deforestation: causes, consequences and solutions
Deforestation is a phenomenon that occurs when a forested area is destroyed or reduced in size due to human or natural actions. It can have serious consequences on the environment, biodiversity, and climate. According to the Food and Agriculture Organization (FAO) of the United Nations, 420 million hectares of forest have been lost worldwide since 1990 due to deforestation. What are the causes of this scourge? What are its impacts on the planet? And what are the solutions to preserve the world's forests?
Causes of deforestation
Among the natural factors, we find:
Forest fires, which can be triggered by lightning, drought, or climate change. For example, the bushfires that ravaged Australia from June 2019 to May 2020 destroyed over 18 million hectares of forest and emitted more than 700 million tons of CO2 into the atmosphere.
Tree diseases, such as Dutch elm disease decimating plane trees in Europe or the mountain pine beetle attacking conifers in North America.
Parasites, like processionary caterpillars affecting pine or oak trees, defoliating them and weakening them.
However, it is primarily human activities that are responsible for deforestation on a global scale. According to the State of the World's Forests report published by the FAO in 2016, nearly 80% of global deforestation is caused by agriculture, with the remaining 20% divided among industrialization, infrastructure construction (roads, dams) primarily, followed by mining activities, and finally, urbanization. In detail, here are some major causes of deforestation:
Agriculture, representing 80% of deforestation. It can be either commercial agriculture or subsistence farming (local peasant agriculture, especially in developing countries). Subsistence farming accounts for 30 to 35% of global deforestation, while commercial or industrial agriculture (large-scale cultivation and livestock farming) accounts for 45 to 50%. Livestock is the cause of about 14% of global deforestation. Among the crops most involved in deforestation are soy, palm oil, cocoa, coffee, or cotton.
Infrastructure construction accounts for about 8% of deforestation. This includes roads, hydroelectric dams, pipelines, or power lines that fragment forests and make them accessible to forestry or agricultural operators.
Mining activities are responsible for about 6% of forest loss. This mainly involves the extraction of minerals such as gold, copper, iron, or coal, which often requires clearing wooded areas to dig open-pit or underground mines.
Urbanization contributes around 5%. This involves the development of cities and peri-urban areas encroaching on natural spaces and leading to significant wood consumption for construction or heating.
Contrary to what is often heard, forestry industries are not among the main culprits of deforestation. The explanation is simple: forestry industry companies typically operate on cultivated forest areas, i.e., forests that are regularly replanted for sustainable exploitation.
The consequences of deforestation
Deforestation has numerous consequences on natural ecosystems and poses serious resilience problems.
Consequences of deforestation on biodiversity
The most well-known consequence of deforestation is the threat to biodiversity. Indeed, forests are rich habitats with a diverse array of animal and plant species, with some forests being true biodiversity reservoirs, among the most diversified in the world. For instance, the Amazon rainforest houses more than 10% of Earth's known living species. The disappearance of forests results in the loss of habitats for these species, putting them at risk of extinction or forcing them to migrate to less suitable areas. According to a study published in the journal Science in 2019, deforestation led to the disappearance of 17% of bird, mammal, and amphibian populations in tropical areas between 1970 and 2010.
Consequences of deforestation on climate
Deforestation also has a significant impact on the climate, both locally and globally. Locally, the removal of forests alters the hydrological cycle, the movement of water between soil, plants, the atmosphere, and water bodies. Trees play a crucial role in evapotranspiration, which involves the evaporation of water from the soil and the transpiration of leaves. This process helps cool the ambient air and form clouds that bring precipitation. Without trees, the soil dries up, the air heats up, and rainfall becomes scarce. This can lead to phenomena such as drought, erosion, or desertification.
At the global level, deforestation contributes to climate change by increasing greenhouse gas (GHG) emissions. Trees act as carbon sinks, absorbing CO2 from the atmosphere and storing it in their biomass (trunk, branches, leaves, roots). When trees are cut down or burned, they release the CO2 they accumulated during their growth. According to the Intergovernmental Panel on Climate Change (IPCC), deforestation accounts for approximately 10% of global GHG emissions.
Solutions to combat deforestation
Faced with this alarming situation, it is urgent to take action to preserve the world's forests and their ecosystem services. Several solutions exist at different levels:
International level: There are conventions and agreements aimed at protecting forests and reducing emissions related to deforestation. For example, the Convention on Biological Diversity (CBD) adopted a Strategic Plan for Biodiversity 2011-2020 in 2010, which includes an objective to halve the rate of loss of natural habitats, including forests. The Paris Agreement on climate, signed in 2015, also recognizes the role of forests in mitigating climate change and encourages countries to implement actions to reduce emissions related to deforestation and forest degradation (REDD+).
National level: Policies and laws exist to regulate forest exploitation and promote sustainable forest management. It involves reconciling economic, social, and environmental needs related to forests while respecting principles of precaution, equity, and participation. For example, in 2012, Brazil adopted a new Forest Code that requires landowners to maintain a legal reserve of forest on their lands, ranging from 20% to 80% depending on the regions. France also adopted a Forest Orientation Law in 2001 aiming to ensure the multifunctionality of forests (production, protection, public access) and promote their sustainable management.
Local level: Initiatives and projects aim to involve local populations in forest conservation and restoration. This includes recognizing land rights and traditional knowledge of forest communities, involving them in decisions regarding the use of forest resources, providing them with sustainable economic alternatives, and raising awareness about environmental issues. For example, the Forest Garden project by the NGO Trees for the Future helps farmers in sub-Saharan Africa plant fruit trees, vegetables, and staple crops on their plots to reduce pressure on surrounding forests and improve food security.
Individual level: There are actions and choices that everyone can make to reduce their ecological footprint related to deforestation. This includes consuming fewer products derived from deforestation, such as meat, soy, palm oil, or cocoa, or opting for certified products from organic or fair trade agriculture. It also involves reducing paper and wood consumption, choosing recycled paper or wood certified by FSC (Forest Stewardship Council) or PEFC (Programme for the Endorsement of Forest Certification), ensuring sustainable forest management. Lastly, supporting the actions of associations or organizations working for forest protection, such as Greenpeace, WWF, or Rainforest Alliance.
Deforestation is a major problem threatening biodiversity, climate, and the well-being of populations. It is essential to act at all levels to preserve the world's forests and their ecosystem services. Deforestation is not inevitable; there are solutions to reconcile human development and nature conservation. All that is needed is political will, international cooperation, and individual responsibility to implement them.