Реферат: Urbanization

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 world’s 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 “urbanization and ecology” surprisingly only appeared very recently.

For example, term ”Urbanization” 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 “ecology of urbanization”

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 don’t realize it soon.

Urbanization and ecology

Everybody knows the obvious correlation between urbanization and economic

development; some Asian countries rapidly developed during 70’s and 80’s, 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

country’s GNP. Bangkok, for example, produces 40 percent of Thailand’s

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

UN’s 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 “ecological disaster” 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 won’t 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 city’s 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 — 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 – 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

can’t 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 – 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 world’s 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 Nepal’s 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 24’000 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 country’s 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 – 520 kg waste per

person a year; in comparison Norway, Spain, Nederland – 200-300 kg, African

cities – 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 don’t dissolve

easily. For example, paper takes two to ten years to completely disappear,

cans – more than 90 years, filter from cigars – more than 100 years, plastic

bags – 200 years, plastic – 500 years, glass – 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 don’t 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 US’s waste company the “Waste Management Co.” produces

about 623 megawatts of energy every year, which is equivalent of supplying

550,000 homes with energy. According company’s report:” . “WM” has processed

of electricity.”

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 didn’t 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 doesn’t require much government subsidy, doesn’t 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 country’s area alone cannot provide sufficient ecological services to

satisfy its population’s 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 650’000 people would require 30’000 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 2’900 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:” The

pollution problem is a consequence of over population”. 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. I’m 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 “SUV”

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 people’s 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.