Most of the
energy we use today comes from fossil fuels. Coal, oil, and natural
gas are all fossil fuels created several millions of years before
by the decay of plants and animals. These fuels lie buried between
layers of earth and rock. While fossil fuels are still being created
today by underground heat and pressure, they are being consumed
much more rapidly than they are created. For that reason, fossil
fuels are considered as non-renewable; that is, they are not replaced
as soon as we use them. So, we will run out of them sometime in
the future.
Moreover
burning fossil fuels leads to pollution and many environmental
impacts. Because our world depends so much on energy, we need
to use sources of energy that will last forever. These sources
are called renewable energy. Moreover these renewable energy sources
are much more environmentally friendly than fossil fuels when
they are burned.
Among fossil fuels somehow special character has uranium-nuclear
fuel which can be exhausted in less than 100 years, but in so
called breeder reactors it can multiply and last much more. Nevertheless
problems with radioactive waste, which will present a danger for
millions of years and the the impact of accident in chernobyl,
which showed a risk connected with nuclear energy, most governments
in industrialised world are now abandoning nuclear power completely.
This development continues despite the fact that nuclear energy,
which produce almost zero emissions of greenhouse gases, can be
somehow a solution to global climate change (see bellow).
Emissions of greenhouse gases are now recognised as the most important
force behind the efforts to decrease consumption of fossil power.
The main problem isn’t that we use energy, but how we produce
and consume energy resources. As long as we continue to cover
our energy needs primarily by combustion of fossil fuels or nuclear
reactions, we are going to have the problems, the environmental
impacts, social and sustainability problems. What we really need
are energy sources that will last forever and can be used without
pollution of the environment.
Energy
consumption – sustainability problem
Each year, the equivalent of approx. 10 000 million tons of coal
is consumed on earth as energy. About 40 % from this is based
on oil and together with coal and natural gas more than 90 % of
the total energy consumption result from carbon atoms in these
fossil fuels. The consequence will be a global warming (greenhouse
effect) and the lack of resources in the future
.
Ancient discovery
of fire and the possibility of burning wood made available, for
the first time, fairly large amount of energy for mankind. Later
(4000 and 3500 years b.c.) After the first sailing ships and windmills
were developed and the use of hydropower began via water mills
or irrigation systems, cultural development began to accelerate.
For several thousands years human energy demands were covered
only by renewable energy sources – sun, biomass, hydro and
wind power. It was only until the start of industrial revolution
and the ability to transform heat into motion, when energy consumption
and industrial development accelerated rapidly.
The industrial
revolution was a revolution of energy technology based on fossil
fuels. This occurred in stages, from the exploitation of coal
deposits to oil and natural gas fields on a global scale. It has
been only half a century since nuclear power began being used
as an energy source. After this fossil-based era world nears the
beginning of another major transition, away from fossil fuels
and towards renewable energy sources once again.
Fundamental shift in the energy picture can be found in the enormous
increase of energy demand since the middle of the last century.
That increase is the result not only of industrial development
but also of population growth. World population grew 3.2 times
between 1850 and 1970, per-capita use of industrial energy increased
about 20-fold, and total world use of industrial and traditional
energy forms combined increased more than 12-f old
Today fossil fuels such as coal, oil and natural
gas account for 90% of total primary energy supply. Estimated
total world consumption of primary energy, in all forms (including
non-commercial fuels like biomass), is approximately 400 ej per
year, equivalent of some 9500 million tonnes of oil (mtoe) per
year.
Annual world primary energy consumption,1992 by source
.
Fuel Source
Consumption
In EJ
Consumption
In Mtoe
Oil
131
3128
Coal
91
2164
Natural Gas
75
1781
Biomass
55
1781
Hydro
24
661
Nuclear
22
532
TOTAL
398
9476
Assuming a world population of about 5300 million in that year,
this gives an annual average fuel use for every person in the
world equivalent to about 1.8 tonnes of oil. These figures include
all fuel used by industry, commerce, households etc. They also
include large quantities of wood and other biological fuels used
mostly in developing countries. Moreover, the figures are averages
over the world’s population, and concealed tremendous differences
between different regions.
Fuels are used per person at an average rate in developed countries
which is more than six times that in the developing countries.
It can be seen from the following table that the developed countries
use nearly twice as much fuel as less developed countries, even
though they have less than a third of their population.
Energy consumption in developed and developing countries
.
The magnitude of energy problem that may face future generations
can be illustrated by the simple calculation. The population of
the world in 1990 was approximately 5 billion people. The UN estimates
of population trends show it continuing to increase to around
8 billion by 2025, but stabilising towards the end of the next
century at somewhere between 10 and 12 billion people. Most of
that increase will be in the less developed countries.
According to the US DOE (department of energy) outlook for energy
use throughout the world continues to show strong prospects for
rising levels of consumption over the next two decades, led by
growing demand for end-use energy in asia. World energy demand
in 2015 is projected to reach nearly 562 quadrillion british thermal
units (btu). The expected increment in total energy demand between
1995 and 2015 - almost 200 quadrillion btu - would match the total
world energy consumption recorded in 1970, just before the energy
crisis of 1973.
