Transcript Diapositiva 1

S.O.S Earth
CAUSES
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Carbon dioxide
Deforestation
Biocide
Population growth
Increase energy demand
CONSEQUECES
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Thinning of the Ozone layer
Greenhause effect
Acid rain
Growth level of the sea
Extinct animals
CARBON DIOXIDE
It is a chemical compound composed of two oxygen atoms covalently
bonded to a single carbon atom. It is a gas at standard temperature and
pressure and exists in Earth's atmosphere in this state.
Within the atmosphere it is currently at a globally averaged concentration
of approximately 387 ppm by volume. Atmospheric concentrations of
carbon dioxide fluctuate slightly with the change of the seasons,
driven primarily by seasonal plant growth in the Northern Hemisphere.
Concentrations of carbon dioxide fall during the northern spring
and summer as plants consume the gas, and rise during the northern
autumn and winter as plants go dormant, die and decay.
Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and
nearnfrared.
Carbon Dioxide from Power Plants
In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of
electricity generation
Carbon Dioxide Emitted from Cars
About 33% of U.S carbon dioxide emissions comes from the burning of gasoline in internal-combustion
engines of cars and light trucks
Carbon Dioxide from Airplanes
The UN's Intergovernmental Panel on Climate Change estimates that aviation causes 3.5 percent of global
warming, and that the figure could rise to 15 percent by 2050.
Carbon Dioxide from Buildings
Buildings structure account for about 12% of carbon dioxide emissions.
DEFORESTATION
After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbn
dioxide. Deforestation is responsible for 20-25% of all carbon emissions entering the atmosphere, by the
burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests
each year, the equivalent in area to the size of Italy. The destroying of tropical forests alone is throwing
hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate
forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually.
In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.
Deforestation results in decline in biodiversity. The removal or destruction of areas of forest cover has
resulted in a degraded environment with reduced biodiversity. Forests support biodiversity, providing habitat
for wildlife; moreover, forests foster medicinal conservation. With forest biotopes being irreplaceable source
of new drugs (such as taxol), deforestation can destroy genetic variations (such as crop resistance)
irretrievably.
Since the tropical rainforests are the most diverse ecosystems on earth and about 80% of the world's known
biodiversity could be found in tropical rainforests removal or destruction of significant areas of forest cover
has resulted in a degraded environment with reduced biodiversity.
Deforestation is a contributor to global warming, and is often cited as one of the major causes of the
enhanced greenhouse effect. Tropical deforestation is responsible for approximately 20% of world greenhouse
gas emissions.
BIOCIDES
A biocide is a chemical substance capable of killing living organisms, usually in a selective way. Biocides are
commonly used in medicine, agriculture, forestry, and in industry where they prevent the fouling of water
and oil pipelines. Some substances used as biocides are also employed as anti-fouling agents or
disinfectants under other circumstances: chlorine, for example, is used as a short-life biocide in industrial
water treatment but as a disinfectant in swimming pools. Many biocides are synthetic, but a class of
natural biocides, derived from e.g. bacteria and plants, includes brassica oleracea, brassica oleracea
gemmifera, and clostridium botulinum bacteria.A biocide can be:
• A pesticide
• An antimicrobial
Biocides can be added to other materials (typically liquids) to protect them against biological infestation and
growth. For example, certain types of quaternary ammonium compounds (quats) are added to pool water
or industrial water systems to act as an algicide, protecting the water from infestation and growth of
algae. Chlorine is also added during wastewater treatment to kill micro-organisms, algae, and so on. It is
often impractical to store and use poisonous chlorine gas for water treatment, so alternative methods of
adding chlorine are used.
Since biocides are intended to kill living organisms, many biocidal products pose significant risk to human
health and welfare. Great care is required when handling biocides and appropriate protective clothing and
equipment should be used. The use of biocides can also have significant adverse effects on the natural
environment. Anti-fouling paints, especially those utilising organic tin compounds such as TBT, have been
shown to have severe and long-lasting impacts on marine eco-systems and such materials are now
banned in many countries for commercial and recreational vessels (though sometimes still used for naval
vessels).
Disposal of used or unwanted biocides must be undertaken carefully to avoid serious and potentially longlasting damage to the environment.
