An audio podcast on how fossil fuel burning fits into the global carbon cycle, concentrated on how the excessive fossil fuel burning has accelerated the production of greenhouse gases. LISTEN TO THE PODCAST

The carbon cycle is a natural process through which carbon circulates throughout our environment. Part of the cycle actually occurs outside the cycle per se. A certain amount of pure carbon becomes fixed in sinks below the ground and oceans: plants and animals die, and sometimes become buried before decay is complete; under certain conditions of pressure and temperature as well as anaerobic decay they ultimately compress into substances such as coal, peat, natural gas, and oil, substances we now call fossil fuels. Over 300 million years ago, this process was very robust. Large amounts of coal were being laid down. In fact, this era took its name–the Carboniferous Period–from this activity.

Today, we are rapidly using these fossil fuels to power our factories, homes, and daily lives. Estimates say that 90 percent of the energy we use in the United States alone comes from fossil fuels.

The problem is that when the carbon in fossil fuels burns, its molecules unite with oxygen to form carbon dioxide, a greenhouse gas. And, ever since the dawn of the Industrial Age, atmospheric levels of carbon dioxide have exploded.

The longest continuous record of atmospheric carbon dioxide concentrations is compiled by scientists working on Mauna Loa in Hawaii. Their data shows that--between 1959 and 2004--the concentration of carbon dioxide in the atmosphere increased from about 317 parts per million (ppm) to 377 ppm. And that figure continues to rise, increasing the chances that the warming of our planet and the climate change it generates will at least continue, if not accelerate, in the coming years.

Fossil Fuels and Society

By Design: Fossil Fuels

After listening to this podcast, students will be able to describe the relationship between the burning of fossil fuels, t he production of greenhouse gases, and the carbon cycle.

• Identify and describe a range of local issues that have an impact on people in other places. (MD 6.0-B. 1a (Grade 6,7,8))
• All Earth processes are the result of energy flowing and mass cycling within and between Earth's systems. (NSF 3.2)
• Humans cause global climate change through fossil fuel combustion, land-use changes, agricultural practices, and industrial processes. (NSF.9.3)
• Life on Earth, including microbes, plants and animals such as humans, can influence climate substantially and has throughout the evolution of life on the planet. (NOAA 1f)
• The carbon cycle influences climate in a variety of ways, including seasonal interactions between the atmosphere, biosphere, and hydrosphere, and the formation and consumption of fossil fuels. Carbon dioxide, an important greenhouse gas, is removed from the atmosphere in the ocean and other parts of the Earth system through biologic and geologic processes. (NOAA, 4d)
• Interactions between components of the Earth's climate system result in changes to the system and produce emergent phenomena unique to the system. Human beings are an integral part of Earth's climate system. Human activities such as fossil fuel burning or deforestation can affect climate and alter the equilibrium of the climate system. (NOAA, 4h)
• Human activities have affected the land, oceans and atmosphere and have altered regional and global climate. These activities include burning fossil fuels, releasing chemicals into the atmosphere, reducing the amount of forest cover, and rapidly expanding farming, development and industrial activity. (NOAA 6b)
• The increased burning of fossil fuels since the start of the industrial revolution has increased the amount of greenhouse gases in the atmosphere. Because carbon dioxide remains in the atmosphere for many years (hundreds to thousands of years) before being removed by natural processes, this has contributed to Earth's warming. (NOAA 6d)
• The preponderance of scientific evidence indicates that the observed increase in global average temperatures since the latter part of the 20th century is very likely due to documented increases in human-induced greenhouse gas concentrations, primarily from the burning of fossil fuels. (NOAA 6e)
• The atmosphere covers the entire surface of Earth; thus, activities that effect climate (e.g., energy use leading to greenhouse gas release into the atmosphere) in one region affect human beings and other species worldwide. (NOAA 7e)

Carbon cycle, greenhouse gases, fossils, geography

• Back before the Dinosaurs Before students listen to this podcast, involve them in this activity: How did fossil fuels come to be? Through what processes were these fuels formed? Investigate this issue to help students understand the reasons fossil fuels are called a nonrenewable resource. This site might be a good place to start.
• Taking Inventory After students listen to this podcast, involve them in this activity: We know that the world is using a great deal of fossil fuel to go about its everyday business. But how much is a great deal? Ask students to accumulate and analyze data on fossil fuel consumption, using Internet and print resources. A good first destination in their quest is the International Energy Agency's pamphlet Key World Energy Statistics
• Where do we go from here? After students listen to this podcast, involve them in this activity: The burning of fossil fuels is certainly contributing to a pattern of rising temperatures around the globe. Given this, would we consider stopping their use? What can we use to replace these fuels in providing the power levels we have come to rely upon? Students could use these three questions as the central issues of a classroom debate. Students can find more details on these questions at sites like this one.