International study challenges whether global warming increases forests’ ability to absorb CO₂

Global warming is lengthening the growing season of forests, a phenomenon that was thought to strengthen their role as carbon sinks, but a scientific study casts doubt on this and other assumptions.

Global warming is lengthening the growing season of forests, a phenomenon that was thought to strengthen their role as carbon sinks. However, international research involving the Zaidín Experimental Station (EEZ-CSIC) and the Pyrenean Institute of Ecology (IPE-CSIC) concludes that the growth rate of conifers has a greater influence on wood production than the length of the growing season, and that drought associated with climate change can offset or even reverse this potential benefit for absorbing carbon dioxide (CO₂). Thus, the study, published in Science, challenges one of the most widespread assumptions about the role of forests as CO₂ sinks in a changing climate.

Forests play a key role in tackling climate change because trees capture carbon dioxide (CO₂) from the atmosphere and store it for years or even centuries in their wood. As temperatures rise, the growing season of trees becomes longer, allowing them to produce more wood, the main reservoir for the CO₂ they capture from the atmosphere. This has led to the belief that forests could absorb even more carbon in the future. However, the reality is more complex.

In fact, this study, which analysed how wood forms in conifers across more