Activity in Kiel
Activity in Jena
Activity in Aquitaine area (France)
Activity in Norway
Activity in Romania
Activity in Southern Italy




What is the SchoolCO2web?

A bit of history

A few years ago, the SchoolCO2web was initiated by the Centre for Isotopic Research (CIO) and the Department of Education (IDO) from the University of Groningen, The Netherlands. They started a collaboration with three secondary schools in the Groningen area, aiming at integration of scientific research in the schools’ lessons. As scientific topics, the carbon cycle and fluctuations in the CO2-levels in the atmosphere were chosen. For this purpose, the participating schools were equiped with a CO2-meter and a weather station on their roofs. Automatically and at regular timepoints, these devices measure the CO2-concentration and the atmospheric conditions and send the results to a central database. The collected data are accessible for both school pupils and researchers and can thus be used for educational as well as scientific purposes. In 2008 the SchoolCO2web became embedded in the Carboschools project. This resulted in an increase in the number of participating measuring stations, to 14 at the moment, and an extension of the network over central and Southern Europe.  

Bridging the gap: bringing university science to secondary school pupils

Through the way the SchoolCO2web is set-up, science is brought closer to the pupils. The actual measurements are taken at their own school. In the database they can follow the results from day to day. And by looking at the measurements of other participating schools, they can even compare data between different locations.

However, the SchoolCO2web involves more than just measuring CO2-levels and reading the results from a database. Pupils also learn how to interpret these data. They become familiar with the requirements for good measurements and learn that obtained data should be relevant, reproducible and thrustworthy and how to achieve this.

The database of the SchoolCO2web is very extensive. This means that a solid scientific approach is required in order to draw meaningful and sound conclusions. Pupils learn how to extract valuable information by means of spreadsheet programs and statistics. This provides a tool to ultimately involve them in data analysis, which is an important skill within scientific research. Using the SchoolCO2web brings about an excellent opportunity to acquaint pupils with good scientific practices in a multidisciplinary topic, including mathematics, physics, chemistry and biology.

What can you do with the SchoolCO2web?

The SchoolCO2web offers a database with CO2-concentrations and atmospheric conditions collected by the associated measuring stations. This database can be used by scientists as well as teachers and pupils and of course the level of complexity of the research can be adapted according to the wishes of the user.

To facilitate the use of the SchoolCO2web by teachers and pupils, a user guide (pdf, 2MB) is available (Une version française abrégée existe aussi). Most importantly this contains:

  1. a manual (pdf, 189 KB) for working with the data of the SchoolCO2web
  2. examples of interesting dataseries extracted from the database plus an explanation of the observations (pdf 1.2MB)
  3. some tools to enable more advanced usage of the SchoolCO2web data (pdf, 56KB)
  4. suggestions for teachers to integrate the SchoolCO2web and other CO2-measurements in their lessons at school (pdf, 107KB)


Carbon cycles, Climate effects and Carboschools


The carbon cycle around  1990The carbon cycle depicts the flow of carbon around the world

Carbon is found in billions of tons all around our planet. A general overview of the system shows five major carbon reservoirs:

  1. the atmosphere,
  2. the terrestial biosphere,
  3. the oceans,
  4. the sediments (including fossil fuels)
  5. the Earth’s interior.

Continuously, carbon is exchanged between these reservoirs by means of the carbon cycle, which was initially discovered by Joseph Priestley and Antoine Lavoisier in the 18th century. This biogeochemical exchange occurs via a wide variety of chemical, physical, geological and biological processes and allows the recycling of carbon and its reusage in the biosphere.


Based on the transfer rate of carbon between the reservoirs and the size of these reservoirs, carbon subcycles can be distinguished. For example, the shortterm carbon cycle has a high transfer rate, but a relatively small reservoir. This cycle comprises the interactions between the atmosphere and the biosphere, such as CO2-fixation by plant photosynthesis and CO2-emission by animal respiration. The longterm carbon cycle, on the other hand, has a low transfer rate, but a large reservoir and mainly involves the formation and utilization of fossil fuels and other carbon-containing sediments. Together with others, these subcycles control the atmospheric levels of CO2.


