The activity carried out in the science laboratory has been allowed to highlight the negative aspects deriving from the climate changes taking place on Earth nowadays. These simple experiments, reproducible even at home by students, were the following:
1. What is the greenhouse effect?
In this activity, students saw how carbon dioxide can affect the Earth’s temperature and understood the Greenhouse Effect.
2 glass containers with lids
2 thermometers (accuracy 0.1 °C)
PURPOSE: This experiment demonstrates the effects of greenhouse gases on rising temperatures by comparing two glass containers. The first represents the current state of the air; the second assumes the air of the future, polluted and therefore saturated with CO2. The heat that the atmosphere accumulates inside it over the years was reproduced by means of sunrays from the window pointed at the two ‘atmospheres’ for one hour. A thermometer placed inside each glass jar showed, at the end of the experiment, that the temperature of the two systems was different. The one with CO2 become hotter than the one with ‘normal’ air (2°C difference).
2. Rising sea levels.
glass water bottle
jug of hot water
PURPOSE: The energy locked up by greenhouse gases is not only absorbed by the air: the water in the seas and oceans plays a key role in this process. By capturing energy from the atmosphere, water heats up and consequently its volume increases, raising the sea level.
A straw establishes the initial level of the water. In this experiment, sea water is represented by the water in the bottle which is placed in the bowl. By pouring hot water into the bowl, the bottle heats up. Consequently, the water in the bottle will also be heated. In this way, we students can see the increasing level of the water.
3. Air quality.
2 white cards
PURPOSE: The 2 white papers are exposed to two different environments: one heavily polluted (external environment with high traffic density) and the other clean (inside the laboratory). After a few minutes of exposure, students through observation at the microscope, have seen the differences and understood how polluted the Earth air is.
4. Consequences of acidification
glass containing vinegar
PURPOSE: This experiment reproduces the corrosion of the shell of marine animals. The eggshell is made of calcium carbonate so in few minutes the egg in the glass with vinegar shows the breakdown of its shell, due to the acidity of the vinegar. The same thing happens to the shells of marine species such as hermit crabs and molluscs animals.
5. Reflection capacity of the ground and reflectance phenomena
Global warming is a complex phenomenon both in its form and in its understanding. It is linked to many causes and many are its consequences; for example, global warming is related to the greenhouse effect and the melting of the Earth’s icecaps is linked to the albedo of the planet, i.e. the earth’s ability to reflect light. All un-reflected light is absorbed by the earth and contributes to its warming.
● Understanding the eﬀect of melting sea ice compared to the melting of glaciers and ice caps.
● Understanding the reflection of light according to the color of the material.
● Interactive map – Land cover, Sea level
● Virtual Laboratory experience – Albedo of different surfaces.
MATERIAL : A computer connected with the STELLE project platform
PROCEDURE: Observe the interactive map of the Earth and compare the difference in the colour of the ground in different years between 1993 and 2015; in the virtual laboratory, there are different sections of soil, with surfaces of different materials and colours.
A directional light source is simulated by the holographic generator, reflecting the characteristics of sunlight. In addition, there is an albedometer designed to measure the intensity of the light source and the intensity of the reflected light. The data read by the sensor is displayed on the laboratory monitor. With the measured light intensity data, it is possible to calculate the albedo of particular surfaces. By changing materials, it is possible to experimentally verify that different materials have different albedo values, marking each observation down in their notebook.
The materials and resources used for the development of the experiences were the common instruments a laboratory is equipped with (glasses, thermometers, chemical reagents, stationery material, etc.) and the connection with the platform of the STELLE project.
The audience made up of students and teachers from three different schools (a Polish school and two Italian schools) was involved through an active attendance, by means of interventions and considerations based on the results obtained in the laboratory by the teachers, as well as with the presentation of some experiments done by students.
The event had a great pedagogical reply. In fact, the students were able to see with their own eyes the reproduced effects, albeit on a smaller scale, of climatic changes such as rising temperatures, acidification of rain water, rising sea levels, etc. The students became aware of the seriousness of the problem and discussed what contribution each of them could give to reverse the trend.
The laboratory approach used is of fundamental importance in transferring knowledge to students. Other teachers should also use this methodology because it is a truly effective way to interest adolescents and to make them actively participate in their intellectual development and in the training of becoming new citizens of the world.