Two-thirds of all energy growth will occur in developing economies
and economies in transition, with much of that growth concentrated
in asia. Energy growth in the developing countries of asia is
projected to average 4.2 percent per year, compared with 1.3 percent
for industrialized economies. The U.S. Growth rate is expected
to average only about 1 percent per year. As recently as 1990,
U.S. Energy consumption exceeded total consumption in the nations
of developing asia by 33 quadrillion btu. By 2015, energy use
in developing Asia is expected to exceed U.S. Consumption by 48
quadrillion btu.
According to the report of US DOE by 2015, oil use is expected
to exceed 100 million barrels per day, a consumption rate 50 per
cent greater than in 1995. Oil trading patterns are expected to
shift markedly as oil consumption in asia pacific areas far outpaces
domestic production gains, leading to a large increase in imports
from middle east suppliers. World-wide, coal use is projected
to exceed 7.3 billion tons by 2015, compared with 5.1 billion
tons in 1995. Growth in coal use will be regionally concentrated,
occurring for the most part in india and china.
Natural gas is expected to have the highest growth rate among
fossil fuels, at 3.1 percent a year, gaining share relative to
oil and coal.
By 2015 natural gas consumption on a btu basis will exceed the
total oil consumption recorded for 1995, at a level equivalent
to two-thirds of the oil consumption projected for 2015. Natural
gas consumption in 1995 was only about 55 percent of oil consumption.
According to us doe prediction only about 8 percent of projected
growth in energy demand over the next two decades will be served
by non-fossil fuel sources. In fact, the non-fossil (commercial)
fuel share of world energy consumption declines from 15 percent
to 12 percent over the projection period. Thus, world carbon emissions
are likely to increase by 3.7 billion metric tons, or 61 percent,
over the 1990 level by 2015. The climate change convention of
1992 commits all signatories to search for and develop policies
to moderate or stabilize carbon emissions.
However, even if all the developed countries were able to achieve
stabilization of their emissions relative to 1990 levels, overall
world carbon emissions would still rise by 2.5 billion metric
tons over the next two decades.
Per capita energy use in the world’s industrialized economies,
which far exceeds the levels in newly emerging economies, is expected
to change only moderately in the next two decades. In some emerging
economies (for example, india and china), per capita energy use
may double. Even with such growth, however, average per capita
energy use in the developing countries will still be less than
one-fifth the average for the industrialized countries in 2015.
In the longer term, consumption of oil as the principal source
of commercial energy today, will start to decline after the transition
phase (between 2020 and 2060). It is expected that natural gas
will continue to be used as long as price and availability are
satisfactory but as reserves reduce or prices rise coal (which
is usually less expensive than natural gas and its international
prices are unlikely to rise) will command a greater proportion
of the market. To maintain energy levels and because of world-wide
environmental concerns some experts predict that coal will have
to be utilized cleanly, where gasification process will be the
most environmentally friendly way of its future utilization.
The transition to a sustainable energy system requires that share
of renewable energy sources will continually grow. Renewables
combined with a system of new technologies, can contribute to
a considerable extent to energy requirements in the time horizon
beyond 2020. Report for the un solar energy group for environment
and development suggests that using technology already on the
market or at the advanced engineering testing stage, by the middle
of the next century renewable energy sources could account for
60 percent of the world’s electricity market and 40 percent
of the market for fuels used directly.
Fossil fuels are valuable natural energy sources which required
several millions of years for their creation but are now rapidly
being depleted. The prominent worry that fossil fuels will run
out was reported almost 30 years ago by the influential book limits
to growth. This book reported a series of computer simulations
of future resource use in which world fuel consumption continued
to rise exponentially. The predicted result was an ultimate collapse
in fuel supplies, regardless of the amount of fuel assumed to
be available. These fears came into sharp focus in the 1973 fuel
crisis, when the member nations opec were able for the first time
to co-ordinate their policies and raised the price of oil dramatically.
One of the factors which gave the opec states the power to exert
their influence so strongly was that the usa, formerly a major
exporter of oil , had become an importer. United states had used
up most of the easily obtainable oil from the texas oil fields.
The shortage expected in the dramatic concerns of those days do
not seem imminent at present. The general principle that the amount
of fossil fuels remaining is ultimately limited and cannot last
for ever is obviously true, but estimating how long they will
last is not a simple process. In any year, newly reported figures
for „proven reserves“ of oil, gas and coal are available.
Proven reserves are generally taken to be those quantities which
geological and engineering information indicate with reasonable
certainty can be recovered in the future from known deposits under
existing economic and operating conditions.
A useful figure of the merit for fuel reserves is the reserve/production
ratio. If the proven reserves remaining at the end of any year
are divided by the production (consumption) in that year, the
result is the time that those remaining reserves would last if
production were to continue at the then-current level.
According to the british petroleum statistics the reserves/production
(r/p) ratio of the world’s fossil resources is estimated
as
:
FUEL R/P RATIO
Oil 40 Years
Natural Gas 62 Years
Coal 224 Years
Like the fossil fuels, uranium is also one of the depletable
natural resources. If uranium is only used in a once-through cycle
where it is burned in a reactor only once and disposed as a waste
thereafter, confirmed reserves are destined to be depleted in
the next 60 years.
