In contrast, fossil fuels like oil, gas & coal are not renewable and their consumption is the leading cause of global warming. Burning fossil fuel sends carbon dioxide, the main green house gas, on a one way trip. It pumps million-year-old carbon from inside the earth into the atmosphere, where the concentration of carbon dioxide is increasing. Burning oil, gas & coal is like spending the earth’s savings, & scientists say it is changing the global climate. Wood fuel is different. As trees grow, they absorb carbon dioxide from the air in a process powered by the sun indeed, about half the weight of dry wood is this absorbed carbon. A tree destroyed in the forest fire or one that falls and decays in the forest gives up its carbon once again to the air as carbon dioxide. So continues the earth's carbon/carbon dioxide cycle.

When trees are used for energy, a part of the forest's annual growth is diverted from the natural decay and forest fire cycle into our homes to heat them. Both natural firewood and wood pellets — made by compressing waste sawdust — are energy products from the forest. Well-managed forests can be a renewable, sustainable source of energy that helps us reduce greenhouse gas emissions by displacing the use of oil, gas and coal.