Now that we have examined the potential for agriculture to supply some of our requirements for the future, we will turn our attention to forestry. It is well established that deforestation and land-use change play a significant role in contributing to increased levels of atmospheric carbon dioxide. However, biological systems also have the capacity to reverse or ameliorate this trend, because the atmospheric carbon can be sequestered in sinks, such as expanding forests. The process of tree growth utilizes atmospheric carbon in the production of wood biomass and this sequestered carbon can continue to be held in products that are derived from trees. The growing of trees is good, but so is harvesting them, provided it is done sustainably.