EarthLabs > Climate and the Carbon Cycle: Unit Overview > Lab 1: Living in a Carbon World

Living in a Carbon World


Carbon is everywhere! Carbon is the fourth most abundant element in the universe and is the building block of life on Earth. Carbon exists in pure forms such as a diamond or graphite or in the millions of different kinds of carbon compounds scientists have currently identified. We use carbon compounds such as wood to build and heat our homes. Carbon compounds are responsible for combustion in the gas tanks of our cars and in the muscles of our bodies. This small six-proton atomic element carbon is central to life, gives us fuel for energy, and is critical to regulating our climate. Carbon can exist in gases, liquids and solids. In the non-living environment, we can find carbon in CO2 and other gases, carbonate rocks, coal, oil and gasoline. In the living environment, carbon can exist in proteins, carbohydrates, fats and nucleic acids and other carbon compounds made by living organisms. Carbon can exist in very small molecules with only two atoms such as carbon monoxide up to molecules that contain thousands of atoms such as proteins and DNA.

On Earth, carbon circulates through the land, the atmosphere and the ocean, creating what is known as the global carbon cycle. As carbon circulates, carbon compounds are converted into new forms of carbon compounds by processes such as photosynthesis, respiration and combustion. These processes also circulate carbon atoms between land, the atmosphere and oceans. Living organisms, from the largest tree to the smallest microbe, have key roles in converting carbon compounds and in circulating carbon through the global carbon cycle.

The global carbon cycle can be further subdivided into the geosphere carbon cycle and the biosphere carbon cycle. The geosphere carbon cycle operates at very long, slow time scales of thousands to millions of years and includes transforming processes such as lithification and volcanism. The biosphere carbon cycle operates on time scales of seconds up to hundreds of years and includes processes such as photosynthesis and respiration.

In Part A of this lab, you will trace the pathway of carbon from the atmosphere into trees where carbon can be stored for hundreds to thousands of years.

In Part B of this lab, you will go outdoors and measure the amount of carbon in a tree in your neighborhood.

In Part C, you will learn how important biosphere processes convert carbon compounds into new and different carbon compounds as carbon moves through the carbon cycle. Using a ball-and-stick carbon molecule kit and 3-D structures of carbon compounds, you will demonstrate how carbon can bond with other atoms and create many different types of carbon compounds.

After completing this investigation, you should be able to:

Keeping Track of What You Learn

Throughout these labs, you will find three kinds of questions. Your teacher will let you know which answers you should record and turn in.

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