Sustainability

Deforestation

Deforestation seriously threatens the survival of forests because as well as felling trees it also involves building roads and people migrating to the deforested areas. The proportions of this environmental disaster are really impressive, especially in Africa. Over the last thirty years, Africa has lost two thirds of its tropical forests and its ancient forests now cover just 8% of the original surface. 85% of the forests has gone lost in the Congo basin, and the remaining 15% is now threatened by the timber industry.  
The main causes of deforestation are:
• replacement of forest areas with crops and farms: after taking the most valuable trees for the timber trade, the forest is burnt down, thus killing animals and plants. In September 1991, the most disastrous year ever recorded in the Amazonian forest, over 50,000 fires were recorded both by air and by satellite
• timber: ancient trees are felled to make timber or cellulose for furniture or paper industries. Whatever system is used to fell the trees, it seriously damages the ecosystem and is aggravated by the construction of roads for the access of vehicles and for the transport of the logs. In this way, many trees of poor economic value are felled as well, which have however a remarkable biological and ecological value
• firewood: this activity is mainly carried out by the indigenous people who, due to the recent population increase, have to look for energy sources for their sustenance. This phenomenon aggravates therefore the more massive industrial problem
• constructions of roads (for the above activities), dams and industrial exploitation of mines also involve massive deforestation.  
Consequences of deforestation
Since the forest is vital for the rain cycle, deforestation involves climatic imbalances at a local level and because of the proportions of this phenomenon also on a global scale, since it affects the composition of the atmosphere and consequently the greenhouse effect. They are the greatest natural purifiers of the earth: to fell forests means to get rid of a "pool" of carbon dioxide, leaving more of this gas in the air, which could affect the heating of the Earth.