POPULATION GROWTH
The increase in the number of the population leads to a degradation of quality. Air, tillable soil, water, mineral
resources are fixed or only partially substitutable. There is therefore a clear correlation between
population growth and environmental deterioration.
The environmental impact of consumption of raw materials is much stronger for the inhabitants of developed
countries. The ratio is 20:1 for the consumption of aluminum, copper for 17:1, 10:1 for iron, 9:1 for fossil
fuels, 3:1 for the timber. During the first 6 years of life a baby American consumes 700 tonnes of ore, the
equivalent of 4,000 barrels of oil into energy, 25 tons of food plants and 28 tons of animal products. Also
produces an average of 1,000 tons of waste air, 10,000 tonnes of liquid waste and 1,000 tons of solid
waste.
INCREASE ENERGY DEMAND
Daily life requires more and more the availability of energy. For its production and processing processes are
sometimes dangerous for the environment and highly polluting.
A substance that has the most severe impacts on the environment is carbon dioxide (CO2) that comes
from combustion processes. With the help of carbon dioxide into the activities of industries, power plants
(excluding hydroelectric ) and the exhaust of motor vehicles. The accumulation of CO2 in the atmosphere
is particularly bad because this gas helps to increase the greenhouse effect.
With regard to emissions of vehicles already opens up the solution of the hydrogen engine that, through
special devices, enter into the atmosphere as an exhaust only water vapor. A further reduction of
pollutant emissions will find wide spread when the engine with compressed air, which already appeared
on the market.
To reduce emissions of carbon dioxide is also necessary to reduce the production of power. A reduction in
consumption of energy is the primary objective to be achieved to get a result in this direction.
A reduction in consumption of electricity also affects domestic dwellings. The goal is to reduce wastage,
especially when caused by negligence or misuse of electrical appliances at home. The refrigerator,
washing machine, freezer, TV devices are more widely used and for this reason special care should be
taken in their use and maintenance to reduce wastage. Not free speech is that domestic lighting: new
types of lamps allow substantial savings in power consumption. The containment of power consumption
due to heating can help reduce the impact on the environment.
Particularly worrisome in this regard is the increase of energy consumption due to the spread of the
conditioning that leads home, in the hot season, a peak in demand for electricity
Even the refrigeration contribute, through the consumption of electricity, the increase of carbon dioxide
in the atmosphere. All the refrigeration industry is intent to address the problem and to seek new
solutions that reduce the environmental impact . For some years now being discussed at international
level on how to reduce the effects of the operation of refrigeration systems on the environment, in
particular the ozone hole and the greenhouse effect.
J = joule (1 chilowattora (kwh) equivale esattamente a 3 600 000 J)
1 TJ ( TeraJoule) = 1012 J 100 TJ = 27800000 kwh
OZONE DEPLETION
The Earth's stratosphere contains a relatively high concentration of ozone, a gas consisting of three oxygen
atoms (O3) and that is a real screen against dangerous ultraviolet radiation (UV rays) coming from the
sun. Every year during the spring in the Southern Hemisphere, the concentration of ozone in the
stratospheric situated near the South Pole down owing to natural variations. Unfortunately, because of
the pollutants released into the atmosphere, since the mid-seventies this periodic decline has become
increasingly large, leading to much talk about the phenomenon as the "ozone hole". Has recently
identified a thinning of the ozone layer in a small area to the North Pole, above the Arctic Sea, which could
lead to the formation of another hole on the opposite side. In fact, the phenomenon is not nothing but
the most obvious aspect of the general and gradual decrease of ozone in the stratosphere.
The problem is extremely important as a reduction of the ozone shield in an increase in UV rays that reach the
surface of the Earth. In the over-exposure to these rays is related to an increased risk of skin cancer, which
is generated as a result of induced mutations in the DNA of epithelial cells. Ultraviolet rays can also cause
a partial inhibition of photosynthesis of plants, causing a slowdown in growth and, in the case of
cultivated plants, a reduction of crops. UV rays can also reduce the photosynthetic activity of
phytoplankton which is located at the base of the marine food chain, causing a mismatch accordingly
considerably dependent ocean ecosystems.
GREENHOUSE EFFECT
The greenhouse effect is a phenomenon without which life as we know it now would not be possible. This
process consists of a warming effect of the so-called greenhouse gases, compounds present in air at relatively
low concentrations (carbon dioxide, water vapor, methane, etc.).
