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.
By Jonathan Geyer and Dave Jackson
Carbon is a critical component of the greenhouse gas carbon dioxide. Greenhouse gases play an important role in Earth’s atmosphere; they help to trap heat close to Earth. Without greenhouse gases all the water on Earth would be frozen solid. However, when greenhouse gases like carbon dioxide become too prevalent in Earth’s atmosphere, more and more heat becomes trapped, therefore globally increasing Earth’s surface temperatures.
The compound of carbon dioxide consists of one carbon atom and two oxygen atoms. Humans inhale oxygen and exhale carbon dioxide. During photosynthesis, plants, like hardwood trees, take the energy from sunlight and use it to convert carbon dioxide and water into food. Through this process the carbon and oxygen atoms are separated. The oxygen is then released though the plants leaves; but the carbon is then used to make food for the plant. The carbon turns into a simple sugar called glucose. The glucose is then used by the plant for energy and to make other substances like cellulose and starch. Cellulose contains carbon and is an important structural component of the primary cell wall of green plants, such as trees.
Trees hold enormous amounts of water, making them very heavy. However, it is estimated that the average dry weight of a tree is 50% carbon. This means that on average each piece of lumber, solid wood furniture, wooden baseball bat, or anything made from solid wood is roughly 50% carbon by weight. The same carbon that a tree used to grow and build cellulose is stored within any wood product made from that tree.
The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to Earth and back into the atmosphere again. Since our planet and the atmosphere form a closed environment, the amount of carbon in this system does not change. Where the carbon is located, whether in the atmosphere or on Earth, is constantly in flux.
Most of Earth’s carbon is stored in rocks. The rest is in the ocean, atmosphere, plants, soil, and fossil fuels. Carbon flows between each reservoir in an exchange which has slow and fast components. Any change in the cycle that shifts carbon out of one reservoir puts more carbon in the others. Warmer temperatures on Earth are the result of changes that put additional carbon gases into the atmosphere.
Over the long term, the carbon cycle seems to maintain a balance that prevents all of Earth’s carbon from entering the atmosphere or from being stored entirely in rocks. This balance helps keep Earth’s temperature relatively stable, like a thermostat.
(Sources: NOAA's National Ocean Service; What is the Carbon Cycle and NASA Earth Observatory; The Carbon Cycle)