As well as buying carbon credits, we plants trees on behalf of our members. Why? Because trees are amazing and incredibly effective at sequestering carbon dioxide! But because every tree is different, it's difficult to accurately predict how much CO2 they remove each year and therefore we can't guarantee how much carbon they offset. So really your forest is a bonus offset - roughly 1 tCO2 is sequestered each year for every 4 mangroves.