Climate change’s impact on the world’s forests has been a growing concern. Rising temperatures, droughts, wildfires, and disease outbreaks have been significantly affecting trees. Now, a new study has found that severe climate change could cause a notable slowdown in forests’ productivity.
The study, led by researchers from the University of Florida, analysed data from 1999 to 2020, including 113,806 measurements in non-plantation forests across the United States. The findings highlighted the severity of the issue of forest carbon sequestration, particularly in the U.S. Carbon sequestration refers to the process of capturing and storing atmospheric carbon dioxide.
The findings, published in the Proceedings of the National Academy of Sciences, found a significant regional imbalance in forest productivity, a key barometer of forest health that gauges tree growth and biomass accumulation, the university’s press release explained. Over the past two decades, the western US, which has experienced more severe climate change impacts, has shown significantly lower productivity, while the eastern US, experiencing milder climate effects, has seen slightly accelerated growth.
Forests play an important role in regulating the Earth’s climate. They work as carbon sinks that sequester approximately 25% of human carbon emissions every year, the statement added. However, their ability to store carbon depends on the balance between the positive and negative effects of climate change.
“We are witnessing changes in forest functioning as forest ecosystems respond to global change drivers, such as carbon dioxide fertilisation and climate change,” study author Aaron Hogan said in the statement. “It is the future balance of these drivers which will determine the functioning of forests in the coming years to decades.”
Factors such as droughts and forest pathogens have negative effects on productivity, but other drivers, such as carbon-dioxide fertilization, have been observed to have positive effects. It has been suggested that increased carbon dioxide levels enhance plant growth by increasing photosynthesis.
According to the researchers their study suggests that predictions about climate and sea-level rise may be too optimistic because ecosystems are likely to store less carbon in the future. If that happens then there will be more carbon in the atmosphere, which will accelerate climate change and global warming.
Previous studies have also warned that the world’s ecosystem capacity to absorb carbon might be declining. For instance, a new study by Nasa published in December 2023, showed thawing permafrost and carbon-rich runoff from Canada’s Mackenzie river is causing a part of the Arctic Ocean to release more carbon than it can absorb.
These studies highlight the importance of the need for curbing global greenhouse gas emissions because without it forest and sea carbon sinks are likely to weaken.