very
sophisticated process; just simple burying turned into high technological
storage areas. In the US 20 years ago, simply bury of waste cost $2 per kg,
now cost round $100 per kg; burying one liter of organic dissolvent costs
more than its production and it has an increasing tendency. With production
of 160 million tons of waste every year, the US has not only the problem of
the expenditure, but also the rapid fill ups of land filling areas.
     Waste-to-energy
High-density areas like Europe donТt have much land to landfill so they
preferred to burn the waste instead of burying. The first systematic chain
furnace was tested in England in 1874. Burning decreases the size of waste
about 70 - 90 percent and ashes easily turn into construction materials. This
method was adapted on both sides of Atlantic Ocean; in Europe early, in America
little bit later. In the developed world waste burning is used for production
of electrical and steam energy, construction supplies and crude iron. For
example, the leading USТs waste company the УWaste Management Co.Ф produces
about 623 megawatts of energy every year, which is equivalent of supplying
550,000 homes with energy. According companyТs report:Ф . УWMФ has processed
over 100 million tons of municipal solid waste into energy since 1975, saving
more than 150 million barrels of oil while producing 50 billion kilowatt hours
of electricity.Ф
Burning the waste for a production of energy also has its downside. Waste
itself is a very difficult burning material. It requires special expensive
process to be burnt and not everywhere it repaid the expenditure. For example
Moscow had a problem when they tried to establish the new plant. Mayor of
Moscow agreed to put in budget to purchase of furnace from western countries
but refused to buy the cleaning equipment, because the emission cleaning
equipment cost almost the same price as the plant itself. Without the
cleaning equipment amount of carbon dioxide it excretes into the air is
enormous. Moscow has an air pollution problem without the waste burning plant
so the project was canceled.
Most of the third world burning plants work because of subsidies of
international organizations. But in many, many developing countries this
technology just simply didnТt find the usage. It is much cheaper just burning
the waste on open area than trying to turn into energy.
     Recycling
So far the most perspective management of waste known to people is recycling.
It doesnТt require much government subsidy, doesnТt pollute environment and
it is economically efficient. Sweden is one of the highest recyclers of thee
aluminum cans, 8 of 10 cans is recycled. Production of cans from recycled
material cost only 40% of its original cost. From recycled material produced
construction material, furniture, paper towels and all sorts of plastic
items. Besides of its economical meaning it has great positive impact on
environment; there are less need to cut the tree or explore the new mine. In
the US, nowadays, about 20 % of the waste is recycled.
     
The ecological footprint of Urbanization
Everybody, from a single individual to a whole city or country, has an impact on
the Earth, because they consume the products and services of nature. Their
ecological impact corresponds to the amount of nature they occupy to keep us
going. The definition of footprint is: "The ecological footprint 
is the corresponding area of productive land and aquatic ecosystems required to
produce the resources used, and to assimilate the 
wastes produced, by a defined population at a specified material
standard of living, wherever on Earth that land may
be located." If the footprint exceeds the available biologically
productive area of the country, it runs an ecological deficit, which in other
words the countryТs area alone cannot provide sufficient ecological services to
satisfy its populationТs current patterns of consumption.
London - with 12% of Britain's population covering 170,000 hectares - comes
to some 21 million hectares or 125 times the surface area of the city itself,
equivalent to the entire productive land in the UK. The city of Vancouver,
Canada, indicates that city appropriates the productive output of an land
area nearly 174 times larger that its political area to support its present
consumer lifestyle. Other researchers found that the aggregate consumption of
wood, paper, fiber and food by the inhabitants of 29 cities in the Baltic Sea
drainage basin appropriates an area 200 times larger than the cities
themselves. Footprint of the Netherlands appropriates between 100,000 sq.
kilometers and 140,000 square kilometers of agricultural land, mostly in the
third world, for food production alone, it is almost 3-4 times larger than
the actual land.
Scientists have calculated that a typical North American city with a
population of 650Т000 people would require 30Т000 km sq of land, an area
roughly the size of Vancouver Island in Canada, to meet its domestic needs
without including the environmental demand of industry and I believe that the
ecological footprint would be enormous. A similar sized city in India would
require only 2Т900 sq km.
Despite small size, few natural resources, and relatively large populations,
both Holland and Japan enjoy high material standards and positive current
accounts and trade balances as measured in monetary terms. However, our
analysis of physical flows shows that these and most other so-called
"advanced" economies are running massive, unaccounted ecological deficits
with the rest of the planet. The different data of different researchers
emphasizes that most developed countries are over-populated in ecological
terms - they could not maintain themselves at current material standards if
forced by changing circumstances to live on their remaining endowments of
domestic natural capital.
     
Conclusion
Researchers like to characterize humanity's impact on the environment through
three factors: population, consumption and technology. Someone said:Ф The
pollution problem is a consequence of over populationФ. The humanity almost
doubled within the century and soon we are going to double again, no wonder
that we are facing the pollution problems. There are not much can be done
about population growth, because we all have the freedom of living and
breading. Everyone would like to leave behind the posterity. So maybe we must
concentrate on cutting back on consumption. IТm not saying that we must give
up all the comfort that our modern world offers to us but at least we must
try to use fewer, like saving the energy by turning off the unused electrical
equipment or thinking twice before buying the co-called transportation УSUVФ
which travels only eleven miles on one gallon of gas, which is insane. And
finally, we must try to develop our technology on high level and share with
others. More efficient and safe technology is our last hope on better
environment. Imagine, what will happen if all transportation will work on
battery or by the wind. It is so exciting to think about all the benefits
that humanity can derive from it.
Urbanization will continue to play a leading role in the economy, environment
and peopleТs life. The challenge is just to learn how to live with
urbanization while using its benefits and guiding undesirable and negative
impacts in manageable direction.