Greenhouse gases allow sunlight to pass through the atmosphere and impede the transition to the area of the
infrared radiation coming from the surface of the Earth and lower atmosphere (the heat reissued), in practice
they behave like the glass of a greenhouse and promote the adjustment and maintenance of Earth's
temperature to values today.
This process has always occurred naturally and causes the temperature of the Earth is about 33 ° C warmer
than it would without the presence of these gases.
Now, however, it is believed that the climate of the Earth is about to change because human activities are
altering the chemical composition of the atmosphere. The huge emissions of anthropogenic greenhouse gases
are causing an increase in the Earth's temperature by determining, as a result of changes in climate and load
global and local. Before the Industrial Revolution, man released very few gases into the atmosphere, but now
the growth of the population, the use of fossil fuels and deforestation greatly contribute to the change in
atmospheric composition.
ACID RAIN
Acid rain is rainfall contaminated by the presence of acid
compounds, which were formed in the atmosphere as a
result of combustion processes. They are among the
main causes of the destruction of vegetation. Thermal
power plants and heating plants discharged into the
atmosphere millions of tons of sulfur dioxide and oxides
of nitrogen. These substances, reacting with water vapor
in the atmosphere in the form of clouds, some are acidic,
especially sulfuric acid and nitric acid (or nitrous).
The fallout with rain of such compounds in nature-acid
chemistry can also occur at a considerable distance from
the places where they are occurring combustion processes,
and impacts heavily on the whole environment.
Acidic substances contained in rainwater damage water courses.
The pH of a lake, which is normally equal to 8, with acid rain and the melting snows of spring it changes, giving
off a number of serious consequences for aquatic life. In fact, below the 5.5 pH dies most fish, crustaceans and
molluscs. To be affected are the materials of the monuments and buildings: the marble (calcium carbonate,
anhydrous), for example, is transformed into gypsum (calcium sulfate dihydrate) and then crumble, so the
plaster and cement, and metals are corroded.
GROWTH LEVEL OF THE SEA
Over the next one hundred years is expected to increase in the mean sea level of between 9 and 88 cm, due to
atmospheric emissions of greenhouse gases. This will increase both from the gradual melting of glaciers,
both by the natural expansion of the oceans due to the fact that water increases in volume when the
temperature increases.
Even a few inches of elevation would cause chaos: flooding in coastal areas, contamination of potable
groundwater, increase in salinity of estuaries are just some of the parts of this alarming scenario. Many of
the cities on the coast would have problems. Strategic resources for coastal communities such as beaches,
drinking water, fisheries, coral reefs and atolls are at risk.
EXTINCT ANIMALS
The increase of pollution in our planet can have disastrous effects not only for the climate and oceans, but also
for the inhabitants of the Earth. The flora and fauna are negatively affected by these changes, because
climate change also means changes in the lives of animals and then a major effort to adapt.
 The Vertebrates
In all, the 3524 vertebrate species are threatened analyzed on 17,127 (21%). Compared to total
known species, namely 56,586, the percentage of those at risk is 6%.
 Invertebrates
Among the invertebrates, are endangered species on the 1959 assessed 3382 (but are more than one
million one hundred ninety thousand, and those known). The percentage of threatened species than
those tested is 58% while compared to those known to be 0.2%.
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Plants
Among the plants are endangered species on the 6774 assessed 9706 (the species are known beyond
28,700). The percentage of threatened species than is analyzed by 69% when compared to those known
to be 2%.
THERE IS STILL TIME TO ACT
It is expected that world population will grow 80 - 85 million people every year for at least the next 30 years.
At the same time, more and more nations, and then billions more people, reach higher levels of economic
development, production and consumption. This will, in turn, a significant increase in the use of natural
resources and energy.
Of course, all nations and their inhabitants have the right to improve their standard of living, but if current
trends continue, the damage to the environment certainly will increase and accelerate. The good news is
that we can protect our world and our security. But to do this we need to stabilize the population,
develop renewable energy systems and environmentally friendly technologies and adopt sustainable and
productive practices. These goals will not be 'difficult from a technical viewpoint it' s very expensive: we
could do all this with much less effort and money than the world currently spends on weapons and wars
and creating in the process, a strong economy and sustainable.
But, in order to achieve this goal, we need to define and share the vision of a future positive, safe and healthy,
but above all we must work together to create it.