ENVIRONMENTAL EFFECTS OF ENERGY USE.
By Emil Bedi, CANCEE and Hakan Falk, "Energy Saving Now".
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 deg. 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.
HOW GLOBAL WARMING WORKS
 |
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. |
THE EVIDENCE
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 deg. 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.
FUTURE IMPACTS OF CLIMATE CHANGE
The IPCC estimates that air temperatures will
increase by another 1-3,5 deg. 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 :
 |
 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.
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.
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. |
 |
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.
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. |
ACID RAIN
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:
Acid rain =
SO2 (Sulphur dioxide) + NO (Nitrogen
Oxide) + H2O (Water)
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.
DAMAGE TO TREES AND SOIL
 |
| 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. |
DESTRUCTION OF BUILDINGS
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 AND LAKES
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. |
BAD AIR QUALITY
 |
| 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.
Smog over city.
 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.
SEA POLLUTION
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| 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. |
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