Climate change caused by greenhouse gas emissions is a reality. Currently, our ever-growing need for energy is mainly fulfilled by fossil fuels. The carbon emissions from fossil fuels are the cause of this upset in the balance of the carbon cycle and affect the equilibrium between plants, animals, and natural events, such as a forest fire. Simply put, plants consume the carbon dioxide (CO2) and release oxygen (O2) while animals and forest fires consume O2 and release CO2. Hydrocarbons buried for millions of years are combusted to release energy, but we are left with great quantities of CO2 that are returned to the atmosphere.
One way to reestablish the equilibrium is to use renewable fuels. Renewable fuels are fuels produced from renewable resources. Examples include biofuels made from biomass and hydrogen produced with electricity made from hydro, tidal, wind, or solar energy. Renewable fuels produced from biomass generally start as plant material. As depicted by the carbon cycle principal (see Figure 1), growing plants absorb CO2 from the air and convert it into hydrocarbon through the process of photosynthesis. Energy, which is provided by the sun, is required to break up the CO2 molecule and rearrange it with other elements to produce the new plant material. The photosynthesis process also produces oxygen that is returned to the atmosphere. When biomass is used to produce energy, the hydrocarbons are transformed back into CO2, which releases energy that can be used in different ways. For example, an area of land produces wood that is used as fuel to heat a building. The CO2 from wood combustion is then used to grow the trees in this same area, thus closing the loop.