Glossary

Expanded clay is ground clay that is fired in a kiln at 1,200 degrees Celsius. During combustion, the material expands spherically to four to five times its original volume.

In botany, transpiration describes the evaporation of water through the leaves of plants.

Humidity indicates the proportion of water vapour in a gas mixture. Since gases cannot absorb an unlimited amount of water, the relative humidity, on the other hand, describes the actual water content in relation to the physical maximum of a gas mixture.  

Fertilisers containing nitrogen as the main nutrient element for plants. Nitrogen is considered the most important form of fertiliser and is taken up directly by plants in the form of nitrate, ammonium and urea. There are limitations on the amount of nitrogen fertiliser that should be used, as high levels of nitrate leaching endanger the

The goal of green manure is to improve the soil. Certain plants are left in the field or planted for this purpose and then incorporated into the surface of the soil or used for mulching. This improves soil life, builds up humus, protects the soil from erosion, improves the supply of nitrogen to the following

The sun’s rays hit the earth in the form of ultraviolet radiation. A part is reflected. On their way into the atmosphere, gases such as carbon dioxide (CO2), ozone and water vapour are reflected back to earth in the form of infrared radiation. This effect warms up the earth like a greenhouse and ensures a

The adjective “eutrophic” has a Greek origin and means “rich in nutrients” but also “over-fertilised”. The process of eutrophication describes the excessive growth of plants in lakes due to an increased nutrient intake. Nitrogen and phosphorus compounds in particular cause eutrophication. The degradation of the plant masses leads to a drop in the oxygen content

In chemistry, the group of substances that consists only of carbon and hydrogen is called hydrocarbons. They are mainly found in fossil fuels. The molecular formula is CmHn.

In the thermohaline circulation, four of the five oceans are connected by ocean currents. The circulation is caused by differences in temperature and salt.

This approach, invented by the German chemist Michael Braungart and the American architect William McDonough, puts product cycles in a holistic context. The goal is not to dispose of the substances and materials used in products as waste, but to reuse them. That means continuing to use it after using it for another purpose.