An uncontrolled forest fire can destroy everything in its pathway, spreading for miles, crossing rivers and roads. Each year, between 60,000 and 80,000 forest fires happen, destroying between 3 and 10 million hectares. While forest fires have different consequences on the environment, depending on their size and frequency, the causes are also diverse.

Causes increasingly linked to human activities

Until a few hundred years ago, forest fires were a natural "activity" that resulted mainly from rare phenomena, for example, a volcanic eruption or an earthquake, which occur in particular geographic areas. It is, thus, not them but lightning that is the main cause of the outbreaks of naturally occurring forest fires. For example, it represents about 2% of fires in the Mediterranean area and nearly 30% in Quebec! In Spain, 5% of fires are due to natural causes, especially in dry and hot places. In some regions of the country (Aragon, Pyrenean ranges, etc.), thunderstorms and lightning are responsible for 25% of forest fire outbreaks in the absence of rain. Other exceptional circumstances and very unusual phenomena, such as the collision of two siliceous rocks producing a spark, can also with (minimal) impact on fires. Fires of natural origin are often quite quickly channeled since they usually have only one source.

However, today, these natural causes are much less frequent and are now giving way to human activities, whether voluntary or not:

43% of forest fires caused by humans are linked to carelessness (cigarette butts, garbage dumps, burning). They can also happen as a result of power surges, damage to power lines, or even military accidents, as was the case in 2016 and 2017 at the Captieux military camp in Gironde (caused by military test firing, destroying 1300 hectares of pine trees) or at the Le Mans military camp in April 2017. Finally, carelessness is often linked to leisure activities, agricultural or forestry work (55% of fires)

25% of man-made forest fires are caused by arsonists, revenge, or political or administrative strategy.

The remainder being classified of unknown origin. This is how, since 1973, more than 1.1 million hectares have been burned in France.

Consequences of forest fires

Flora and fauna directly impacted

The impact of a forest fire on flora and fauna is linked to its intensity and to the biological interest of the species concerned.

A fire has immediate consequences (modification of the landscape, the disappearance of animals or plants, sometimes belonging to rare species), and in the longer term, if we consider the time necessary for the reconstitution of biotopes. Reptiles and crawling animals are the most affected among the fauna, as they cannot escape the flames like birds and game.

The consequences on soils are determined by the amount of moisture they contain and the presence of organic matter. They can be affected by a loss of mineral elements like nitrogen, but the main problem is the degradation of the vegetation cover. It can be the source of increased runoff, resulting in a significant risk of erosion.

Finally, the landscapes undergo significant modifications, either by the absence of vegetation or by the presence of numerous charred trees. Reforestation makes it possible to heal a landscape by reconstituting green masses, but the original atmospheres of the forests are very difficult to restore.

Reforestation operations can be considered with a view to sustainable management. They are not systematic but make it possible to reconstitute the landscapes while reducing the visual impact or avoiding soil erosion. For reforestation, stands that are less combustible by their structure and composition are preferred.

Other consequences

1. The destruction of vast quantities of heavy wood of high value, whose lifespan sometimes reaches hundreds of years, which causes direct material losses to the countries that contain those forests, as forest wood is an important part of the raw materials for many industries such as furniture and construction industry.

2. Causing the acceleration of desertification’s advance towards green areas, as forests constitute excellent barriers to protect green areas from the encroachment of sand dunes coming from dry areas. They also work to preserve and fertilize the soil and prevent the deterioration of its structure, thus protecting it from desertification.

3. Destruction of residential areas adjacent to forests, displacing thousands of people and causing loss of life, which may be significant in some fires.

4. Forest fires cause the production of huge amounts of carbon dioxide and other no less harmful amounts of dust particles that reach areas hundreds of miles away from the area of ​​​​the fire and can cause health and environmental problems. Due to the quantities of carbon dioxide that they emit, forest fires. It is one of the factors that contribute to the exacerbation of global warming.

The most famous fires in the world

It is impossible to enumerate all the huge fires that occurred in the world during the past thirty years only, but some fires that have been imprinted in the world's memory as the worst fires in terms of the forest areas or the number of human victims.

Among the most famous of these fires, which can be classified according to the country in which they occurred, are:

. The Indonesian forest fires, a group of consecutive fires that started in 1999 and ended in 2005 and spread over large areas in Kalmatana, Sumatra, Java, and others, which led to the destruction of hundreds of thousands of kilometers of Indonesian forests in these areas, and what made the situation worse was that it came after the Kalmatana fire Which erupted in 1998 and caused the destruction of more than 95 thousand square kilometers. Indonesia is one of the countries in the world that deliberately ignite forest fires to make room for the cultivation of palm trees for the production of oils and provide additional spaces for the establishment of new residential areas to meet the requirements of the population increase. Therefore we find that the huge fires are one of the most prominent environmental disasters that Indonesia has been famous for since the beginning of the twentieth century.

. Recurrent Australian forest fires, the most famous of which were the repeated Sydney fires in 1983, 1995, 1997, and 2000, as well as the South Australian state fire, which occurred in the summer of 2014 and destroyed more than 240 square kilometers of forests. Fires are an annual event that recurs in several parts of Australia, and some climate experts attribute these fires to the worsening of global warming.