What is a Carbon Neutral Fuel?

Introduction:

At the 2020 Pennsylvania Farm Show the Hardwoods Development Council (HDC) hosted the Pennsylvania Hardwoods exhibit. The exhibit’s theme was Imagine the Opportunities of a Smaller Carbon Footprint. The exhibit was made possible by a collaboration between the HDC and the three Pennsylvania Hardwood Utilization Groups (HUGs): Allegheny Hardwood Utilization Group, Keystone Wood Products Association, and the Northern Tier Hardwood Association.

The Hardwoods exhibit featured seven educational displays, all pertaining to how implementing sustainable forestry practices and the use of hardwood products can help reduce one’s carbon footprint. This is the third in a series of seven articles. These articles will provide information pertaining to each of the seven themes that were displayed. One article will be provided monthly.

Article 3: What is a Carbon Neutral Fuel?

By Jonathan Geyer and Dave Jackson

A carbon neutral fuel is one that does not increase the amount of carbon dioxide (CO2) cycling through the atmosphere. For example, burning wood is considered carbon neutral. When burned, it does not increase the amount of CO2 in the atmosphere. This is because the forest carbon cycle is a closed loop system (Figure 1). As trees grow, they photosynthesize, taking in carbon dioxide, converting the carbon into woody biomass and releasing the oxygen. Removing carbon from the atmosphere and storing it is known as carbon sequestration. The carbon stored in wood is released back into the atmosphere when the wood is combusted. However, new carbon is sequestered by other trees as they grow, and the cycle continues.

Figure 1: When wood is combusted, carbon is released as carbon dioxide. It is then sequestered again by other trees as they grow.

Wood-based fuel like firewood and wood pellets release a minimal amount of carbon into the atmosphere compared to coal, oil, and natural gas. When fossil fuels are combusted enormous volumes of CO2 are released into the atmosphere, more than what trees can sequester. Fossil fuel combustion leads to large increases in the amount CO2 cycling through the atmosphere (Figure 2). Trees need CO2 to make food, however, too much CO2 in the atmosphere can lead to what we now call global climate change.

Figure 2: In 2018, power plants that burned coal, natural gas, and petroleum fuels were the source of about 63% of total U.S. electricity generation, but they accounted for 99% of U.S. electricity-related CO2 emissions. Electricity generation from biomass, hydro, solar, and wind are virtually carbon neutral. (Source: U.S. Energy Administration)

Trees are a renewable natural resource which means they will naturally regrow or be replaced within a person’s lifespan. For many years Pennsylvania’s forests have been growing more wood volume than is being harvested. A sustainably managed hardwood forest in Pennsylvania can be completely harvested and replaced on average every 80 years. At the opposite end of the spectrum are fossil fuels, such as coal, gas, and oil. They are nonrenewable natural resources. They cannot be readily replaced and will eventually be completely used up.

Carbon neutral fuels, like firewood and wood pellets, neither contribute to nor reduce the amount of carbon dioxide in the atmosphere. Using carbon neutral fuels can help prevent this from happening. The carbon released from burning firewood or pellets is absorbed by the subsequent crop of new trees, which will grow to be the next source of carbon-neutral fuel……and the cycle continues.