The reserves/production ratio for any region also gives an indication
of the dependence of that area on more favoured regions. For example,
for oil, the reserve/production ratio was less than 10 years for
western europe and for north america it was about 25 years. Obviously,
both regions would be in dire straits if they could not import
oil from middle east, where the ratio is nearly 100 years. The
middle east has some 60 % of the world’s reserves of oil,
and saudi arabia alone contains about 25 %.
For gas the situation is somewhat different, because of the massive
reserves in the former soviet union. This region holds some 40
% of the worlds reserves of gas, and another 40% of gas is in
the opec region. The world as a whole is greatly dependent upon
a limited number of regions which have most of the reserves. The
reserve/production ratio for coal are much larger and much more
evenly distributed. Unfortunately, coal has disadvantages compared
to oil and gas. Coal burning creates more co2 per unit of energy
released than is the case with gas and oil, and more sulphur dioxide
and nitrogen oxides.
At some moment during the next five years, we will have consumed
more than one half of the total usable fossil oil on earth. To
date, we have extracted 807 billion barrels of crude oil. Only
an estimated 995 billion barrels remain that can be extracted
at current production costs. If the world-wide rate of oil consumption
remained a constant 24 billion barrels of oil per year, we would
run out of oil in 2040. But consumption is not static-it is increasing
by about 2 percent per year. It seems clear that demand for oil
will overshoot supply well before 2040. At some point between
2010 and 2025, all fuel from fossil oil will be too expensive
for the average consumer to afford. Exactly when that point comes
will depend largely on the actions of middle eastern countries.
Exploration for oil, the most important fossil fuel today, is
a very expensive business. The amount of exploration is dependent
upon economic conditions, particularly the price of oil, and upon
political conditions. The world’s proven reserves of oil
have increased from some 540 billion barrels in 1969 to just over
1000 billion barrels in 1992, but this does not mean that potential
reserves are unlimited.
The earth has been surveyed in great detail by the oil companies,
and the easiest, cheapest and most promising reservoirs have all
been found. Except for the huge pool of oil in the middle east,
the world’s most readily exploitable sources of oil and
gas have been used up. It is only because of this that such difficult
sources of oil as the north sea and alaska have become economically
viable - that is, the price of oil has risen enough to make them
worth exploiting. In physical terms, the more difficult reserves
require deeper holes or extraction in more difficult environments,
and the use of more materials and effort to supply the same result.
In 1970, world-wide annual consumption of natural gas was 850
billion cubic meters. Today, annual consumption is over 2000 billion
cubic meters and is increasing at 3.5 percent per year. A 3.5
percent annual increase in consumption will deplete natural gas
reserves by 2050. However, the increase in consumption of natural
gas is accelerating at an astonishing rate.
Cheap supplies of natural gas will be depleted by 2040. This
fact is recently completely neglected by power companies which
are building new natural gas power stations to give customers
in their area cheaper and cleaner electricity. Experts believe
that by 2010, the supply of electricity from new natural gas power
facilities will jump to 100,000 megawatts in usa alone. Natural
gas power plants are attractive to investors. They have relative
short pay back time (an average six year in the usa) and can produce
electricity for a cheap rate of two to three us cents per kilowatt-hour.
It seems clear that the demand for natural gas fuel will increase
in the near future but will slow down in the second half of the
next century.
Most important environmental impacts caused by energy sources are
global climate change and acid rain – both of which have the
origin in the combustion of fossil fuels and lead to global or transboundary
effects.
Climate
Change
During the last few decades, concern has been growing internationally
that increasing concentrations of greenhouse gases in the atmosphere
will change our climate in ways detrimental to our social and
economic well-being. Climate change or global warming means a
gradual increase in the global average air temperature at the
earth’s surface. Abundant data demonstrate that global climate
has warmed during the past 150 years.
The majority of scientists now believe that global warming is
taking place, at a rate of around 0,3 ?C per decade, and that
it is caused by increases in the concentration of so-called “greenhouse
gases” in the atmosphere. The most important single component
of these greenhouse gas emissions is carbon dioxide (co2). The
major source of emissions of co2 are power plants, automobiles,
and industry. Combustion of fossil fuels contributes around 80
percent to total world-wide anthropogenic co2 emissions.
Another source is global deforestation. Trees remove carbon dioxide
from the air as they grow. When they are cut and burned that co2
is released back into the atmosphere. Massive deforestation around
the globe is releasing large amounts of co2 and decreasing the
forests’ ability to take co2 from the atmosphere.
The second major greenhouse gas is methane (ch4). It is a minor
by-product of burning coal, and also comes from venting of natural
gas (which is nearly pure methane).
Different fossil fuels produce different amounts of co2 per unit
of energy released. Coal is largely carbon, and so most of its
combustion products are co2. Natural gas, which is methane, produces
water as well as co2 when it is burned, and so emits less co2
per unit of energy than coal. Oil falls somewhere between gas
and coal in terms of co2 emissions, as it is made up of a mixture
of hydrocarbons. The amount of co2 produced per unit of energy
from coal, oil and gas is in the approximate proportion of 2 to
1,5 to 1. This is one of the reasons why there is a move towards
greater use of natural gas instead of coal or oil in power stations,
despite the much greater abundance of coal.
The earth’s atmosphere is made up of several gases, which
act as a “greenhouse”, trapping the sun’s rays
as they are reflected from the earth’s surface. Without
this mechanism, the earth would be too cold to sustain life as
we know it. Since the industrial revolution, humans have been
adding huge quantities of greenhouse gases, especially carbon
dioxide (co2) to the atmosphere.
