Emissions do not cause all their damage immediately. In the process of radiative forcing, it takes 50 years for CO2 to be at its most potent and, at minimum, another 50 years for it to be reabsorbed, which is why it is vital that climate protection actions take a much longer view than has often been the case in the past. We therefore write our planting partner contracts to cover 99 years, although our forests are designed to be around for a lot longer than that. (The Forest of Marston Vale has an 840-year lease, for example.)