Disturbing the carbon cycle – a risk for climate change

The (im)balance in and between the subcycles is a hot topic in the current debate on global warming. As a result of the increased energy demand of the worlds’ population, an imbalance is introduced in the carbon cycle. Fossil fuels are expended at a high rate for shortterm benefits, like energy, resulting in an enormous CO2-emission (approximately 29 billions of tons per year in 2007). However, only 55 – 60% of the atmospheric CO2 can be absorbed again by the Earth’s carbon sinks, like oceans and plants and forests. The remaining 40 – 45% of the CO2 thus stays in the atmosphere and acts as a greenhouse gas. A picture of the world shows an overview of the CO2­emission due to combustion of fossil fuels per capita.

CO2 emission per capitaIn 1988, the United Nations established the International Panel on Climate Change (IPCC) to report on the risks of climate change. Nowadays, the relation between the increase in atmospheric greenhouse gases (e.g. carbon dioxide, methane, nitrous oxide) and the increase in global temperature is generally accepted. Furthermore, in 2007 the IPCC report stated that "most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations", thus strongly focussing on the influence of human behaviour on the climate.


Not only does an increase in global temperature imply a severe risk for individual countries, threatening with floods, bad harvests or droughts, but climate change also can have more extensive effects, especially on the most vulnerable countries and regions in the world. As the Norwegian Nobel committee said in its announcement speech "Extensive climate changes may […] induce large-scale migration and lead to greater competition for the earth’s resources. [ …] There may be increased danger of violent conflicts and wars, within and between states". The committee therefore decided to award the IPCC and Arnold (Al) Gore Jr. with the Nobel Peace Price 2007 for "their efforts to build up and disseminate greater knowledge about man-made climate change and to lay the foundations for the measures that are needed to counteract such change".


Importance of standardized measurements and a role for Carboschools

With the undeniable rise in global temperature and greenhouse gas concentrations, the worldwide interest in climate research is booming. However, climate change is hard to measure and the available data are often difficult to interpret and to translate into immediate climate effects. Large datasets are required and furthermore all measurements should be performed in a standardized way to allow comparisons between different studies. It has happened too often that wrong conclusions were drawn just because data sampling was different and thus uncomparable.

Within the framework of worldwide climate change research and initiatives, the carboschools project SchoolCO2web aims at creating awareness of the nature of climate change, but moreover of the requirements for proper measurements. Questions that the participating pupils should become familiar with are amongst others:

  1. what actually is a measurement?
  2. when can I trust my measurement?
  3. is the number on the meter the exact reflection of the CO2-concentration in the air?
  4. which factors do influence the CO2-concentrations?
  5. when can I say something about a trend in the measured concentrations?


Atmospheric CO2 cycles in a nutshell

Layers of the atmosphereThe atmospheric composition





The atmosphere surrounding our planet is build up of several layers of gases. It protects life on Earth by absorbing ultraviolet solar radiation, by warming the surface through heat retention (greenhouse effect) and by reducing extreme temperature differences between night and daytime. Roughly 80% of the total of the atmospheric gases is located in the troposphere, which is the lowest of five principal surrounding layers. The troposphere starts at the earth’s surface and extends to approximately 7 kilometers at the poles till about 17 kilometers at the equator. Tropos in Greek means "turning" or "mixing", referring to turbulent mixing processes that occur in the troposphere, influencing its structure and behaviour. Most of the phenomena that are associated with our day-to-day weather take place in this layer. And most of the emitted CO2 ends up in the troposphere, so this is the layer to investigate in CO2-research.






CO2-concentrations in the troposphere

As a result of the high turbulence in the troposphere, the air becomes mixed and gas-concentration differences level out. The strength of this effect increases with altitude. Near the surface, high levels of CO2 are produced, as a result of for example animal respiration or emission by industry, while on the other hand CO2 is taken up again by plants to use in photosynthesis. Combined with a relatively low mixing of the air, this results in strongly fluctuating CO2-concentrations when measured close to the surface, which reflect the very local situation rather than an average for a larger area.

Monthly mean CO<sub>2</sub> concentration in Mauna Loa Station




Professional CO2-research stations are therefore usually positioned at a high location. The measuring station at Mauna Loa (Hawaii) is a good example. It is located at a volcano at an altitude of 3400 meters. The figure depicts data obtained at this station showing the monthly average CO2-levels. As can be seen, the levels oscillate over a period of one year. These oscillations are caused by seasonal effects. During the last years, the average CO2-level increased with almost 2 ppm per year, reflecting the combustion of fossil fuels.




Ideally, only high altitude measuring stations would thus be used for investigating atmospheric CO2-levels. However, for financial and practical reasons this is not always possible. Still, also close to the Earth’s surface good data can be obtained, as long as the experimental setup is well thought through and the collected data are filtered to leave only the relevant measurements. The SchoolCO2web meters are examples of such low altitude measuring stations.