More greenhouse gases means that more heat is trapped, which
causes global warming. By burning coal, oil and natural gas increases
atmospheric concentrations of these gases. Over the past century,
increases in industry, transportation, and electricity production
have increased gas concentrations in the atmosphere faster than
natural processes can remove them leading to human-caused warming
of the globe.
Recently, alarming events that are consistent with scientific
predictions about the effects of climate change have become more
and more commonplace. The global average temperature has increased
by about 0.5° c and sea level has risen by about 30 centimetres
in the past century. 1998 was the hottest year since accurate
records began in the 1840s, and ten of the hottest years have
occurred during the last 15 years.
Official confirmation of global climate change came in 1995, when
the un intergovernmental panel on climate change (ipcc), an officially
appointed international panel of over 2,500 of the world’s
leading scientific experts, found that “… The balance
of the evidence suggests a human influence on the global climate.”
It has been concluded that the temperature on this planet during
this century has steadily risen with the higher concentration
of carbon dioxide, at a rate in accordance with theoretical prediction
and that this is an effect which would continue to raise the temperature
for another 75 years even if carbon dioxide emission was stopped
today.
The following are events which consistent with scientists predictions
of the effects of global warming. The past two decades have witnessed
a stream of new heat and precipitation records. Glaciers are melting
around the world. There has been a 50 percent reduction in glacier
ice in the european alps since 1900. Alaska’s columbia glacier
has retreated more than 12 kilometres in the last 16 years while
temperatures there have increased. A huge section of an antarctic
ice shelf broke off. Some scientists think this may be the beginning
of the end for the larsen b ice shelf, which is about the size
of connecticut. Severe floods like the devastating midwestern
floods of 1993 and 1997 are becoming more common. Infectious diseases
are moving into new areas.
Corresponding with global warming, sea levels have risen, and
climatic zones are shifting. All these changes exemplify the environmental
impact of global climate change. Global warming and climate change
pose a serious threat to the survival of many species and to the
well-being of people around the world.
The ipcc estimates that air temperatures will increase by another
1-3.5°c, and sea levels may rise by up to 1 meter over the
next 100 years. Changes of this magnitude will affect many aspects
of our lives. Here are some of them :
more people will die from heat stress. Severe heat waves like
the one that killed hundreds of people in chicago in 1995 will
become more frequent. Children and the elderly are most vulnerable
to heat stress.
Tropical diseases will spread. Infectious diseases such as malaria,
dengue fever, encephalitis, and cholera that are spread by mosquitoes
and other disease-carrying organisms which thrive in warmer climates
will be able to advance into new areas. This will lead to more
incidents like malaria outbreaks in new jersey and dengue fever
in texas.
Seas level will rise. Rising sea level will erode beaches and
coastal wetlands destroying essential habitat and leaving coastal
areas more prone to flooding. Just a 50 centimetres sea level
rise would double the global population at risk from storm surges.
The water cycle will be disrupted. As the water cycle intensifies,
some areas will experience more severe droughts, while others
will have increased flooding. This variability will stress areas
that are already prone to water quality and quantity problems.
Food crop yields will be affected. A warmer climate will increase
irrigation demands and the range of certain pests, but it will
also extend the growing season for some areas. While some countries
will find their food production increases with a warmer climate,
the poorest countries that are already subject to hunger are likely
to suffer significant decreases in food production.
Endangered species will suffer. Some of the most vulnerable plants,
animals, and ecosystems will suffer major changes. Ten species
at high risk from global warming are: giant panda, polar bear,
indian tiger, reindeer, beluga whale, rockhopper penguin, snow
finch, harlequin frog, monarch butterfly, and grizzly bear.
Coral reefs will be harmed. Overheating of ocean waters, as a
result of global warming, can lead to coral bleaching, which is
a breakdown of the complex biological systems that corals have
evolved in order to survive .
Another side effect of fossil fuels combustion and resulting emissions
of pollutants is acid rain (or acid deposition). In the process
of burning fossil fuels some of gases, in particular sulphur dioxide
(so2) and nitrogen oxides (nox) are created. Although natural
sources of sulphur oxides and nitrogen oxides do exist, more than
90% of the sulphur and 95% of the nitrogen emissions occurring
in north america and europe are of human origin. Once released
into the atmosphere, they can be converted chemically into such
secondary pollutants as nitric acid and sulphuric acid, both of
which dissolve easily in water. The result is that any rain which
follows is slightly acidic. The acidic water droplets can be carried
long distances by prevailing winds, returning to earth as acid
rain, snow, or fog.
Natural factors such as volcanoes, swamps and decaying plant life
all produce sulphur dioxide, one of the contributing gases to
acid rain. These natural occurrences form some kind of acid rain.
There are also some cases where acid rain may be produced naturally,
which is also bad for the environment but occurs in much lower
amounts and quantities than that of those found in urban areas.
Between the 1950’s and the 1970’s the rain over europe
increased in acidity by approximately ten times. In the 1980’s
however, acidity levels decreased, but although many countries
have started to do something about pollution that causes acid
rain, the problem is not going away.
Acid rain is often phrased as “acid precipitation”.
