The Environmental Protection Agency (EPA) lists some of the potential economic challenges caused by biofuel production. Because biofuel feedstocks include many crops that would otherwise be used for human consumption, this may lead to more land area devoted to agriculture which increases pollutants and can lead to higher food prices. Cellulosic feedstocks also compete for resources otherwise used for food production. [1]

Biofuel production can release Greenhouse Gas (GHG) emissions such as nitrous oxide released by fertilizer applications, land use pattern changes could release terrestrial carbon stocks into the atmosphere, and biorefineries use fossil fuels. Non-GHG impacts include an increase in water pollution from nutrients, pesticides, and sediment from feedstock crops like corn and soy, increases in irrigation and ethanol refining could deplete aquifers, and the impact of biofuels on tailpipe emissions could impact the air quality in some areas.[2]

Burning wood, wood pellets, and charcoal for heating and cooking may result in lower carbon dioxide emissions overall, but wood smoke contains harmful pollutants such as carbon monoxide and particulate matter. Further, if people harvest wood faster than trees grow, it can cause deforestation.[3]

Burning municipal solid waste (MSW) or wood waste to produce energy in waste-to-energy facilities keeps these materials out of landfills. However, burning garbage produces air pollution through the release of chemicals. EPA regulates strict environmental rules requiring waste-to-energy plants to implement air pollution control devices to capture air pollutants. After being burned, the remaining substance (ash) can contain high concentrations of metals from the original waste. Textile dyes, printing inks, and ceramics may contain lead and cadmium, for example. This can be partially solved by separating waste before burning.[4]

Biofuels, namely ethanol and biodiesel, are used as transportation fuels and may be considered carbon-neutral. Growing plants for biofuels is controversial because the land, fertilizers and energy to grow biofuel crops could be utilized to grow food crops instead. Large areas of natural vegetation including forests have been cut down to grow sugarcane for ethanol, and soybeans and oil palm trees for biodiesel.[5]

Ethanol and ethanol blends may burn cleaner than gasoline, but they have higher evaporative emissions, which contribute to the formation of smog. While biodiesel combustion produces fewer sulfur oxides, less particulate matter and carbon monoxide, and fewer hydrocarbons, it does create more nitrogen oxide than petroleum diesel.[6]

Updated by Erin Bennett, June 2022