Australian tropical rainforests have become the first in the world to switch from a carbon sink to a carbon source, meaning they now release more carbon dioxide than they absorb. A new study found this reversal is due to increased tree deaths from climate change, specifically hotter and drier conditions, which have led to carbon lost from dying trees outpacing carbon gained by growing trees. This finding has significant implications for global climate models and carbon budgets, as it suggests other tropical forests may undergo a similar shift.

  Australian tropical rainforests have become the first in the world to switch from a carbon sink to a carbon source, meaning they now release more carbon dioxide than they absorb. A new study found this reversal is due to increased tree deaths from climate change, specifically hotter and drier conditions, which have led to carbon lost from dying trees outpacing carbon gained by growing trees. This finding has significant implications for global climate models and carbon budgets, as it suggests other tropical forests may undergo a similar shift. 

The "switch": -

The woody biomass of these forests has become a net source of carbon, a change observed over 20 years of data from 11,000 trees. 

The cause:-

 Climate change, particularly higher temperatures and drier conditions, is causing more trees to die, and the decay of these trees releases more carbon than the growth of new trees can absorb. 

The significance: -

This marks the first time a tropical forest ecosystem has been identified as having made this transition from a carbon sink to a carbon source. 

The implications: -

This development could mean that global climate models, which assume tropical forests will continue to act as a significant carbon sink, may need to be revised. If other tropical forests experience similar climate-induced shifts, it could lead to an underestimation of future global warming. 

MJF Lion ER YK Sharma