Sustainability

1. A SUSTAINABLE WORLD
Author: Fabio

2. ECOLOGY
The study of the relationship between organisms and the environment in which they live is
called ecology. Ecologists identify and study ecosystems, which are systems including the
organisms of a natural community together with their environment. These organisms
depend on each other for food. Animals are consumers as they eat the food provided by
plants or other animals. Plants are called producers because they produce their own food
using sunlight. This succession of organisms linked to each other through the transfer of
energy and nutrients is called food chain. The balance within each ecosystem is maintained
by the presence of each component. The place where animals and plants live and grow is
their habitat. Every animal has a habitat, where it finds the food, water and shelter it needs
to live. If a habitat is altered, it can no longer support the species that live there. As a
consequence, many organisms are displaced or destroyed, which reduces biodiversity and
may cause species extinction. Among the causes of habitat destruction there are surface
mining, deforestation, urban development, desertification and different forms of pollution.
Finally, global warming, resulting from human emissions of greenhouse gases, is one the
main factors causing habitat loss.
Author: Giuseppe

3. WHAT IS ENERGY?
By energy we mean the ability of matter to do work or cause changes in things
because of its motions, mass or electric charge.
Energy cannot be created or destroyed. It merely changes from one form to
another. But while energy surrounds us in all aspects of life, the ability to harness
it and use it for our ends as economically as possible is the challenge we have to
face today.
Electricity, which can be produced or generated from other forms of energy, has
always been exploited by mankind and recently it has proved essential for the
development of technology.
Electricity can be generated in two ways: from a renewable energy source or from
a non-renewable one.

4. A renewable energy source is one that is replaced over a reasonable period of
time by natural processes; examples include: wind, solar energy, hydroelectricity
and geothermal energy. A non-renewable source is one that is depleted once it is
used and that will run out over time, such as coal, natural gas, oil and uranium.
Most of the world’s electricity is generated using a non-renewable energy source
such as fossil fuels and radioactive substances like uranium. But fossil-fuel power
station have harmful effects on the environment as they produce large amounts
of greenhouse gases.

5. What is alternative Energy?
Alternative energy refers to energy sources which are not
based on the burning of fossil fuels or on the splitting of the
atom. The renewed interest in this field of research derives
from the undesirable effects of pollution both from burning
fossil fuels and from nuclear waste by-products.
Examples of possible alternative energy sources which have a
less damaging impact on our environment are wind power,
solar energy, geothermal energy and hydroelectricity.

6. Windmills are a growing technology which allows people to
harness an unlimited resource that is environmentally
friendly. Solar energy is another resourceful source of energy
which does not produce any harmful by-products.
Geothermal energy is obtained by exploding the internal
heat of the Earth and can be used to generate steam to run
a steam turbine, which in turn generates electricity.

7. Finally, hydroelectricity comes from the damming of rivers and
utilizes the potential energy stored in weather.
Hydroelectricity provides twenty per cent of the world needs.
The other renewable energy sources are used to generate only a
very small portion of the world’s electricity.
The use of electricity around the world continues to increase
with the increase of population, but electricity production from
renewable energy sources is unable to meet this growing
demand. That is the reason why non-renewable energy is still
used as the main source of electricity.

8. Authors: Carlo and Matteo