Time for tea in the study of climate change

It is said that science is often stranger than fiction; that is certainly true where the Teabag Index (TBI) is concerned. The TBI is a project in which something as commonplace as a teabag — containing either green or rooibos tea — is helping researchers across the world understand climate change better. CREAF researcher and project participant Alba Anadon Rosell explained exactly how on Catalunya Ràdio’s Insostenibles programme. 

Fungi, bacteria, soil organisms and small invertebrates will feed on the carbon in the tea.

“Following the project’s established methods, we are burying bags of rooibos and green tea in the ground, separately to avoid their processes interfering with each other, and next year we will dig them up to find out how they have decomposed at their respective temperatures,” said Anadon. “Fungi, bacteria, soil organisms and small invertebrates will feed on the carbon in the tea, and we will see if the carbon becomes part of the microorganisms themselves or ends up being released in the form of emissions into the atmosphere.” 

In total, 60 researchers from 26 countries across the planet, including Brazil, Finland, Sweden, China and Catalonia, are taking part in the TBI project. Anadon’s study site is a remote forest in the Alt Pirineu Natural Park. Once each teabag has duly decomposed, an Austrian laboratory will gather together information from all the different countries and analyse how much carbon has been retained in the soil and how much released into the atmosphere as greenhouse gases. It will thus be possible to determine what type of carbon balance each ecosystem has and to precisely identify which of them make the best carbon sinks. Prioritizing and protecting such sinks, which keep the balance of the carbon cycle negative or only very slightly positive, is crucial to the fight against climate change. 

“The Teabag Index project’s data are helping us to improve predictive CO₂ emission modelling and to work out what direction scientists and policy-makers should be taking.” 

ALBA ANADON, CREAF researcher

Conserving the Alt Pirineu region’s natural sanctuary 

For the Insostenibles podcast, presenter Montse Poblet also spoke with Oriol Grau, a CREAF research associate and coordinator of the Alt Pirineu Natural Park Research Observatory. Grau took Poblet through the trees along the headwaters of the Noguera Pallaresa river to the Cherry Tree Forest, a forest that is among Catalonia’s most mature and one of those with the greatest soil microorganism biodiversity. “We are going to a sanctuary,” he told her. The research team will be burying teabags there too. 

Another policy decision the TBI project’s results might spur is that of engaging in more and better conservation of mature forests, given their carbon fixation capacity and role as reservoirs of biodiversity. Precisely on a farm near the Bosc de les Cireres, our researcher Lluís Comas coordinates a project that monitors biodiversity. It is the Global Biodiversity Monitoring Programme of Catalonia (SISEBIO)and has been monitoring biodiversity since 2017 with the aim of structuring management policies.