CO2MUCH - Think Global, Act Local

Carbon dioxide is a greenhouse effect gas essential for life. This gas in the air does not form a large percentage of the air around us, but it is essential to control its release into the atmosphere, since an excess of it can cause great harm. Although the greenhouse effect prevents the earth from losing too much IR radiation and suffering drastic falls in temperature at nights as a result, too much greenhouse effect causes the temperature to rise too much, causing glaciers to melt and the water level in our oceans to rise. Moreover, carbon dioxide is absorbed by the oceans which then become acidified which has harmful consequences for marine biodiversity.

Climate education needs to be a priority for our education systems, as stated in Article 12 of the Paris Agreement. This learning unit proposes to focus on the anthropogenic causes of carbon dioxide increases and its consequences for global warming and the oceans. There is a need to explore clean energy resources, such as fuel cells. Think globally and act locally through students' proposals to reduce our impact at their school and in their area.

Through the discovery of the use of carbon resources in the course of human history, students are led to study the combustion of carbon and methane. They carry out and study the chemical reactions of combustions and the balance equations, specifically combustion of carbon and methane. Students program sensors to detect water and carbon dioxide as combustion reaction products.

Greenhouse effect

The aim of this experiment is to prove that the greenhouse effect is caused by carbon dioxide.

Students measure the CO2 concentration and temperature in a jar containing water (Jar 1) and the same magnitudes in another jar (Jar 2) with the same water volume but in which students generate CO2 using a chemical reaction; which could be accomplished by adding 2 tablespoons of an effervescent fruit salt. Students can measure carbon dioxide in Jar 1 only at the beginning of the experiment, so only one CO2 sensor will be needed. A lamp is used to simulate the sun and to heat both liquids, making sure the distance from the lamp to both jars is the same. The jars can be black to increase and model thermic energy absorption.

Students program a microcontroller to record the time, the temperature and the CO2 concentration measured in ppm. Students compare data from both jars and come to conclusions about the relationship between the amount of carbon dioxide and the increase in temperature.

Ice core analyses

Students explore documents on how scientists learn about past climates. They analyse the Vostok curves and make the link between temperature increase and carbon dioxide concentration. They compare the impact of human activities to other phenomena.

This section covers the following laboratory activities on ocean acidification:

1. Students measure the pH of seawater samples.
2. In another laboratory activity, students discover how carbon dioxide affects the water’s pH.
3. Next, they study the mass loss of mussel shells in a more or less acidic environment.
4. In another experiment, students use a buffer solution to fix the pH problem.

This lesson can be approached at different levels of study and with different pH measuring equipment.

Hydrogen fuel cells have the advantage of not producing carbon dioxide. They produce electricity, heat and water from pure hydrogen and oxygen. Oxygen is abundant in the atmosphere, while hydrogen is the most common element in the universe. However, hydrogen does not exist on earth in its natural state. It therefore has to be produced artificially before it can be used as a fuel. Students will look at the processes of producing hydrogen and how a fuel cell works. They study water as a source material for hydrogen fuel cells as an electrolyser to produce hydrogen with solar cells. Then they use the hydrogen fuel cell to produce electricity. They determine the energy efficiency by calculating the energy delivered to the cell during the electrolysis and the energy delivered by the cell while the motor is running.