Today, many companies claim to offset their greenhouse gas emissions by planting trees. Last October 3rd, scientists from British and South African universities sounded the alarm by publishing a study in the journal Trends in Ecology and Evolution. They conclude that mass tree planting can be damaging, particularly in tropical regions where highly complex ecosystems are being replaced by tree monocultures that are less resistant to disease and destroy local biodiversity.
On September 21st (2023), the EU Member States agreed on legislation banning claims of neutral or positive environmental impact based solely on offsetting carbon emissions. Indeed, this often means simply planting trees, which cannot be compared with direct reduction of a company’s CO₂ emissions.
Ecological functions of forests are too frequently reduced to carbon capture. Carbon that is ultimately released into the atmosphere when the trees are felled to be used for timber or paper pulp… When tropical forests are replaced by plantations, they are dominated by just five species, sometimes overtaking native species. On a global scale, there is not enough space for all the plantation projects, and some grasslands and wetlands are inappropriately transformed into forested areas.
In response to this criticism, the Royal Botanic Gardens Kew and Botanic Gardens Conservation International have proposed ten golden rules for restoring forests. At the top of the list is the obvious: protect existing forests! Next, avoid converting grassland or wetlands, give priority to natural regeneration, and select trees that are resistant and biodiversity-friendly.