On the ph scale, rain usually measures 5.6. Anything below this
measurement is said to be acidified rainfall. The chemical equation
for acid rain is as follows :
Water solutions vary in their degree of acidity. If pure water
is defined as neutral, baking soda solutions are basic (alkaline)
and household ammonia is very basic (very alkaline). On the other
side of this scale there are ascending degrees of acidity; milk
is slightly acidic, tomato juice is slightly more acidic, vinegar,
lemon juice is still more acidic, and battery acid is extremely
acidic. If there were no pollution at all, normal rainwater would
fall on the acid side of this scale, not the alkaline side. Normal
rainwater is less acidic than tomato juice, but more acidic than
milk. What pollution does is cause the acidity of rain to increase.
In some areas of the world, rain can be as acidic as vinegar or
lemon juice.
This acid rain can cause damage to plant life, in some cases seriously
affecting the growth of forests, and can erode buildings and corrode
metal objects. The primary component involved in corrosion is
acid rain. It is estimated that the damage to metal buildings
alone amounts to about 2 billion dollars yearly. The highest emissions
of sulphur come from those sectors, which use the most energy
and the highest sulphur-content fuels, that is solid fuels and
high sulphur heavy fuel oil. Solid fuels are the most polluting
fossil fuels locally and globally. These fuels range from hard
coals to soft brown coals and lignites, which have high proportion
of combustion waste and pollutants such as sulphur, heavy metals,
moisture and ash content.
One of the major problems with acid rain is that it gets carried
from a mass acid rain producing area to areas that are usually
not as badly affected. Tall chimneys that are built to ensure
that the pollution that is produced by factories is taken away
from nearby cities, puts the pollution into the atmosphere. When
these particles get picked up by the moisture in the air, they
form acids. As a result they become a part of the clouds. Then
these clouds get carried off by wind, which means that when the
rain falls it may be a long distance away from where the acidic
particles were picked up from. An example of this would be central
and eastern europe and scandinavia. Sweden suffer from acid rain
because of huge sulphur emissions from eastern european power
plants with low emission standards and because of wind blowing
the particles over to their country.
When acid rain falls, it can effect forests as well as lakes and
rivers. In many countries around the world, trees are suffering
greatly because of the results of acid rain. A lot of trees are
losing their leaves and thinning at the top. Some trees are affected
so severely that they are dying. To grow, trees need healthy soil
to develop in. Acid rain is absorbed into the soil making it virtually
impossible for these trees to survive. As a result of this, trees
are more susceptible to viruses, fungi and insect pests and they
are not able to fight them and they then die.
Acid rain can have a severe effect on buildings. Materials such
as stone, stained glass, paintings and other objects can be damaged
or even destroyed. It slowly, but gradually, eats away at the
material until there is virtually nothing left. Building materials
crumble away, metals are corroded, the colour in paint is spoiled,
leather is weakened and crusts form on the surface of glass. In
certain parts of the world many famous and ancient buildings are
been damaged by acid rain. St. Paul’s’ cathedral in
london is having it’s stone work eaten away by acid rain.
In rome the michelangelo statue of “marcus aurelius”
has been removed to protect it from air pollution.
Acid rain damages soil when it falls onto the ground. It also
has a noticeable effect when it falls directly into or is washed
into lakes. Most of the animal and plant life in clean lakes and
rivers are unable to tolerate acid rain. They can be poisoned
by substances that the acid washes out from the surrounding soil
into the water. All over the world there are examples of plant
life and animal life suffering a lot or even not surviving the
effects of acid rain. For example, thousands of lakes in scandinavia
are without any kind of life, whether it be animal or plant. Over
the past years they have received a lot of acid rain as a result
of the wind blowing the particles into their country form places
such as england, scotland and eastern europe. Since the 1930’s
and 40’s some swedish lakes have increased acidic levels
in their rain water by up to 1,000 times.
The interactions between living organisms and the chemistry of
their aquatic habitats are extremely complex. If the number of
one species or group of species changes in response to acidification,
then the ecosystem of the entire water body is likely to be affected
through the predator-prey relationships of the food web. At first,
the effects of acid deposition may be almost imperceptible, but
as acidity increases, more and more species of plants and animals
decline or disappear.
As the water ph approaches 6.0, crustaceans, insects, and some
plankton species begin to disappear. As ph approaches 5.0, major
changes in the makeup of the plankton community occur, less desirable
species of mosses and plankton may begin to invade, and the progressive
loss of some fish populations is likely, with the more highly
valued species being generally the least tolerant of acidity.
Below ph of 5.0, the water is largely devoid of fish, the bottom
is covered with undecayed material, and the near shore areas may
be dominated by mosses.
Terrestrial animals dependent on aquatic ecosystems are also
affected. Waterfowl, for example, depend on aquatic organisms
for nourishment and nutrients. As these food sources are reduced
or eliminated, the quality of habitat declines and the reproductive
success of the birds is affected. Both natural vegetation and
crops can be affected.
Human Health
We eat food, drink water, and breathe air that has come in contact
with acid deposition. Canadian and u.s. Studies indicate that
there is a link between this pollution and respirator problems
in sensitive populations such as children and asthmatics. Acid
rain also makes some toxic elements, such as aluminium, copper,
and mercury more soluble. Acid deposition can increase the levels
of these toxic metals in untreated drinking water supplies. High
aluminium concentrations in soil can also prevent the uptake and
use of nutrients by plants.
