The price of charcoal increases especially in large cities , such as Kinshasa .
Vast amounts of forest are deforested close to the city and the cost of transportation increases as the distance of wood sources are farther away .
The price of charcoal increases especially in large cities , such as Kinshasa , because vast amounts of forest are deforested close to the city and the cost of transportation increases as the distance of wood sources are farther away .