(c) Philipp Hummer (SPOTTERON)
Institution: AGES
Project lead: Taru Sandén
Spargelfeldstraße 191, A-1220 Wien
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Tea Bag Index

Can drinking tea help us to understand climate change? Yes, but we need your help! We would like you to become our research partner and participate in one of the largest experiments on soil decomposition processes at the moment.

What is it about?

The degradation of organic material is crucial for the growth and metabolism of plants and microorganisms: decomposition and mineralisation make the necessary nutrients available. This also releases the greenhouse gas carbon dioxide (CO2) into the atmosphere. Rapid degradation leads to increased CO2 emissions, while slow degradation increases carbon storage in the soil. In order to better understand the global CO2 cycle, it is therefore important to gather more information about the decomposition rates in different soils.

With the tea bag method, even lay people worldwide can make a valuable contribution to science and the environment: they simply bury tea bags in the ground, dig them out again after a while and weigh them. Weight loss indicates how much plant material, in this case tea, has been decomposed. This simple and cheap method for determining decomposition rates has been scientifically confirmed and initiatives have already been launched in many countries around the world.

With these experiments, comparable data can be obtained worldwide, especially from regions for which no corresponding information is yet available.

Tea bag method

You can find the current flyer with the exact method description as pdf for download at this link

At the end of this page you will also find a video describing the method in detail.

Would you like to participate?

Interested parties can now participate in the project and help to investigate the decomposition processes of plant material in soil. As part of the project, tea bags will be buried on a green area (meadow, field, forest ground) and GPS data will be recorded. After three months, the bags will be dug out again, dried, weighed and the results, including GPS data, entered into a map, which scientists can use to compare worldwide data. For example, the influence of location and soil composition on the rate of decomposition can be analysed.

App for Android

App for IOS

Interactive map:

Roles in the project:

  • Project management and Tea Bag Index Team: overall coordination of the project including data management
  • Project participants (Citizen Scientists): data collection and processing on the basis of their own interests

If you are interested in participating in the project, please contact the global Teatime4Science project team or send an e-mail to the local partners: This email address is being protected from spambots. You need JavaScript enabled to view it.


Gefördert durch:
Logo SparklingScience NEW 250718

Logo ISBlang 4c


Tagged under
  • land use


Read 120 times| Last modified on Wednesday, 23 September 2020 13:11

twitter facebook