Total change of the climate is potentially the greatest threat both to the human species and to the atmosphere. More than 160 governments they have signed, in occasion of the encounter held to Rio De Janeiro in the year 1992, the Convention on the Climatic Changes, than it obligates them to stabilise the concentrations in atmosphere of carbon dioxide (CO2) and other harmful gases to such levels not to constitute a danger. From then, insufficient they have been the initiatives of the governments in order to stop the " climatic bomb ". If they will not be drastically reduced the gas emissions, the consequent increase of the medium temperature of our planet will modify the equilibrium of the ecosystems and will force the humanity to face enormous problems as the increase of the sea level, the emphasis of " extreme " climatic events as tides and hurricanes and one greater dissemination of diseases as malaria, asthma, encephalitis and leprosy.

The predominant use of the fossil sources of energy as the oil, the coal and the gas contributes to the release in the atmosphere of carbon dioxide and other dangerous gases. A better use of energy is urgently necessary in order to support the world-wide demand for it.

GREENPEACE asks to promote the dissemination of technologies based on uses of the renewable energetic source for excellence: the sun.

In the warm water production, for example, it can be safeguarded the atmosphere and it can be contributed, at the same time to the expense of the family. Every Italian family, daily consumes several liters of warm water. In order to heat the water generally it uses electrical boilers or boilers that they burn methane. Replacing, or integrating, these traditional systems for the warm water production with technologies (solar collectors) based on use of renewable energetic sources, the emission in atmosphere of carbon dioxide and other gases will be reduced.

In Italy, for every KWh (kilowatt-hrs) of electric power that it is produced by means of the programs of energetic saving, they can be avoided the emission in atmosphere of, approximately, 1/2 Kg of CO2. For each square meter of installed solar collector can be saved every year beyond 1,000 KWh. A family of 2-3 persons who will install 2 mq of solar collectors, will avoid the emission in atmosphere of one ton about CO2 for each year. In spite of the good level of medium exposition to sunshine in our country, is in the north-Europe that are mainly diffuse the solar systems for the warm water production.

The following examples demonstrate like, beyond safeguarding the atmosphere, the installation of solar collectors for the warm water production, will become a good investment in order to save on the expense of the family.

Example n. 1, hypothesis of a family of 2-3 persons. This family consumes every day 120-180 litres warm water, the solar collectors installed are 2 mq, saving every year on the energetic bill beyond 2,000 kWh that correspond to 320,000 Liras, the maximum cost for each mq of solar collector is Liras 1,355,000, sufficient medium time in order to cancel expenses of the system correspond to 4-5 years.

Example n. 2, hypothesis of a family of 4-5 persons. This family consumes every day 240-300 litres warm water, the solar collectors installed are 4 mq, saving every year on the energetic bill beyond 4,000 kWh that correspond to 640,000 Liras, the maximum cost for each mq of solar collector is Liras 1,355,000, sufficient medium time in order to cancel expenses of the system correspond to 4-5 years.