http://uk.oneworld.net/article/archive/8379 en_GB_uk http://uk.oneworld.net/article/view/124192/1/8379 This is a contraversial area, both because of the underlying science and because of practical issues of whether there is enough land, whether new trees are actually being planted and whether they are being maintained. How does it work?: forests take up CO2 from the atmosphere and store it as biomass. Some carbon may be locked-up for the long-term in roots and soils and some is released when trees are harvested. Forestry offsets are normally based on estimates of the long-term carbon storage,