Details of the Vaisala CO<sub>2</sub>-meter

The Vaisala CO2-meter


The SchoolCO2web participants are equiped with a Vaisala Carbocap GMP343 CO2­-meter on their roof, so at a heigth of maximally 10 to 20 meters. This type of CO2-meter is a so called non-dispersive infrared sensor. The figure shows a schematic overview of the measuring unit. The Vaisala contains a lamp which emits infrared light. Via a mirror this light is reflected to a detector for infrared light. On its way, the light encounters CO2-molecules in the air, which absorb part of the light. As a result, less light will reach the detector. The difference in intensity between emitted and detected light is a measure for the number of light-absorbing CO2-molecules and thus for the CO2-concentration in the air. In addition, every school got a Davis Vantage PRO weather station installed, which measures, for example, air pressure, temperature and humidity and sends the data to the Vaisala. With help of these values, the Vaisala can correct its own CO2-measurements for changes in weather conditions. All obtained data are reported to the SchoolCO2web and collected in the database.




What can you do with the data? A case: Inversion, an example of CO2-fluctuations

One of the main aims of the SchoolCO2web is to show that fluctuations in the CO2-levels are just due to the measuring conditions or the local situation instead of reflecting a general trend in atmospheric CO2-concenterations.

CO2 concentration measured in the Carl-Zeiss Gymnasium in Germany and in the Maartenscollege in the Netherlands from November the 11<sup>th</sup> to the 14<sup>th</sup> of November


An illustrative example of CO2-fluctuations is shown in figures bellow. For the same period of time, the 11th till the 14th of November 2008, CO2-concentration data are downloaded from the SchoolCO2web and represented in graphs for both the Carl-Zeiss-Gymnasium in Jena, Germany and the Maartenscollege in Haren, The Netherlands (figure left). The grey and white areas in the graph represent night and day respectively. A peculiar phenomenon can be observed at the 13th and 14th of November, when there is a large increase in CO2-concentration during the night and a drop during the day. This effect is called inversion, a situation in which the air next to the Earth is trapped by a layer of warmer air above it and thus, including the CO2, is kept close to the Earth. Following the CO2-concentration during the day, this is what happens:

  1. when daylight starts, plants can perform photosynthesis and fix CO2, resulting in a reduction of the atmospheric CO2-level. Simultaneously, the sun heats the earth and the earth emits heat to the air, thereby evoking turbulence and mixing of the surface air layer with layers higher in the atmosphere. This results in an even distribution of a relatively low CO2-level through the layers during daytime.

  3. In the evening, the earth cools down rapidly. As a result, the air close to the surface also cools down. The higher air layers, however, are still warmer and function as a blanket to prevent mixture of the air. In addition, plants stop photosynthesizing when it becomes dark and can no longer fix CO2 from the atmosphere.


As a result, all the CO2 exhaled by organisms accumulates in the surface layer, where also the CO2-meter is located. The meter thus registers a higher CO2-concentration during the night than during the day.

CO2 concentration and wind speed measured in the Carl-Zeiss Gymnasium in Germany from November the 11<sup>th</sup> to the 14<sup>th</sup> of November



Although a strong inversion can be seen at the 13th and 14th of November, this phenomenon is almost absent at the 11th and the 12th of November. Why is that?


The answer to this question is revealed in the right figure. In addition to the CO2-concentration measured at the Carl-Zeiss-Gymnasium, also the wind speed at this location is plotted. As can be seen, the wind speed was relatively high at the 11th and 12th of November, causing the atmosphere to mix and thereby preventing inversion. During the last days there was hardly any wind, resulting in poor mixing of the atmosphere and thus inversion could be observed.




Additional information & support for SchoolCO2Web

Support website: additional information and support to join, build and maintain in measuring CO2 data together with other schools in Europe can be found on this website.

Other CO2 sensor: you will find information about another CO2 sensor, which is not used for schoolCO2web but can be useful for class experimentations.


SchoolCO2web tutorial 02 Correlation between CO2 conc and av wind speed

SchoolCO2web tutorial 03 Filtering CO2 levels in a well mixed atmosphere

SchoolCO2web tutorial 04 Calculation of the average CO2 levels

link to CarboEurope website
link to Carboocean website
link to EPOCA website
Cordis FP7 homepage