Temps de lecture :6 minutes
The forest area represents a little less than 4 billion hectares, that is to say a third of the planet’s surface area. This surface area is not spread equally. Over half of these forests are just in five countries: Russia, Brazil, Canada, the United States of America and China.
Every year, 13 million hectares of forest disappear. That is just over twenty football pitches a minute. The Food and Agriculture Organization of the United Nations considers the rate to be « alarming ». (1)
But if one takes the natural extension of some forests and plantations created by man into account, the net loss is « only » 7.3 million hectares for the 2000-2005 period.
The overall rate of deforestation has slightly slowed down in the past few years, partly thanks to the efforts of environmentalists. This is also due to the increasingly larger areas of plantations, particularly in China, and to the fact that the areas that are easier or more profitable to cut have already been used. The fact remains that between 1990 and 2005, almost 3 % of total forest cover was lost.
There are many reasons for deforestation. Most of them are linked to Man. It is mostly to do with wood for heating, the extension of agricultural areas and urban areas, crops for biofuel, wood demand for building or precious essences. Even so-called natural causes are often linked to human activity : over 80 % of fires could in fact be caused by Man and some illnesses or invasions of insect pests are linked to the environment being changed by Man.
There are many different types of forest. Tropical forests, temperate forests, boreal forests or mangroves, each forest has its own particularities. Primary forests – that have not been changed by Man – are the opposite of secondary forests – that have been, and of plantations, which are even more artificial. The first represent 36% of the forest area and are those which are decreasing fastest : they lose 6 million ha a year. The surface area is regularly increasing but it still only represents 3.8% of the overall area.
Deforestation particularly affects certain countries like Brazil whilst the forest area in other countries, like France, increases because of the rural exodus. [Debate]
A definition problem
It is difficult to assess the extent of the problem because the terms are ambiguous. When do several trees make a forest? What is a tree and what is a shrub ? There are in fact no obvious answers for these seemingly simple questions. And yet, any estimate of the world’s forest surface area depends on this.  Depending on the definitions, the total forest surface area can almost triple : from 2393 billion to 6050 billion hectares. Today, the FAO definition is used as an international reference, but it is criticised by associations for putting artificial forests and primary forests and healthy forests and seriously damaged forests on the same level. This means that the real crisis is underestimated. (3) [indicator]
Forests are very useful to humanity in many ways but their importance is often underestimated. They of course produce some of the oxygen that can be found in air but they also contribute to air quality by filtering dust and pollutants. They provide a habitat for 50% to 80% of the planet’s animal and vegetation species and are a major reservoir of biodiversity. [Debate]
It stabilises soil and protects it from erosion or disasters. Coastal areas protected by mangroves were thus much less affected by the 2004 tsunami. (4)
Forest soil can store large amounts of water and thus plays a regulatory part in the water system and flood prevention. It purifies rain water: the city of New York thus obtains all of its drinking water from water naturally filtered by neighbouring forests. (5)
Forests also play a macro and micro climatic role, by reducing thermal variations and adding humidity to air.
Forests and populations
According to FAO estimates, about 500 million people live in forests and their surrounding areas, and in some cases, the forests are their main source of food. Almost everywhere, forests regularly complement food from agriculture. For certain local populations, deforestation means their way of life being destroyed and destitution.
The forest industry employed almost 10 million people in 2005 and in 2007 it generated 327 billion dollars. Wood is an important part of the GDP of about 10 tropical and Nordic countries.
Forests and global warming
Forests play a very important but paradoxical part in global warming. As it grows, the vegetation turns CO2 in the atmosphere into organic matter. Forests thus stock about 280 billion tons of carbon in their biomass. If you add this to the carbon stocked in soil, it is more than can be found in the atmosphere!
If these forests are brutally destroyed, deforestation releases some of this carbon. This phenomenon is currently responsible for almost 20% of the world’s greenhouse gas emissions. However, once they have matured, forests are carbon neutral. If one chops a little wood, it grows back and the CO2 that is released is therefore reabsorbed. In a forest that is well managed, using wood for heating or to produce energy is therefore not only renewable, but also carbon neutral. It is therefore also very eco-friendly. This is why a return to wood energy is now encouraged in European forests. (6)
It should be noted that some details about how forests function are still not very well understood. They can in fact, in certain conditions, release CO2 rather than stock it. Trees can also release small amounts of greenhouse gases like methane. [Debate]
Consequences of global warming
Increasing temperatures changes the way in which essences are spread : like other species, trees migrate towards the North or towards higher altitudes. Global warming can also favour the proliferation of insect pests. This is the case, for example, of the western part of Canada which is battling an insect called the mountain pine beetle. It is believed to be responsible for the death of millions of trees. (7)
Moreover, the increase of CO2 levels in the atmosphere favours certain essences to the detriment of others. And heat waves – like those in the summer of 2003 in Europe considerably slows down the growth of vegetation.
The Kyoto Protocol
The importance of forests in relation to global warming made them a subject of debate in the Kyoto Protocol negotiations. Forests are seen as « carbon wells » and planting trees can be considered a way of fighting global warming. Now, an important point is also being discussed for the future of the protocol from 2012 : avoided deforestation, known as REDD (Reduced Emissions from Deforestation and Degradation in developing countries). The idea is to financially encourage the protection of existing forests. This is not currently the case. However, a system like this would be extremely hard to set up on an international level. (8)
A daily basis
If in the West, forests are places that make one think of calm and serenity, this is not the case everywhere. Militants who oppose deforestation often have to face extreme violence from armed groups. These groups often act deep in forests where no-one can see them.
Many people who defend the environment have thus been assassinated for challenging woodcutters. The most famous is Chico Mendes, a Brazilian union activist who started the movement against deforestation in his country. He was assassinated in his home in 1988. But every year, militants pay for their commitment with their lives. This does not only happen in developing countries: in 2006, two forest wardens were assassinated in Guyana by gold washers.
Indonesia’s, Malaysia’s and Papua New Guinea’s tropical forests are spread over a multitude of islands and are home to particularly rich and interesting biodiversity. In 2006, the deforestation rate of the Indonesian tropical forest reached a new record: 2.6 million hectares instead of 1.8 million a year between 2000 and 2005 (FAO). This is mainly due to oil palm crops for fuel (Europe is the largest importer) and for food. According to Friends of the Earth, at this rate, 98% of the forest will disappear in 20 years time and so will endemic wildlife and vegetation including its most famous representative, the orang-utan.