Beside greenhouse gases, so2 and nox emissions that cause acid
rain, emissions of particulate matter contribute to bad air quality.
Fuel combustion is the most important source of anthropogenic
nitrogen oxides, while fuel combustion and evaporative emissions
from motor vehicles are the main sources of anthropogenic volatile
organic compounds (vocs).
Motor vehicles account for a considerable fraction of the total
emissions of nitrogen oxides and vocs in europe and north america.
Nox emissions also contribute to the formation of tropospheric
photochemical oxidants. Photochemical oxidants, especially ozone
(o3), are among the most important trace gases in the atmosphere.
Their distributions show signs of change due to increasing emissions
of ozone precursors (nitrogen oxides, or vocs, methane and carbon
monoxide).
According to world health organisation air quality guidelines
for ozone limit values are frequently exceeded in most parts of
developed countries. In the lower troposphere, close to the ground,
ozone is a strong oxidant that at elevated concentrations is harmful
to human health, materials and plants. In the upper troposphere,
ozone is an important greenhouse gas and contributes greatly to
the oxidation efficiency of the atmosphere.
There are reported several ozone and other photochemical oxidants
effects on human health, materials, and crops. Increased ozone
level can cause premature ageing of lungs and other respiratory
tract effects like impaired lung function and increased bronchial
reactivity. Increased incidence of asthmatic attacks, and respiratory
symptoms, have been observed. Ozone contributes to damage to materials
such as paint, textile, rubber and plastics. In the case of crops
and some sensitive natural types of vegetation or plant species,
exposure to ozone will lead leaf to damage and loss of production.
Other photochemical oxidants cause a range of acute effects including
eye, nose and throat irritation, chest discomfort, cough and headache.
As a second consequence of increases in global trace gas emissions,
a further decrease is expected to occur of the self-cleansing
capacity of the troposphere. This would result in longer atmospheric
residence times of trace gases and, consequently, an enhanced
greenhouse effect and an increased influx of ozone-depleting trace
gases into the stratosphere.
Heavy metals like arsenic (as), cadmium (cd), mercury (hg), lead
(pb) and zinc (zn) are also released during fuel combustion. Lead
pollution as the result of road traffic emissions have decreased
markedly since early 80s due to increased consumption of unleaded
gasoline and use of catalysts in cars. Nevertheless this sector
remains the main source of lead in atmosphere.
Beside emissions of pollutants there are also some other impacts
of fossil fuel combustion on local environment. Here microclimatic
impacts like origination of fogs, less sunshine etc. Are the results
of large amounts of water vapour effluents from cooling towers
of power plants.
Damage caused by the transport of oil is related to the pollution
of the seas. Here as the scale of oil production has increased
during the twentieth century, the quantity of oil transported
around the world, most of it by the sea, has also increased. To
cope with this increase, in a highly competitive market, the size
of oil tankers has increased to the point where they are by far
the largest commercial ships. Even in routine operation, this
results in large quantities of oil being released into the seas.
The tankers fill up with water as ballast for return journeys.
When this is emptied, significant quantities of oil are released
as well. Despite the fact that the transport of oil is generally
a safe industry, the scale of it, and the size of tankers, means
that when accidents do occur they have a large effect. Although
the number of accidents is small in proportion to the number of
tanker journeys, thousands of minor incidents involving oil spills
from tankers, and oil storage facilities occur annually.
Between 1970 and 1985 there were 186 major oil spills each involving
more than 1300 tonnes of oil. In 1989, the tanker exxon valdez
ran aground off alaska, releasing 39.000 tonnes of oil to form
a slick covering 3.000 square kilometres and causing widespread
environmental damage. People usually tend to think of the seas
as a vast reservoir which can soak up limitless quantities of
whatever we put into it. In fact, the scale of pollution from
oil is such that clumps of floating oil are now common almost
anywhere in the world’s oceans.
Beside environmental problems associated with large-scale use of
fossil and nuclear fuels and the problems with sustainability there
are also social problems arising from present trends of energy utilization.
Political
And Economic Problems
In the earlier stages of the industrial revolution, fuel sources
were local and widely distributed. Industrial activity tended
to grow in areas where local sources of coal were available. As
the transport associated with industrialisation spread and developed,
fuels began to be transported from more and more distant places.
Now, with the most accessible sources of oil and gas depleted,
fuels are transported around the world from small number of major
producing areas.
The result is that the major industrial nations have become
dependent upon supplies from those producing nations, in particular
oil from the middle east, and are highly vulnerable to disruption
of these supplies. This vulnerability and dependence has been
a major factor shaping world politics. A series of major economic
and political crises has resulted from sues crisis in 1956 to
the 1970s, oil crisis to the gulf war in early 1990s.
Since the producing nations are generally weak militarily and
the consuming nations are generally stronger, latter are under
pressure to dominate the former economically, politically and
if necessary, militarily to maintain access to oil (most important
fuel today).
A related aspect of vulnerability in the present form of industrialisation
is the centralized nature of fuel production and distribution.
