World's forests
suffering from global warming

"These have suffered for several years from fragmentation and degradation caused by massive deforestation, notably to the benefit of soya and oil palm plantations."

       The world's forests have survived significant climate change in the past. But today they must face upheavals that are too rapid for their adaptation process to keep pace.

        This is the alarming observation drawn up by scientists in a special issue of the journal Science devoted to forest health and published last August. A series of six articles, signed by around twenty authors from eight countries, review the threats posed to forested lands by global change linked to human activities. Starting with global warming.

       Certainly, in the long term, forests will likely prove resilient to rapid anthropogenic climate and environmental change, either in their current form or in a new form. But in the short and medium term, the ruptures risk being radical. The alert takes on even more weight as the panorama encompasses all of the planet's sylvan areas, which cover nearly 4 billion hectares, or 30% of the land surface.

       In its latest report on the situation of the world's forests, the UN organization noted that the structured forestry sector employs 13 million people and the informal forestry sector at least 41 million. In many developing countries, particularly in Central Africa, wood is the main source of energy and 2.4 billion people, 40% of the population of the least developed countries, use it for cooking their food.

        The effects of climate change on this lush vegetation, which forms the planet's largest terrestrial carbon sink, are controversial. Some work has suggested that the rise in temperatures expected at the end of the century in this immense tropical area (from 2 to 9°C depending on the scenarios) would lead to more severe droughts.

        However, these droughts would not prevent trees from developing and storing as much or even more carbon, their growth being stimulated by the higher CO2 content of the atmosphere, therefore by more active photosynthesis.

        According to the Food and Agriculture Organization of the United Nations,  forested lands are the basis of livelihood for more than a billion people

        In its latest report on the situation of the world's forests, the UNO noted that the structured forestry sector employs 13 million people and the informal forestry sector at least 41 million. In many developing countries, particularly in Central Africa, wood is the main source of energy and 2.4 billion people, 40% of the population of the least developed countries, use it for cooking their food.

        It is also the basic material for housing 1.3 billion people, to which are added ecosystem services that are difficult to quantify but are crucial. Forests, which account for more than 80% of terrestrial biodiversity, also protect watersheds and therefore water resources. They still play a central role in climate regulation and carbon storage, with terrestrial vegetation globally absorbing a quarter of human CO2 emissions.

        Faced with these challenges, scientists advocate strengthening monitoring of the state of forest populations to identify the most vulnerable, define thresholds that could lead to rapid decline, adapt management methods and implement economic development without destruction.

        Data from satellite observations are valuable, but they still need to be refined, because they are essential to raise States' awareness of the need for a global forest policy.