Natural carbon sinks have been shown to play an essential role in mitigating climate change, but what exactly is a carbon sink?
A carbon sink is a natural or artificial reservoir that accumulates and stores carbon dioxide from the atmosphere for an indefinite period. The main natural carbon sinks are the world’s oceans, plants, and soil; and according to new research from the University of Birmingham, the most significant terrestrial carbon sinks are young forests.
The new findings may come across as surprising, mainly because most think dense tropical forests having tall and thick canopies would be the most important terrestrial carbon sinks. However, a landmark study in 2017 found that tropical forests have become net emitters of carbon. This means they release more carbon than they can take in. Although the emissions are through natural processes such as plant respiration and wildfires, the study claimed some of the emissions could be attributed to human activities like deforestation.
A young forest doesn’t mean that all the trees are very short; a young forest is defined as trees younger than 140 years. Typically these types of forests are in reforested areas that were previously used for agriculture or cleared by controlled fires. Examples of these forests around the world include the boreal forests in Canada and Europe and forests in the eastern states of the U.S. Researchers found that areas with forest regrowth absorbed more substantial amounts of carbon as a result of their young age and due to the fertilization of tree growth. Dr. Tom Pugh, one of the researchers with the Birmingham Institute of Forest Research, believes it is crucial to have a strong sense of where and why the carbon uptake is happening. Knowing this helps his team make targeted and informed decisions about forest management.
Dr. Pugh explained, “The amount of CO2that can be taken up by forests is a finite amount: ultimately reforestation programmes will only be effective if we simultaneously work to reduce our emissions.” China is working on a $100 billion large-scale reforestation program to help contribute to the world’s carbon sinks. Efforts like this combined with reducing carbon emissions are crucial for the planet in combatting climate change.