Electricity is generated in relatively few, very large power stations,
and distributed through the country. Oil is imported in giant
tankers, and converted to fuel in large refineries for further
distribution. Concerns have been expressed that these large, vital
installations offer potential target for terrorists or military
opponents. As has been seen in recent years in the middle east
(gulf war), the result can be massive ecological damage as well
as economic devastation. The normal response to such vulnerability
is to put greater resources into security and to increased level
of protection.
High level of centralisation leads also to problems with employment.
Decentralized energy production and utilization which is the case
of renewable energy sources can create much more new jobs than
centralized fossil fuel installations.
Nuclear weapon proliferation is one of the biggest threat to the
world peace today with several countries already in or trying
to be a member of “nuclear club”. In developed countries
nuclear electricity industries grew out of nuclear weapons development.
The earliest nuclear reactors were built to produce material for
nuclear bombs. There has always been a close connection between
the two terms of the technology used, so that military spending
on research and development for nuclear weapons technology has
in effect been a major subsidy for civilian nuclear electricity
industries.
Nuclear fuel is not directly useful for nuclear weapons. Much
further processing is needed. However, for a country wishing to
develop nuclear weapons without publicly revealing the fact, an
obvious approach would seem to be combine weapons development
with a nuclear electricity generation industry.
Fortunately, solutions exist to cut greenhouse gas emissions,
reduce acid deposition, improve air quality and to solve social
problems related to recent energy use. Shifting investment from
fossil fuels like coal and oil to renewable energy and energy
efficiency would allow cleaner, more sustainable sources of energy
to take their rightful place as market leaders.
Renewable energy systems use resources that are constantly replaced
and are usually less polluting. All renewable energy sources –
solar energy, hydro power, biomass and wind energy have their
origin in activity of the sun. Geothermal energy which, because
of its inexhaustible potential, is sometimes considered as renewable
source is getting energy from the heat of the earth.
Renewable energy is a domestic resource which has the potential
to contribute to or provide complete security of energy supply.
Countries that depend on imports of fossil fuel resources are
in danger due to the risk of sharp rise of the cost of imported
energy (mainly oil). This is particularly so for developing countries,
where the oil import bill adds every year to the problem of financing
an already large external deficit.
Renewables are virtually uninterruptible and is of infinite availability
because of its wide spread of complementary technologies - thus
fitting well into a policy of diversification of energy supplies.
Renewable resources are well-recognized as a good way to protect
the economy against price fluctuations and against future environmental
costs. Technologies based on renewables are largely pollution-free
and make zero or little contribution to the greenhouse effect
with its predicted drastic climatic changes. In addition, they
produce no nuclear waste and are thus consistent with environmental
protection policies, building towards a better environment and
sustainable development.
The shape of our future will be largely determined by how we
generate and apply technological innovation the most powerful
force for progress in the modern world. The renewable energy
sources are able to have a strong transformative effect on the
whole of society in the coming decades.
By virtually all accounts, renewable energy resources will
be an increasingly important part of the power generation mix
over the next several decades. Not only do these technologies
help reduce global carbon emissions, but they also add some
much-needed flexibility to the energy resource mix by decreasing
our dependence on limited reserves of fossil fuels.
Experts agree that hydropower and biomass
will continue to dominate the renewables arena for some time.
However, the rising stars of the renewables world - wind
power and photovoltaics - are on track
to become strong players in the energy market of the next century.
Wind power is the fastest-growing electricity technology currently
available. Wind-generated electricity is already competitive
with fossil-fuel based electricity in some locations, and installed
wind power capacity now exceeds 10,000 mw world-wide. Meanwhile,
pv electricity - although currently three to four times the
cost of conventional, delivered electricity - is seeing impressive
growth world-wide. Pv is particularly attractive for applications
not served by the power grid. Advanced thin-film technology
(a much less expensive option than crystalline silicon technology)
is rapidly entering commercial-scale production.
Perhaps even more promising than the technical developments
in renewables are the resounding endorsements from major energy
companies like enron, shell, and british petroleum, which have
invested heavily in pv and wind in recent years and are planning
significant increases in these and other renewables efforts.
The energy-starved developing world, which accounts for a large
portion of the projected new electricity demand over the next
20 years, is considered one of the biggest markets for renewables.
Many of these countries are attracted to the modular nature
of renewable energy technologies, which can be located close
to the users.
The renewable technologies are far cheaper and quicker
to install than central-station power plants and their
extensive lengths of transmission line.
Renewables are also gaining favour in industrialized countries.
In the usa, national surveys show that well over half of consumers
are willing to pay more for green power, and a number of power
companies are now offering this option. In europe, strong public
support for clean energy is causing the renewables market to
expand rapidly. In 1997, the european commission released a
white paper on renewable sources of energy, in which it noted
that renewables are unevenly and insufficiently exploited in
the european union.
Contributing less than 6% to the eu’s energy consumption,
it called for a joint effort to increase this level for export
potential and to address climate change. More than half of europe’s
energy is imported, and will rise to 70% by 2020 without action.
Different scenarios show the contribution of renewables by 2010
to range from 9.9% to 12.5%, but a goal of 12% renewables share
(“an ambitious but realistic objective”) was set,
to be achieved through the installation of one million pv roofs,
15,000 mw of wind and 1,000 mw of biomass energy. The current
6% share includes large-scale hydro, which will not expand for
environmental reasons.
