Firewood and charcoal have been used for thousands of years to provide heat and light to humans. Both are popular today, although in more prosperous parts of the world this choice is based more on aesthetics than on need. Although firewood and charcoal are both renewable sources of energy, demand for both can outpace forests’ ability to regenerate on a local or national basis. Although good forestry practices can ensure better local supplies, overharvesting can lead in extreme cases to desertification. Both firewood and charcoal have environmental consequences as a result of being burned, and green alternatives have been developed that have a less adverse affect on the ecosystem.