A much-used method in carbon offset world is forestation or forest carbon offset. This method includes planting new trees or protection of existing forests that should result in the creation of so-called carbon sinks that (over time) capture carbon dioxide from the atmosphere and retain it. It is undoubtedly the case that trees capture carbon dioxide but there are many questions around the sustainability and additionality of these methods. If, for example, forests are cut down for fuel, carbon is released into the air, similarly is the case with forest fires.