Growth is expected from biomass, followed by 40 gw of wind
and 100 million square metres of solar thermal collectors. Photovoltaics
will grow up 3 gwp, geothermal by 1 gwe and heat pumps by 2.5
gwth. Total capital investment to achieve the 12% target will
be 165 billion ecu (1997-2010), but it would create up to 900,000
new jobs and drop co2 emissions by 402 million tonnes/a.
The european wind energy association estimates
up to 320,000 jobs would be created if 40 gw of wind power is
installed, the pv industry association says
it would create 100,000 jobs if 3 gwp is met, the solar
industry federation estimates 250,000 jobs under its
market objective, and another 350,000 jobs could be created
to meet the export market.
The white paper proposes a number of tax incentives and other
fiscal measures to encourage investments in renewable energies,
and measures to encourage passive solar. “the overall
objective of doubling the current share of renewables to 12%
by 2010 can be realistically achieved,” it concludes,
and the contribution of renewables to electricity generation
could grow from 14% to more than 23% by 2010 if appropriate
measures are instituted.
Job creation is one of the most important features related to
the development of renewable energy sources. The employment
potential of renewables can be estimated according to the following
data :
It is important to note that when energy experts are comparing
different energy sources the question of their price is the
crucial one and renewables are mostly considered as more expensive
than fossil fuels. What is not known is the fact that such a
comparison is usually based of wrong estimation of costs. When
we pay the electric bill to the power company or fill up our
car’s tank, we usually pay a specific price for the energy
which does not express the full cost related to energy consumption.
What we do not pay are many hidden costs associated with our
energy usage. And there are several of them.
Hidden social and environmental costs and risks
associated with fossil-fuel use are principal barriers to the
commercialization of renewable technologies. It is a well recognised
fact that current markets mostly ignore these costs. In effect,
relatively harmful sources, e.g., high sulphur coal and oil,
are given an unfair market advantage over benign renewable sources.
Since competing conventional technologies are
able to pass on to society a substantial part of their costs
(such as environmental degradation and health-care expenditures)
renewable sources, which produce very few or no external and
may even cause positive external effects such as job creation,
rural regeneration and foreign-exchange earnings, are systematically
put at a disadvantage. Internalising all these costs therefore
must become a priority if a “level playing field”
is to be created.
While it is extremely difficult to quantify the external costs
of such pollution, and some simply cannot be quantified, several
studies show them to be substantial. For example, a german study
concluded that the external costs (excluding global warming)
of electricity generated from fossil-fuel plants are in the
range of 2.4-5.5 us c/kwh, while those from nuclear power plants
are 6.1-3.1 c/kwh.
According to the another study sulphur dioxide from us coal
burning plants is costing u.s. Citizens usd 82 billion per year
in additional health costs. Reduced crop yields caused by air
pollution is costing us farmers usd 7.5 billion per year. What
is important on these us figures is the fact that us citizens
are actually paying between 109 billion and 260 billion dollars
yearly in hidden energy costs. In other countries similar patterns
can also be found.
Had external economic effects been included in the market allocation
process, renewable technologies would be in a far better position
to compete with fossil fuels, and there might already have been
a substantial shift to the penetration of renewable in the market.
Energy Subsidies
many governments are heavily subsidising the energy industries.
It is interesting to note that the energy technologies with
the worst health and environmental impacts usually receive the
most government money. The worst polluters, nuclear and combustion
technologies, in the u.s. Alone receive 90% of the government
money.
The renewable energy technologies, which offer
little or no side effects, receive the least government support.
Solar technologies (both pv and thermal together) receive in
the usa only 3% of the government money. At the bottom of the
list is conservation with 2% of the subsidy dollars. And there
is not much difference in other countries of the world. This
is amazing since renewables and energy savings offer relief
from our energy problems and has no environmental side effects.
Something is really wrong here.
Military
World’s dependence on imported oil requires that military
will keep the international supply lines open. The u.s. Military
is spending between 14.6 and 54 billion dollars yearly just
defending the oil supplies coming from the persian gulf. On
the low side, the national defence council places the persian
gulf military cost at 14.6 billion. On the high side, the estimate
of 54 billion is made by the rocky mountain institute. There
are also other hidden national security costs. One of these
is military aid to oil producing nations. Another is diplomatic
and foreign policy decisions made on the basis of imported oil.
The major problem associated with nuclear power is, “what
do we do with the radioactive waste?” To date, no one has
a viable disposal solution for the thousands of tonnes of high
level radioactive waste nuclear power plants generate. This problem
is made more severe because it is a long term problem. For example,
plutonium (pu239) has a radioactive half-life of 24,400 years
and is environmentally dangerous for over several hundred thousands
years. We are making nuclear decisions now that will affect our
planet, and all life forms on it, for millennia in the future.
The world watch institute estimates the disposal costs of nuclear
waste at between 1.44 and 8.61 billion dollars per year. Radioactive
waste disposal is not actually disposal, but containment. We will
have to deal with high level waste for thousands of years. We
now have no method of actually disposing of high level waste.
We simply store it and hope our children can figure out a safe
way to deal with it. This estimate doesn’t include the cost
of nuclear accidents. What does a “chernobyl or three mile
island” cost to clean up?
LITERATURE
Energy World, James And James Sci. Publ. January 1999
EPRI Journal, July/August 1985
