The big turning point came in 2018 when I signed a legally binding commitment to ensure that Ecosia could never be sold and that 100% of our profits would always go to the planet. Today, your searches enable us to work with partners to plant and protect 1,250 species of trees across 95,000 locations globally.
Keywords plant and protect. Basically a papermill can plant trees to harvest 20 years later and in the meantime sell carbon offsets for 19 years then harvest and replant.
Can't say for sure they're doing it, but from what I hear just about every tree is eligible for a "carbon offset" and some companies abuse it by saying "this is our tree" as long as it's not cut down within x months and use it as a carbon offset or a "protected tree."