Introduction
The agricultural and technological activities of the rapidly expanding species Homo sapiens are having increasingly profound and also devastating effects on Earth’s systems. With the industrial revolution that started at the end of the 19th century, fossil fuel consumption increased very rapidly. Everything we do that consumes energy derived from fossil fuels impacts the atmosphere and ultimately the oceans, biosphere, and geosphere. There are critical questions: How is this possible? What is the main element by which humans interact with Earth’s systems and climate?
The answer can be summed up in one word: carbon. Carbon is the most important and abundant component of fossil fuels. It is also one of the most common elements in the world. It is found all around earth systems, including the biosphere, atmosphere, hydrosphere, and geosphere.
In the atmosphere, carbon is found predominantly in molecules of carbon dioxide (CO2) and methane (CH4). Although a very little portion of the Earth’s atmosphere is composed of carbon dioxide and methane combined, both are important greenhouse gases that affect heat in the atmosphere negatively. Carbon is transferred between Earth systems through a series of pathways called the carbon cycle. One important function of the carbon cycle is the regulation of Earth’s climate. These four Earth systems are interconnected with each other strictly, and if we change the composition of the atmosphere, we will also cause changes to propagate through the biosphere, hydrosphere, and geosphere, altering our planet in ways that will likely not be beneficial to human welfare. In this lesson, students will learn which are the natural and artificial sources and sinks of carbon dioxide, how GHSs affect global warming, which strategies countries share to decrease the level of global GHGs. Students will be also asked to involve peers from others classes\schools in a research to set down a decalogue of good practices to save carbon budget in our daily routine.
"The Carbon Cycle and Climate Change" J. Bret Bennington Hofstra University